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1Back to top Go down    K100 KafeRacer Build on Sun Aug 03, 2014 2:25 pm

KafeRacer

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I thought I would post some pics of my Kafe Racer build.  There are alot of other cool projects on this site so thought I should share some of my own.

Here is the before pic.  It was such a nice donner bike I had a hard time chopping it up.



Here is the after:



I bought a ducati 916 tail section and a corbin seat off of ebay, I have always loved the look of the 916's so thought I would incorporate that into the build.



The frame needed some modification to build the structure to support the seat.  Also the front of the corbin seat needed to be truncated to fit the shape of the K100 tank.  I may try to stitch the German flag where the Italian flag is on the seat as a final finishing touch.  Mind you since these types of projects are never really finished, who knows when I will get to that.



I bought a smashed K100RS with the 16 valve engine, front end, and exhaust, unfortunately the transmission back was gone, so I had to source the transmission, paralever, final drive and tri-spoke rear wheel from ebay.  I havent got all of the parts yet but this will be a 16v, paralever bike when it is done. New mirrors are on route.  I also plan to go to a Dakota Digital 7400 Instrument Cluster.



Last edited by KafeRacer on Fri Apr 24, 2015 1:46 pm; edited 1 time in total


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Dave Evans
'Kafe Racer'
kaferacer.wordpress.com

1990 K75RT
1985 K100 Kafe Racer
http://kaferacer.wordpress.com
    

2Back to top Go down    Re: K100 KafeRacer Build on Sun Aug 03, 2014 2:28 pm

KafeRacer

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Here is the side view.  The clip on bars sure change the personality of the bike...  It handles well.  The 16v RS front end stops so much better then before.



Last edited by KafeRacer on Mon Aug 04, 2014 5:24 am; edited 1 time in total


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Dave Evans
'Kafe Racer'
kaferacer.wordpress.com

1990 K75RT
1985 K100 Kafe Racer
http://kaferacer.wordpress.com
    

3Back to top Go down    Re: K100 KafeRacer Build on Sun Aug 03, 2014 6:22 pm

Be made

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Good luck with the build. I myself did not like the commonality of cafe's (it seems thats all people are doing these days) or the riding position so I went for a cruiser style.

A lot of fun though, these conversions, and at least you end up with what you want.

I hope it goes well for you. Will look forward to seeing your finished bike

    

4Back to top Go down    Re: K100 KafeRacer Build on Wed Aug 06, 2014 4:56 am

Fentible

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Wow that's nice, the ducati tail unit looks really good. I know what you mean about chopping an already nice bike. I've just finished renovating a naked K100 and keeping it standard because I couldn't bear to start hacking it up.

I'm hopefully going to follow the café racer route from the pile of spares that I got and I need to think about how it will look.

I managed to pick up a paralever rear end and gearbox for very little money but I'm mating it to a standard 8v motor because I prefer the simplicity. But that as far as I've got at the moment.

    

5Back to top Go down    Donner/donor on Wed Aug 06, 2014 11:41 am

Glacial

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Donner as in kebab
Donor as in rip my heart out.

That was such a lovely example, I would have happily swapped you my slightly dog-eared version to cut up and I would have kept the pristine original one.


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BMW K75S 1990 (ABS removed)
    

6Back to top Go down    Re: K100 KafeRacer Build on Wed Aug 06, 2014 10:07 pm

Waz

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The Ducati tail and seat are the best I have ever seen. Very good look.


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1987 K100 RS
1997 R1100R
1996 R1100GS
    

7Back to top Go down    Re: K100 KafeRacer Build on Mon Aug 11, 2014 11:51 pm

floyd

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The 748/916 - 998 are in my opinion the best looking bikes ever styled. Im yet to have the pleasure of riding one, but do dream of owing a 748 one day.

A mate of mine has a beautiful 748R. What a bike. 



Your mod is looking nice and tidy.


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K100 with lots of K1100 bits - mongrel of a thing...
    

8Back to top Go down    Re: K100 KafeRacer Build on Tue Aug 12, 2014 11:41 am

KafeRacer

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Drool..... Those 916 and 748 are gorgeous.  Would love to run the K100 Exhaust up under the tail section, but I expect I will need a lot more welding experience before I attempt that.

Cheers.


