BMW K bikes (Bricks)


You are not connected. Please login or register

View previous topic View next topic Go down  Message [Page 1 of 1]


1Back to top Go down    Timing Off??? on Wed Jul 20, 2016 7:38 pm

robdiaz44

avatar
active member
active member
Hey all...I've got an '85 K100rs. I took a picture (using the reflection in a mirror) behind the Hall Effect Sensor...all the posts I've read talk about the notch on that circular plate lining up with the TDC marker. This is WAY off. Am I in some serious trouble here? Recent service in the last few weeks: new fuel filter, fuel lines, Fuel Pressure Regulator, vacuum line and caps. When I started the bike back up, it was idling really rough and would often times cut out if I did not have the "throttle advance" (choke) engaged. Weird thing is, prior to recent service, the bike idled okay...it was just bogging down on me when I opened the throttle to about 2500 to 3000rpm's.

    

2Back to top Go down    Re: Timing Off??? on Wed Jul 20, 2016 9:53 pm

KJustin

avatar
Silver member
Silver member
It would be easier to tell whether you are close if you posted a picture with the HES plate installed. In the interim, I'll try to explain what I remember from doing a HES replacement a few months ago.

The plate holding the sensors has notch on it. Measuring, as a guess, about 5/16" at its widest point. There is a corresponding notch on the engine block that the sensor plate notch lines up with. The notch on the block is, as you face the front of the bike, looking at it from the front wheel towards the engine block on the right, probably at about a 3 o'clock position. When you put the HES plate back in, the two notches need to line up (as a starting point) creating a hole that you can stick the tip of your little finger into. They will be exactly the same size. From there, you can tweak the timing a little bit by rotating the plate a hair or two (technical term) to advance or retard the timing to get different firing/performance characteristics. There's a good thread elsewhere on the forum about finding the "sweet spot" on timing (sounds like you may have seen that thread).

I think this link will show a picture of what I'm trying to describe with the plate installed: http://www.servimg.com/image_preview.php?i=105&u=17702881

Hope this helps. Good luck!


__________________________________________________
1985 K100 Cafe Racer (formerly an RT), VIN 0051736
    

3Back to top Go down    Re: Timing Off??? on Wed Jul 20, 2016 10:10 pm

Holister

avatar
Life time member
Life time member
The notch should align with the TDC marker when cylinder #1 is at top dead centre. I'd guess that's going to be ok.
The timing plate which you've removed should be installed correctly with the crescent washers underneath and positioned like the photo below.

If its still not running right there could be some other issues.
HT leads may be mixed up. (sounds likely)
Spark plugs
Temp sensor
Fuel injection issues.

Cheers


__________________________________________________
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
    

4Back to top Go down    Re: Timing Off??? on Wed Jul 20, 2016 10:16 pm

KJustin

avatar
Silver member
Silver member
That's the same picture I tried (unsuccessfully) to post. Thanks, Hollister!

The list of other things to check is right on as well. I'd also add that you should also check and clean (with Deoxit) the ICU plug (under the tank, near the headstock). And also be sure that the clean plug is firmly and totally seated. I've had problems with this twice now and it caused all sorts of strange and incredibly frustrating problems.


__________________________________________________
1985 K100 Cafe Racer (formerly an RT), VIN 0051736
    

5Back to top Go down    Re: Timing Off??? on Thu Jul 21, 2016 12:08 am

robdiaz44

avatar
active member
active member
Thanks guys. So, what you're saying Holister is that if my Cylinder #1 is not Top Dead Center, the notches (ones I referred to in my picture) will not necessarily line up.?.? Before I took the HES off, I did notice that it did resemble the one in your picture...crescent washers were where they should be...and the HES timing plate was situated like the one in the your picture.

Justin, I have recently "Deoxited" all electrical contacts, including the frustrating under the tank connector...I did notice that 2 of the 4 male connectors (the ones actually attached to the tank) were a bit darker than the other 2. I dousedthe male side connectorwith Deoxit and used some very fine sandpaper and toothbrushto try to get as much of the oxidization/crud off. The fuel pump has no issues running...though I imaginea pressure test would be good to do. Also, I will make double sure that it is totally seated.


My next venture was to change spark plugs and wires - existing wires are connected correctly to their respective coil connections, but cylinder 1 plug wire had a small gash in itabout and inch from the "boot"...and, when I checked it, was not seated completely on the plug. Unfortunately, when I snapped in on, the bike still didn't start. I also have on my list to have the injectors cleaned/refurbished.

    

6Back to top Go down    Re: Timing Off??? on Thu Jul 21, 2016 1:22 am

Holister

avatar
Life time member
Life time member
if my Cylinder #1 is not Top Dead Center, the notches (ones I referred to in my picture) will not necessarily line up.?.?

Correct. In fact they won't line up. That mechanism in there is the basis for your ignition timing as well as your valve timing. When Cyl #1 is at TDC on compression, that plate behind the rotor must line up with the TDC mark on the casing.
There's no reason to believe that yours is mis-aligned unless someone has taken it apart recently. In any case, if it was out by that much as in your pic (90o)... the engine would not run at all.

If you want to check for TDC, remove the SPs and stick a length of brazing rod or similar in #1 to determine the highest point of the cylinder as you gently wind the motor over by hand. MAKE SURE THE IGNITION KEY IS OFF.

Or... Just reinstall the timing plate as shown and troubleshoot elsewhere. Timing is never a problem with these bikes. Its 'set and forget'. You can advance the timing plate 3 or 4 degrees (counter clockwise) but that's about it.

Re: the split in your SP lead.... that could well be your problem. You can get a new set of oem leads from Motorworks in UK or NKG leads from EME in the US.

EDIT: I just noticed...You didn't mention in your OP that your bike wouldn't start... That's significant. Go to the Portal Tab and click the troubleshooting link. You'll find a flowchart there which is very helpful plus a lot of other useful information.

I flipped the photo the right way round



Last edited by Holister on Sat Jul 23, 2016 9:55 am; edited 1 time in total (Reason for editing : correction)


__________________________________________________
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
    

7Back to top Go down    Re: Timing Off??? on Thu Jul 21, 2016 1:50 pm

KJustin

avatar
Silver member
Silver member
"Or... Just reinstall the timing plate as shown and troubleshoot elsewhere."

This is what I did, without finding TDC.

If you are interested, I have a set of OEM plug leads, removed from my 1985 K100RT. I replaced them with the NKG ones from EME thinking that the leads were the problem. Turns out that my problem was actually the ICU plug, and maybe a failing coil. I believe that the plug leads I removed are good, however. If interested, PM we and we can discuss price, etc.


__________________________________________________
1985 K100 Cafe Racer (formerly an RT), VIN 0051736
    

8Back to top Go down    Re: Timing Off??? on Fri Jul 22, 2016 12:51 pm

robdiaz44

avatar
active member
active member
Thanks Justin...I may get to you on the plug wire offer.

    

9Back to top Go down    Re: Timing Off??? on Sat Jul 23, 2016 3:59 am

k-rider

avatar
Life time member
Life time member
You can advance the timing plate 3 or 4 degrees (counter clockwise)


Kaptain: i believe that to advance the ignition, you have to rotate the hes plate
CLOCKWISE when looking at it. Laughing


K-rider


10Back to top Go down    Re: Timing Off??? on Sat Jul 23, 2016 9:53 am

Holister

avatar
Life time member
Life time member
Hey k-rider. Thanks for the correction. Clockwise it is. Cheers


__________________________________________________
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
    

Sponsored content


    

View previous topic View next topic Back to top  Message [Page 1 of 1]

Permissions in this forum:
You cannot reply to topics in this forum