engine stumbles at 2k rpms-help

[K1100LT]

1995 k1100lt 40k miles engine stumbles like no fuel at times(it has fuel) it idles fine. checked fuel filter and hoses for crackes-none HELP!

[James.A]

Check the newest thread on "airheads". Similar problem discussed. General consensus leaning toward secondary ignition trouble.

[deilenberger]

1995 k1100lt 40k miles engine stumbles like no fuel at times(it has fuel) it idles fine. checked fuel filter and hoses for crackes-none HELP!

Need more information.

Does the stumble clear up above 2k? If so - where?

When is the last time the plugs were changed?

Does it do it ALL the time (this isn't an intermittent problem)?

[barryg]

fuel filter my be stopped up.

[CARVERBOATBOY]

Very interested in this thread I have a 1986 K100 RT with the same trouble. Just took it to the dealer for a tune up hoping this would fix the problem no luck. This stumble or loss of power occurs in any gear and any temp around 2500 - 3000 RPM could be happening at higher RPM's but is not noticeable. The dealer suggested changing plug wires as this is the only thing they did not try, but at $40 + per wire I would be interested in any comments from the knowledgeable folk here first.

Jeff

[roy]

Very interested in this thread I have a 1986 K100 RT with the same trouble. Just took it to the dealer for a tune up hoping this would fix the problem no luck. This stumble or loss of power occurs in any gear and any temp around 2500 - 3000 RPM could be happening at higher RPM's but is not noticeable. The dealer suggested changing plug wires as this is the only thing they did not try, but at $40 + per wire I would be interested in any comments from the knowledgeable folk here first.

Jeff

Jeff, I don't know if this will help but my 85 K100 had this problem at around 4700-5000 RPM. Turned out the root cause was a dirty connection on the throttle position sensor connection. Wire clip retainer is pain on this connector but might be worth the time to check this out.

Option two: Two much alcohol :drink in the gas :D


Roy

[CARVERBOATBOY]

Thanks for the info ...cleaned the contacts no change .... Stuck a crowbar in the wallet and ordered the plug wires today....

[K1100LT]

the problem is intermittent, fuel filter replaced 7,000 miles ago. I have just started to work on it and found some crankcase vent tubes cracked and leaking(parts on order) but I also found the positive battery cable was loose slightly :doh and that may have been the problem? Waiting for parts be for I can test. Thanks again for the advice.

[bmwmick]

the problem is intermittent, fuel filter replaced 7,000 miles ago. I have just started to work on it and found some crankcase vent tubes cracked and leaking(parts on order) but I also found the positive battery cable was loose slightly :doh and that may have been the problem? Waiting for parts be for I can test. Thanks again for the advice.

The TPS is also suspect but your low mileage puzzles me. On my '93 K1100LT, the TPS had a very definite dead spot in it and would falter right about 4,500-5,000RPM. Once I replaced it, I tore into the old one and found one of the carbon traces inside had a wear mark on it. I'm guessing it spent so much time at that RPM range that it wore thin and caused my problem. Mine failed at about 95K miles if I recall correctly without looking up my records. Frank Warner has a good write-up on the TPS here:
http://www.geocities.com/fwarner_au/mc_things/K_fuel_injection.html

[deilenberger]

Very interested in this thread I have a 1986 K100 RT with the same trouble. Just took it to the dealer for a tune up hoping this would fix the problem no luck. This stumble or loss of power occurs in any gear and any temp around 2500 - 3000 RPM could be happening at higher RPM's but is not noticeable. The dealer suggested changing plug wires as this is the only thing they did not try, but at $40 + per wire I would be interested in any comments from the knowledgeable folk here first.

Jeff

Sorry to see you ordered the wires. They rarely fail - and it's a snap to test them. You need a Volt-Ohm-Meter (VOM) - about $15 at Radio Shack (they have a nice tiny digital one for $15 that I carry on my K..)

The plug wires should measure 5K Ohms (5,000 Ohms) +/- 10% (most good ones fall within 2-3%). If they read more than 6,000 Ohms - they're shot.

HTH,

[deilenberger]

the problem is intermittent, fuel filter replaced 7,000 miles ago. I have just started to work on it and found some crankcase vent tubes cracked and leaking(parts on order) but I also found the positive battery cable was loose slightly :doh and that may have been the problem? Waiting for parts be for I can test. Thanks again for the advice.

Sounds like you may have found at least a few good possibilities..

One note - mileage on a fuel filter isn't an indicator of good/bad. If you always get good quality fuel - the filter may last the life of the bike (if anyone has found out what that is on a K bike.) If you have one tank of bad gas - the new filter you put in may plug up in 50 miles if you haven't cleaned out the bad gas.

A spare filter is one part I carry on the bike (and a spare clutch cable..) - fits nicely in the tail-pod.