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Dave Evans
'Kafe Racer'
kaferacer.wordpress.com

1990 K75RT
1985 K100 Kafe Racer
http://kaferacer.wordpress.com
    

9Back to top Go down    Re: K100 KafeRacer Build on Wed Aug 13, 2014 3:19 pm

KafeRacer

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I got the paralever installed along with a progressive suspension shock and an RS belly pan.



New headlight and mirrors also installed. Next step is to install the Dakota Digital instrument cluster as soon as the wiring harness arrives.



Cheers. 

Dave.


__________________________________________________
Dave Evans
'Kafe Racer'
kaferacer.wordpress.com

1990 K75RT
1985 K100 Kafe Racer
http://kaferacer.wordpress.com
    

10Back to top Go down    Re: K100 KafeRacer Build on Wed Aug 13, 2014 3:47 pm

Waz

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Is that progressive shock upside down? If yours is the right way mine is upside down.


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1987 K100 RS
1997 R1100R
1996 R1100GS
    

11Back to top Go down    Re: K100 KafeRacer Build on Wed Aug 13, 2014 3:54 pm

KafeRacer

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LOL, I am not sure, but it should not matter.  All of the photos on their web site show the snubber down.

Cheers Dave.


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Dave Evans
'Kafe Racer'
kaferacer.wordpress.com

1990 K75RT
1985 K100 Kafe Racer
http://kaferacer.wordpress.com
    

12Back to top Go down    Re: K100 KafeRacer Build on Wed Aug 13, 2014 4:02 pm

Waz

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That would be right, two ways to do it and got it wrong.


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1987 K100 RS
1997 R1100R
1996 R1100GS
    

13Back to top Go down    Re: K100 KafeRacer Build on Wed Aug 13, 2014 4:13 pm

KafeRacer

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Its ok,  That is the correct position for you as you are located in the southern hemisphere. That shock is mounted in the the 'down under' position.

Very Happy


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Dave Evans
'Kafe Racer'
kaferacer.wordpress.com

1990 K75RT
1985 K100 Kafe Racer
http://kaferacer.wordpress.com
    

14Back to top Go down    Re: K100 KafeRacer Build on Wed Aug 13, 2014 4:25 pm

blaKey

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Nice bike Waz, no doubt about it, but...


Blue zip ties?   Shocked  Very Happy


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Neil
K100RS 1986 RED!
K100RT 1987 (now nekkid with red bits)

Remember Rule No. 6
    

15Back to top Go down    Re: K100 KafeRacer Build on Wed Aug 13, 2014 4:57 pm

Waz

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Upside down shock and blue zip ties are an indication of the shody workmanship.

How does the light work? I don't see a battery.


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1987 K100 RS
1997 R1100R
1996 R1100GS
    

16Back to top Go down    Re: K100 KafeRacer Build on Wed Aug 13, 2014 11:38 pm

KafeRacer

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I relocated the battery and fuel computer up out of the way under the seat and tail section.



Cheers.

Dave.


__________________________________________________
Dave Evans
'Kafe Racer'
kaferacer.wordpress.com

1990 K75RT
1985 K100 Kafe Racer
http://kaferacer.wordpress.com
    

17Back to top Go down    Instruments Installed on Sat Oct 04, 2014 2:03 am

KafeRacer

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After a lot of wiring I got everything installed and working on the Dakota Digital instrument cluster.  I had to use an inductive sensor to count the brake rotor bolts to get the speedometer to work, I also had to put a filter on the power that powers the instruments as I was getting ignition noise that was being picked up which was causing the speedometer to give erratic reading.  The filter solved that.



In order to get neutral indication working, and the start in neutral bought a gear indicator circuit board from robmack which also gave me the 7 segment led screen that I mounted in the top triple clamp.




I am very please with how it has turned out, I maintained all of the features from the stock cluster in a much smaller package.




I also have been busy making the under tail cover and fender to keep spray from the rear wheel getting where it shouldn't.





I also got my last LED signal lights installed, inside the tail section to improve visibility from the side.


__________________________________________________
Dave Evans
'Kafe Racer'
kaferacer.wordpress.com

1990 K75RT
1985 K100 Kafe Racer
http://kaferacer.wordpress.com
    

18Back to top Go down    Re: K100 KafeRacer Build on Sat Oct 04, 2014 9:59 am

Mossy1200

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Nice I was thinking about the gear indicator in the same spot.
Was wondering about using a oil level sight glass.
Is yours a washer or is there glass between the digital on that.

