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1Back to top Go down   K100 dies after hot fast run Empty K100 dies after hot fast run on Fri Aug 30, 2013 7:04 am

Edmate

Edmate
active member
active member
Dear All
help please.  My 1984 k100 has a bad habit of dying on the freeway.  
Here are the contributory factors:
1. ambient temp over 25 degrees C
2. Hot run over 20 minutes including 5 minutes over 5000 revs
3.  Fuel tank down to 5 litres (ish)

Symptoms:
a.  Uneven revs on steady throttle then engine dies as I pull to a halt.
b.  wait for a couple of minutes and will restart on choke!
c.  dies again regularly until allowed to properly cool down.

Other information:
i.  running on 98 unleaded
ii. previously solved problem by upgrading fuel grade to 98 and running some injector cleaner through system but it comes back when conditions above occur.
iii. the bike has done this consistently since I bought it  10 months and 240000kms ago.


Any ideas?
edmate

    

2Back to top Go down   K100 dies after hot fast run Empty Re: K100 dies after hot fast run on Fri Aug 30, 2013 7:32 am

92KK 84WW Olaf

92KK 84WW Olaf
Life time member
Life time member
Hall sensors?

Not picking up the last 5 litres of fuel in the tank due to filter or positioning of pick up?

A frustrating problem but unlikely to be an expensive on I think.


__________________________________________________
1992 K100LT 0193214 Bertha Alaska Blue 101,000 miles
1984 K100RT 0022575 Brutus Baja Red bought 36,000 now 89,150 miles
1997 K1100LT 0188024 Wotan Mystic Red 58,645 now 98,780 miles
1983 K100RS 0011171 Fricka 29,495 miles Damn K Pox Its a Bat outta Hell No 32,600 miles
    

3Back to top Go down   K100 dies after hot fast run Empty Re: K100 dies after hot fast run on Fri Aug 30, 2013 7:45 am

RicK G

RicK G
VIP
VIP
Doesn't quite meet the Hall sensor caper I think. They usually are very definitive about not restarting till cold.
Try a new fuel filter as the injector cleaner will clear some of the crud from the filter and let it run for a bit longer.
Could be the fuel pump I have seen similar symptoms from one when it was dying.  To me it sounds like a fuel problem.


__________________________________________________
"Man sacrifices his health in order to make money.
Then he sacrifices money to recuperate his health.
And then he is so anxious about the future that he does not enjoy the present; the result being that he does not live in the present or the future; he lives as if he is never going to die, and then dies having never really lived."   Dalai Lama


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

4Back to top Go down   K100 dies after hot fast run Empty Re: K100 dies after hot fast run on Fri Aug 30, 2013 7:57 am

AL-58

AL-58
Life time member
Life time member
Fuel in the tank getting too hot and vapour lock, lack of insulation under the tank.  If you can feel your fuel rail, how hot is it getting.  Has it only just started doing this or you've only just discovered it?

I had an 85 that did this on a regular basis, but not as low as 25C.  The other factors were the same though, low fuel and hard running

Al


__________________________________________________
'87 K100RS/HRD sidecar (1100 motor)  sc25 
'92 K100RS-16v (Paint it Black)

'87 K100RT with Paralever backend

"When I'm too old and too foolish to handle a sidecar I'll buy a Sportsbike"

K100 dies after hot fast run K-dogs10
    

5Back to top Go down   K100 dies after hot fast run Empty Re: K100 dies after hot fast run on Fri Aug 30, 2013 8:27 am

Guest

avatar
Guest
If you decide it's the hall effects, I have a 2nd hand plate here from motorworks that I didn't use.

    

6Back to top Go down   K100 dies after hot fast run Empty Re: K100 dies after hot fast run on Fri Aug 30, 2013 10:19 am

Lazyboy

Lazyboy
Silver member
Silver member
I have to agree with AL-56 . My 84 K100RT left me standing on the side of the road many a time on a hot day +28c The fuel would start to perculate in the tank and I would have to waite 10 minutes for it to cool down Started the problem once the fuel level was less than half. Fitted a small oil radiator from a Jap bike to the fuel return line to the tank and that was the end of my problem. Do a search of the forum and you will find my article together with a lot of other members ideas.
Lazyboy


__________________________________________________
1984 BMW K100RT

Bikes Name: Lazyboy
    

7Back to top Go down   K100 dies after hot fast run Empty Re: K100 dies after hot fast run on Fri Aug 30, 2013 9:25 pm

RicK G

RicK G
VIP
VIP
I fitted a fuel cooler to my K1100 a short while ago and the temperature of the fuel in the tank is considerably lower.  Mine was so bad that I would get a huge heat rash on my inner thighs, I fitted knee pads which stopped the rash but not the hot tank.


__________________________________________________
"Man sacrifices his health in order to make money.
Then he sacrifices money to recuperate his health.
And then he is so anxious about the future that he does not enjoy the present; the result being that he does not live in the present or the future; he lives as if he is never going to die, and then dies having never really lived."   Dalai Lama


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

8Back to top Go down   K100 dies after hot fast run Empty Re: K100 dies after hot fast run on Mon Sep 02, 2013 6:59 pm

sidecar paul

sidecar paul
Life time member
Life time member
I've had the same problem with my outfit 3 times in the last 5 years. I thought I had cured it when I cleaned and tightened the plug that powers the fuel pump but It happened again only last week on a trip up to Yorkshire.
I'm not sure of the fuel levels each time, but it was fairly low on the last occasion with about 3 litres left.
Each time the ambient temperature was never very high...well it is the UK!