    

19Back to top Go down    Re: K100 KafeRacer Build on Sat Oct 04, 2014 12:32 pm

KafeRacer

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I mounted the led display in aluminum channel, and the cover is just thin aluminum cut with a hole saw and the center filed out in a rectangle.  No glass or plexi over the LCD.  So we will see how it survives rain wise.  Worst case they are only about 2$ to buy another one.


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Dave Evans
'Kafe Racer'
kaferacer.wordpress.com

1990 K75RT
1985 K100 Kafe Racer
http://kaferacer.wordpress.com
    

20Back to top Go down    Re: K100 KafeRacer Build on Sat Oct 04, 2014 1:08 pm

Mossy1200

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@Waz wrote:Upside down shock and blue zip ties are an indication of the shody workmanship.

So is wrinkles in duct tape.

    

21Back to top Go down    Remus Collectors on Sat Oct 11, 2014 8:58 am

KafeRacer

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I managed to find a Remus collector from eBay.  Won if for $40 USD plus that much again for shipping.  



Unfortunately the slip-on is missing the the baffle and rear cap.



Here is it is after some sanding, wet sanding, and polishing.  Still a lot more polishing to come. Now the search for a baffle and end cap, or other slip-on with a 3″/76mm inlet.  Any ideas.



__________________________________________________
Dave Evans
'Kafe Racer'
kaferacer.wordpress.com

1990 K75RT
1985 K100 Kafe Racer
http://kaferacer.wordpress.com
    

22Back to top Go down    Re: K100 KafeRacer Build on Sat Oct 25, 2014 6:53 am

KafeRacer

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Does anyone have any rebuild instructions for front forks for a 1990 K100RS or K1.

It is the earlier version marzocchi damper (left in the photo).  I plan to rebuild but my manual only has the earlier forks.  I will be putting in progressive suspension springs. and replacing all the oil an seals.


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Dave Evans
'Kafe Racer'
kaferacer.wordpress.com

1990 K75RT
1985 K100 Kafe Racer
http://kaferacer.wordpress.com
    

23Back to top Go down    Re: K100 KafeRacer Build on Sat Oct 25, 2014 9:45 am

Inge K.

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@KafeRacer wrote:Does anyone have any rebuild instructions for front forks for a 1990 K100RS or K1.

OEM manual for K1/RS16V you find here.


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Inge K.
K100RS -86. (first owner), K1100LTSE -94.
    

24Back to top Go down    Re: K100 KafeRacer Build on Sat Oct 25, 2014 1:42 pm

KafeRacer

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@Inge K. wrote:
@KafeRacer wrote:Does anyone have any rebuild instructions for front forks for a 1990 K100RS or K1.

OEM manual for K1/RS16V you find here.

Excellent find,  The English manual did not work, but the German one did, that coupled with some google translate did the trick.  Got the info I needed.  Forks are all disassembled now and I have the torques for reassembly.

Thanks.


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Dave Evans
'Kafe Racer'
kaferacer.wordpress.com

1990 K75RT
1985 K100 Kafe Racer
http://kaferacer.wordpress.com
    

KafeRacer

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Received a nice used Remus exhaust from Germany last week. It was from a GSXR 1100 so it was designed to be mounted on the other side of the bike. No problem I just took the canister apart and turned the aluminum tube around 180 deg so the Remus logo can be seen, drilled new mounting holes and plugged the unused ones.





Headers are all polished up now.  I painted the intake pipes on the collector black as it was much too intricate to try to polish all the nooks and crannies around the four pipes.



I also started the fork rebuild. I have everything dismantled and cleaned now.



Those springs are progressive suspension springs that I hope will firm up the front end.  Everything looks in good shape including the slider bushings.



__________________________________________________
Dave Evans
'Kafe Racer'
kaferacer.wordpress.com

1990 K75RT
1985 K100 Kafe Racer
http://kaferacer.wordpress.com
    

26Back to top Go down    Dis-assembly Time on Mon Nov 24, 2014 1:04 pm

KafeRacer

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I spent most of Saturday night striping the bike down in order to swap the 8V engine for the 16V.  Only took about 2 hours to create a large pile of parts on the floor. Too bad re-assembly won’t be as quick.


Here is the new 16V engine sitting on a modified transmission jack which bolts to the four M8 belly fairing bolts on the oil pan, this setup worked very well.  It raises high enough to be at a very good working level where I could re-assemble the clutch and bolt on the transmission and all of the engine accessories.





 Here are the 16V throttle bodies with 8V throttle cable tabs and guide as well as the shaft in #4 TB swapped out with the one form the 8V TB so the 8V TPS sensor could be installed and set. Next step will be to modify or build an air box to fit.



__________________________________________________
Dave Evans
'Kafe Racer'
kaferacer.wordpress.com

1990 K75RT
1985 K100 Kafe Racer
http://kaferacer.wordpress.com
    

27Back to top Go down    Paint Time on Thu Jan 15, 2015 2:19 pm

KafeRacer

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I recently got the frame back from the sand blaster. Sprayed a coat of self etching primer.


Now a coating of high build primer.  Next weekend will be the topcoat of urethane.




I had the wheels powdercoated and am very pleased with the results.



__________________________________________________
Dave Evans
'Kafe Racer'
kaferacer.wordpress.com

1990 K75RT
1985 K100 Kafe Racer
http://kaferacer.wordpress.com
    

28Back to top Go down    Frame installation and reassembly! on Mon Jan 19, 2015 3:57 pm

KafeRacer

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The frame is now all painted.  I am pleased with how it turned out.


The power unit is ready I will post more details later about how I have set up the bike with the 4v engine and 2v electronics.


 Starting to look like a bike again.


 Reassembly complete! I still have to install the my new wideband 02 sensor, balance the TB’s once I receive new rubber gaskets from BMW.  Then on to some tuning on a dyno.  Then it will be ready for the bodywork to get some more paint.  I am thinking about leaving the tail section and front fenders black (currently only black primer)  and painting the tank and radiator cover a bright orange.  However the maroon doesn’t look too bad so I might wait to do the orange.  Any thoughts? 


__________________________________________________
Dave Evans
'Kafe Racer'
kaferacer.wordpress.com

1990 K75RT
1985 K100 Kafe Racer
http://kaferacer.wordpress.com
    

29Back to top Go down    Electrical and Miscellaneous Small Jobs on Wed Feb 11, 2015 9:16 am

KafeRacer

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I built a flat aluminum plate on the under side of the frame beneath the gas tank to keep all of the wires neat.  After a lot of electric tape, wire looms and zip ties the wiring is all complete.


 Here is the 4v engine with 4v throttle bodies but the 2v air box which is was cut down by about an inch and had a fibreglass cover made for it in order to clear the frame. If you look close you can see the flat aluminum plate (painted black) on the under side of the frame.



Here are the throttle bodies from the other side and a new adjustable fuel pressure regulator. I am running the system at 3.5 bar as that is what the fuel injectors I have are designed for.



 Here it is with the barn door air flow meter installed and cone filter.  Also you can see the digital gauge for the wide-band oxygen sensor.  It is getting close to being ready to go to the dyno for some tuning.



The green bulb is the alternator charge light.  It illuminates when you turn the ignition on, and goes out once the alternator starts charging.



You can see the stainless steel drink container which is now the radiator overflow canister.



A close look at the structure that holds the fiberglass tail section.


__________________________________________________
Dave Evans
'Kafe Racer'
kaferacer.wordpress.com

1990 K75RT
1985 K100 Kafe Racer
http://kaferacer.wordpress.com
    

30Back to top Go down    Re: K100 KafeRacer Build on Wed Feb 11, 2015 4:12 pm

Two Wheels Better

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Dave, is that one of those 'new' Progressive-brand adjustable rear shocks? I have only seen a listing of the correct length for the Monolever swingarm and it's obvious you're using Paralever.

Never mind, I've read a previous post.
Rolling Eyes


__________________________________________________
1987 K100RS, Big Block '93 K11/K12 hybrid, '09 K1300GT, '07 K1200R, '04 R1150RT, '95 R100 Mystic, '77 R75/7.
Have we accomplished half of what we dreamt we would? There may still be time.
    

31Back to top Go down    Re: K100 KafeRacer Build on Wed Feb 11, 2015 4:24 pm

KafeRacer

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@Two Wheels Better wrote:Dave, is that one of those 'new' Progressive-brand adjustable rear shocks? I have only seen a listing of the correct length for the Monolever swingarm and it's obvious you're using Paralever.

Never mind, I've read a previous post.
Rolling Eyes

Yes, it is Model 465-1101.  Its stock length for monolever so drops the back a bit when running it on a paralever bike. Lower is good for me.  The only thing is I had to put a washer behind the shock on the lower bolt to get the spring to not rub on the brake caliper.