I'll be watching this thread in the hope that someone finds a definitive answer, but, as with all intermittent faults, all I can do is clean various contacts, not knowing if the problem will recur or not.

Paul.


__________________________________________________
'84 K100RS (0014643) (owned since '85), 86 K100RS (0018891) with Martello sidecar (built as an outfit in '88),
'51 Vincent (since '67),'72 Montesa Cota (from new), '87 Honda RS125R NF4 (bought 2015) 
....No CARS never ever!
    

9Back to top Go down   K100 dies after hot fast run Empty Re: K100 dies after hot fast run on Mon Sep 02, 2013 7:10 pm

92KK 84WW Olaf

92KK 84WW Olaf
Life time member
Life time member
I was doing some work on the RT at the weekend.

I had noticed that the tank was getting extremely hot at the rear by comparison with the LT. When I had the tank off I noticed the air baffles were not correctly in place and in fact were directing hot air up under the tank instead of blocking it. There is a left to right baffle across the intake plenum and air filter that closes off this air passage forcing hot air out the side vents instead of allowing it to travel back under the tank and heat up the rear part. Make sure this is correctly in place.

Secondly there is also a plastic deflector plate under the frame tubes, above the radiator/intake plenum that comes back as far as this air baffle, this stops hot air getting up to the tank and also protects the wiring from excess heat.

Third point is there is a protective insulating sleeve over the fuel rail return pipe........don't be tempted to leave it off.


__________________________________________________
1992 K100LT 0193214 Bertha Alaska Blue 101,000 miles
1984 K100RT 0022575 Brutus Baja Red bought 36,000 now 89,150 miles
1997 K1100LT 0188024 Wotan Mystic Red 58,645 now 98,780 miles
1983 K100RS 0011171 Fricka 29,495 miles Damn K Pox Its a Bat outta Hell No 32,600 miles
    

10Back to top Go down   K100 dies after hot fast run Empty Re: K100 dies after hot fast run on Tue Sep 03, 2013 12:02 am

AuntieBB

AuntieBB
Silver member
Silver member
@Edmate wrote:..... the bike has done this consistently since I bought it  10 months and 240000kms ago.
affraid  holy crap! you've done 240,000km in 10 months? That's 6,000k a week.

I think the problems are just your bike indicating it wants a bit of a rest Very Happy

When was the last time you replaced the fuel filter?


__________________________________________________
once upon a time: 1987 K100RT/TIC
now: 2010 R1200GS
    

11Back to top Go down   K100 dies after hot fast run Empty Re: K100 dies after hot fast run on Tue Sep 03, 2013 1:13 am

Shep

Shep
Silver member
Silver member
First and foremost I have limited experience in maintaining these bikes. However my ride is 1987 K100RS and my recent acquisition is a 1985 K100RS that is missing a few things including the gas cap assembly. Somewhere on the internet I was told not to buy the original gas cap but to purchase a newer style. I was told that the original 1985 gas cap was prone to causing vapour lock under certain conditions and the later version corrected that by properly venting the tank.
In my research for a replacement gas cap this was the information from a dealer/wrecker "The 1984 & 1985 K100, RS, & RT had a push-button cap that was well known for vapor-locking. I probably have one lying around if you are searching for the OEM cap they left the factory with. I recommend against using the old style, but if you have to have it, call the shop and we can set you up.I also found on the internet the following " '85 models... * got a revised final drive breather vent * had the spring removed from the fuel tank check valve (due to noise) Mid-1985 models got: * a flange on the end of the engine output shaft, while earlier models had locating circlips. * springloaded fuel cap instead of pushbutton style"
Best of luck to you

Shep

    

12Back to top Go down   K100 dies after hot fast run Empty Died again tonight! on Tue Sep 10, 2013 7:31 am

Edmate

Edmate
active member
active member
Dear All
The bike died again tonight on the way home, under all the usual circumstances, it being a 30 degree day, the tank almost empty and within 2 k's of my usual stopping point.  At least it is consistent and it was still faster than the train.  The problem first occurred the week I bought it and has occurred several times since but not over the winter months but now things are warming up it's back with a vengeance..
Thank you for your suggestions as a result of what you have said I will be:

  1. putting in a new fuel filter ASAP (last one went in 25,000kms ago)
  2. checking out fuel pump prices 
  3. checking the fuel rail heat- my engine is getting extra hot at the moment-I was going to flush the radiator and replace the thermostat as well.
  4. studying the fuel return oil radiator option on the fuel return line
  5. Checking my air baffle positions and
  6. getting hold of a new fuel cap
  7. reading up about Hall sensors

I'll be doing 1, 3, 5 first, then 6 followed by 2 and 4, based on the "do the simplest and cheapest first" and see how it goes. 
I am also going to take the "Old Road" on hot evenings.  I am also going to look into buying a stand in bike whilst I sort out the old girl. but I need something cheap cheerful and reliable for less than AU $4k that will not add to my woes.  For example does anyone have an opinion about  the  1994 model K1100RS on BikePoint for $4000? 
 I don't mind living with the occasional stop by the road, it's part of riding an old bike, but I'd prefer to break down as a hobby on a Sunday, rather than professionally during the week
 Thanks again excellent advice every body I'll keep you posted
Edmate

By the way it was only 25000km not 250000 - fat finger syndrome and my rear drive gearbox oil was creamy when I changed it yesterday - after 25,000 k's somethings leaking!

    

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