If you are looking for a shock have you looked into RAM?  http://www.bskspeedworks.co.uk/ram-rear-shocks.html

Cheers. Dave.


__________________________________________________
Dave Evans
'Kafe Racer'
kaferacer.wordpress.com

1990 K75RT
1985 K100 Kafe Racer
http://kaferacer.wordpress.com
    

32Back to top Go down    Warm-Up Sequence on Sat Mar 07, 2015 10:45 am

KafeRacer

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Does anyone know how an L-Jetronic system is affected by the water temp sensor?

As I have installed a wide-band O2 sensor I can monitor the AFR.  The way it is configured now is as follows:

Bike Idles at 1070 shortly after starting and warm enough to not need choke - AFR hovers at 14.
Bike continues to warm up idle slowly increases to about 1250 after 10 minutes - AFR hovers at 14.
Note:  If I press the start button, it riches the mixture (as notes many places on the forum)  With the starter button pressed the AFR richens to about 12, release button and it goes back to 14.

After the bike warms up further there is a distinctive point where idle shoots up from 1250 to 1600, and AFR richens from 14, down to 11.8.  Note: Once this occurs, pressing the starter button no longer richens the AFR. At this point pressing the starter button has no affect on AFR.

I assume this is normal, and just a change in the fuel map after the bikes water temp reaches a certain point.

I am also assuming that if I adjust the AFR to be leaner at operating temp, it will be quite lean before the L-Jet changes to its operating fuel map.  Should I be concerned?  I am assuming not, and that running lean during warm-up will simply result in reaching operating temp faster?

I also notice that once the bike is at operating temp the spring tension on the air flow meter has virtually no affect on the AFR at idle. Does the L-jet not look at the air flow meter when the throttle is closed? And simply apply only a fixed amount of fuel?

Just looking for thoughts.



Last edited by KafeRacer on Sat Mar 07, 2015 11:03 am; edited 1 time in total


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Dave Evans
'Kafe Racer'
kaferacer.wordpress.com

1990 K75RT
1985 K100 Kafe Racer
http://kaferacer.wordpress.com
    

33Back to top Go down    Re: K100 KafeRacer Build on Sat Mar 07, 2015 12:33 pm

RicK G

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AFAIK you cant fit a O2 sensor to an L-Jetronic. If your engine is 16V then it's a Motronic


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"Every normal man must be tempted, at times, to spit upon his hands, hoist the black flag, and begin slitting throats."  from Mencken's 1919 Prejudices

Bikes 1993 K1100 LT, 1998 K1100 LT, 1993 K75 RT, 1996 K75RT, 1986 K75 GS, 1979 Z1300 Kawasaki X 2 for now
    

34Back to top Go down    Re: K100 KafeRacer Build on Sat Mar 07, 2015 12:38 pm

KafeRacer

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@RicK G wrote:AFAIK you cant fit a O2 sensor to an L-Jetronic. If your engine is 16V then it's a Motronic

I have a stand alone Innovate LC-2 Wideband O2 Sensor: http://www.innovatemotorsports.com/products/db.php

And I am running a 16V engine with with all 1985 8V - L-Jetronic FI system.

Cheers.


__________________________________________________
Dave Evans
'Kafe Racer'
kaferacer.wordpress.com

1990 K75RT
1985 K100 Kafe Racer
http://kaferacer.wordpress.com
    

35Back to top Go down    Re: K100 KafeRacer Build on Sat Mar 07, 2015 12:58 pm

RicK G

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So in essence all it does is monitor the AFR but doesn't interface with the L-Jetronic?


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"Every normal man must be tempted, at times, to spit upon his hands, hoist the black flag, and begin slitting throats."  from Mencken's 1919 Prejudices

Bikes 1993 K1100 LT, 1998 K1100 LT, 1993 K75 RT, 1996 K75RT, 1986 K75 GS, 1979 Z1300 Kawasaki X 2 for now
    

36Back to top Go down    Re: K100 KafeRacer Build on Sat Mar 07, 2015 1:07 pm

KafeRacer

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@RicK G wrote:So in essence all it does is monitor the AFR but doesn't interface with the L-Jetronic?

Exactly,  just gives me a readout on a little digital guage so I know accurately what the AFR is IOT tune the bike.  Since I have L-Jetronic on a 16V engine, and higher flow injectors that I am running at their designed 3.5 bar (I have an adjustable FPR) the factory set tuning is not correct any more.

I can adjust the AFR by changing the spring tension on the vane air flow meter.  Currently 5 tooth tighter seems about right, but I do plan to put it on a dyno and try a few settings as well as fool around with the timing to see what produces the best combo of HP and Torque.

What I am trying to understand a bit better is how the logic inside the L-Jet ECU works.

The bike certainly seems to run well, and sounds pretty mean with its current setup, and higher flowing REMUS exhaust.

Cheers.


__________________________________________________
Dave Evans
'Kafe Racer'
kaferacer.wordpress.com

1990 K75RT
1985 K100 Kafe Racer
http://kaferacer.wordpress.com
    

37Back to top Go down    Re: K100 KafeRacer Build on Sat Mar 07, 2015 1:18 pm

RicK G

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The water temp sensor will make it lean out as it gets hotter.
I do hope you are using the 8V temp sensor.
Graph for the sensor


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"Every normal man must be tempted, at times, to spit upon his hands, hoist the black flag, and begin slitting throats."  from Mencken's 1919 Prejudices

Bikes 1993 K1100 LT, 1998 K1100 LT, 1993 K75 RT, 1996 K75RT, 1986 K75 GS, 1979 Z1300 Kawasaki X 2 for now
    

38Back to top Go down    Re: K100 KafeRacer Build on Sat Mar 07, 2015 1:27 pm

KafeRacer

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@RicK G wrote:The water temp sensor will make it lean out as it gets hotter.
I do hope you are using the 8V temp sensor.
Graph for the sensor


Yes I am using an 8V Temp Sensor,  The interesting thing is AFR stays the same up until a certain point then all of a sudden it richens alot.  (By about as much as the starter button richen the AFR).  It seems like what is happening is once temp reaches a certain point something changes in the L-Jet ECU.

Cheers.


__________________________________________________
Dave Evans
'Kafe Racer'
kaferacer.wordpress.com

1990 K75RT
1985 K100 Kafe Racer
http://kaferacer.wordpress.com
    

39Back to top Go down    Re: K100 KafeRacer Build on Sat Mar 07, 2015 2:13 pm

charlie99

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if its running lean at idle

you could try to adjust the air bypass on the afm ..( 5mm allen key through the air box at the top and behind a rubber bung ...if its still there )

by closing the screw , less air goes through the port so more air affects the flap opening .
there is a certain flow rate that this becomes ineffective

this Is also where you would adjust the mix for idle co  on standard machines ....( there is at least one documented way to do this "lean drop method " )


have you thought about running the injectors at 3 bar perhaps ....they work quite well at that pressure ....the 3.5 bar would reflect the normal operating pressure in a given application ...like an m3 car  but work happily  from 2.8 bar up

good luck


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'86 K100 RT..#0090401 ..."Gerty" ( Gertrude Von Clickandshift ) --------O%O
    

40Back to top Go down    Re: K100 KafeRacer Build on Sat Mar 14, 2015 4:43 am

KafeRacer

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Well I just figured out what was causing my AFR to richen and idle to increase after the bike is well warmed up.   It was the vacuum switch that I have read is only on 1985 models, and most forum posts say to ditch it which is what BMW did from 1986 and on.

As soon as I unplugged the vacuum switch the idle returns back to a reasonable number, and the AFR returns to a more normal reading.

Mission accomplished.


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Dave Evans
'Kafe Racer'
kaferacer.wordpress.com

1990 K75RT
1985 K100 Kafe Racer
http://kaferacer.wordpress.com
    

41Back to top Go down    The Final Product on Sat Mar 14, 2015 2:22 pm

KafeRacer

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The bike is done, all of the paintwork is complete.  Only thing left is to find a local dyno to do some fine tuning of the AFR and Ignition Timing.










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Dave Evans
'Kafe Racer'
kaferacer.wordpress.com

1990 K75RT
1985 K100 Kafe Racer
http://kaferacer.wordpress.com
    

42Back to top Go down    Re: K100 KafeRacer Build on Tue Apr 21, 2015 2:40 pm

KafeRacer

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Well, I have now had several rides on the kafe and decided to move the O2 guage up into the dash area for the time being (at least until I get the fine tuning done).  The bike also developed a rattle/vibration which turned out just be the metal mesh in the radiator shroud which was an easy fix.  I also found a new to me rubber tank gasket that sits on the frame under the tank which I installed yesterday.  The bike seems to be running real strong. I have been very pleased with it so far.






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Dave Evans
'Kafe Racer'
kaferacer.wordpress.com

1990 K75RT
1985 K100 Kafe Racer
http://kaferacer.wordpress.com
    

43Back to top Go down    New Photos on Fri Apr 24, 2015 1:28 pm

KafeRacer

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Some more photos of the completed bike.




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Dave Evans
'Kafe Racer'
kaferacer.wordpress.com

1990 K75RT
1985 K100 Kafe Racer
http://kaferacer.wordpress.com
    

44Back to top Go down    Re: K100 KafeRacer Build on Fri Apr 24, 2015 3:03 pm

Holister

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Great read. Sounds like you've adapted the systems quite well and she's running smooth. Would be good to hear the results from the dyno and what your final FP setting is.
Just some questions, considering you've used a 4V motor.
Why didn't you use a motronic instead of the L-Jet?
What injectors are you using (oem #)?

Very sexy machine all round . Well done.


__________________________________________________
1988 K100RT     VIN No.  0094680
1989 K100RT     VIN No.  0097367 (naked)  
1996 K1100RS   VIN No.  0451808
     Fuel:  95 Octane
Engine Oil: Nulon Full Synthetic 15W50
Gear Box Oil:  Nulon Synthetic 75W90
    

45Back to top Go down    Re: K100 KafeRacer Build on Fri Apr 24, 2015 3:31 pm

KafeRacer

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Kaptain Holister wrote:Great read. Sounds like you've adapted the systems quite well and she's running smooth. Would be good to hear the results from the dyno and what your final FP setting is.
Just some questions, considering you've used a 4V motor.
Why didn't you use a motronic instead of the L-Jet?
What injectors are you using (oem #)?

Very sexy machine all round . Well done.
Thanks,

I started with a 2V L-Jet bike and had all the wire harness with Fuel and Ignition ECU's, the only reason I switched to the 4V engine was because I stumbled across the smashed bike with engine cheap (200) so I figured I would try this combo.  The Motronic ECU and harness was already gone from the smashed bike. I also kind of liked the Idea of trying to see if I could get the odd combo to work.

I also considered the following ECU, but havent had the budget for it, and what I have now seems to work very well.

http://www.bskspeedworks.co.uk/engine-management-package.html

I am using the following injectors and running at 3.5 bar pressure currently.

0-280-150-415EV14 hole60.515.9130.0050.753.5071%BMW 6-2.5l, 3.0l


I am looking to find a dyno, the one shop I found won't let me be there to tune the bike, he wants me to leave him with the bike and a blank check...which wont be happening.

Cheers.


__________________________________________________
Dave Evans
'Kafe Racer'
kaferacer.wordpress.com

1990 K75RT
1985 K100 Kafe Racer
http://kaferacer.wordpress.com
    

46Back to top Go down    Re: K100 KafeRacer Build on Fri Apr 24, 2015 8:15 pm

Comberjohn

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Looks really smart, although you don't half do things the hard way.
Was getting dizzy trying to remember if it was an 8v or 16v as you went along!
Good resource for anyone else going done the same path.
Nice job and still think that having the radiator cowl sets it apart from most other custom jobs. Just would look unfinished without it. Are getting hard to find, though.


__________________________________________________
Life is not a rehearsal.
2010 VFR 1200F DCT 
2010 R1200GS(gone)
1986 K100 Silver(gone)
2012 K1600GT(gone)
1984 K100RT Madison Silver(gone)
1989 K100LT Stratus Grey(gone)
1984 K100 Red(gone)
http://www.johnsdrivingschool.co
    

47Back to top Go down    Re: K100 KafeRacer Build on Fri Apr 24, 2015 10:20 pm

Mossy1200

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Like the air filter. 🆒

yours comes out on a sharper angle than mine what is the leg position like?

    

48Back to top Go down    Re: K100 KafeRacer Build on Fri Apr 24, 2015 10:51 pm

Holister

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@KafeRacer wrote:Does anyone know how an L-Jetronic system is affected by the water temp sensor?
There are 3 stages the L-Jet goes thru while warming up.
Cold Start Enrichment: Only when the starter button is pressed the ECU
increases the injection time considerably after checking the coolant temp. This is to compensate for fuel condensing in the intake chambers and cylinders and not vapourising completely prior to any ignition. If temps are very low ie <0°c, injection times can be doubled by the ECU.
After Start Enrichment: When the starter button is released and the motor is running (>720rpm), The ECU goes into After Start Enrichment mode for around 30 secs. The ecu monitors the coolant temp and increases injection times by 30 to 60%.
Warmup: At this point the ECU monitors air flow and temp and adjusts fuel injection times so as to maintain idle untill the engine reaches operating temperature and the ECU produces a base injection time.


As I have installed a wide-band O2 sensor I can monitor the AFR.  The way it is configured now is as follows:

Bike Idles at 1070 shortly after starting and warm enough to not need choke - AFR hovers at 14.
Bike continues to warm up idle slowly increases to about 1250 after 10 minutes - AFR hovers at 14.
Note:  If I press the start button, it riches the mixture (as notes many places on the forum)  With the starter button pressed the AFR richens to about 12, release button and it goes back to 14.
AFAIK the ECU ignores any further signals from the starter button once the engine is running over 720rpm.

After the bike warms up further there is a distinctive point where idle shoots up from 1250 to 1600, and AFR richens from 14, down to 11.8.  Note: Once this occurs, pressing the starter button no longer richens the AFR. At this point pressing the starter button has no affect on AFR.

I assume this is normal, and just a change in the fuel map after the bikes water temp reaches a certain point.

I am also assuming that if I adjust the AFR to be leaner at operating temp, it will be quite lean before the L-Jet changes to its operating fuel map.  Should I be concerned?  I am assuming not, and that running lean during warm-up will simply result in reaching operating temp faster?
I would guess that your #415 injectors would be producing a reasonably rich mix at 3.5bar so leaning it out would be good but running 'lean' would not be ideal.

I also notice that once the bike is at operating temp the spring tension on the air flow meter has virtually no affect on the AFR at idle. Does the L-jet not look at the air flow meter when the throttle is closed? And simply apply only a fixed amount of fuel?

Just looking for thoughts.


__________________________________________________
1988 K100RT     VIN No.  0094680
1989 K100RT     VIN No.  0097367 (naked)  
1996 K1100RS   VIN No.  0451808
     Fuel:  95 Octane
Engine Oil: Nulon Full Synthetic 15W50
Gear Box Oil:  Nulon Synthetic 75W90
    

49Back to top Go down    Re: K100 KafeRacer Build on Sat Apr 25, 2015 12:33 am

KafeRacer

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@Mossy1200 wrote:Like the air filter. 🆒

yours comes out on a sharper angle than mine what is the leg position like?


Thanks,

First I tried to tuck the filter in close to the frame and have my leg on the outside, but that did not work, so I moved it forward and now my knee fits snugly behind it.  New rearsets should give me all kinds of room when I get around to making some, or biting the bullet on some BSKs.

Cheers.


__________________________________________________
Dave Evans
'Kafe Racer'
kaferacer.wordpress.com

1990 K75RT
1985 K100 Kafe Racer
http://kaferacer.wordpress.com
    

50Back to top Go down    Re: K100 KafeRacer Build on Sat Apr 25, 2015 3:09 am

charlie99

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as I understand it

at idle 


the afm has a bypass path that allows unmetered air to bypass the vane

this is controlled by a threaded plug of sorts and is designed to adjust the mixture at idle within a certain range

the bypass screws on the throttle bodies allow for a adjustable idle speed ....and because they are separate require synchronising  for a swiss sewing machine idle

the afm has a closed value of about 1.61 volts back to the efi computer (under seat ) which determines ...along with the water temperature and the thermistor (air temperature ) on the input of the afm  the relative duty cycle of the injectors (how much fuel per squirt )  this can be changed to make the extra fuel injection balance better with the air flow ...but tricky to do without some form of feedback - meter display

if you are getting a change in idle speed once warmed the idle mix is probably too lean ...and could be adjusted via the afm air bypass screw - slug



whilst cold , and additionally under speed (700 or so revs ) and increasing to  running temperature  the predetermined map for cold start conditions apply , along with an adjustable throttle opening device ie the choke lift bar via cable and electronic enrichment from the switch on the throttle bodies - choke lever

the start switch applies extra fuel above and beyond all the above .......and generally  a totally computer generated start sequence during start conditions  ...some have noted that there is a change in mix by pressing the start switch when running above the magic 700 or so revs

a good indication of fuel mix can be achieved by pressing the start button at temperature and noting the revs change ...or lack of  and to be read into the designed carbon emissions standards and adjusting techniques.
 

hope that helps a little


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'86 K100 RT..#0090401 ..."Gerty" ( Gertrude Von Clickandshift ) --------O%O
    

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