Misfire under load. 85 FLHTC
Misfire under load. 85 FLHTC
Hey guys haven't posted much here before. I can usually find what I need by searching previous post. I need advice and opinions.
I have a 1985 FLHTC all stock. It fires up and idles well. I can rev the engine and everything sounds fine. When I get it out on the street and put the bike under a load it starts spitting and sputtering and tries to die out. I can pump the throttle and keep it going and suddenly it will take off and accelerate, but when I shift gears the same thing happens. If I don't pump the throttle it will just die.
It started a while back. We went for a ride. After my first fill up it started doing it. We left the group and started heading back when all of a sudden it backfired through the carb and then started running perfect. figured I just had some water in the gas or something and caught back up with the group and it ran perfect the rest of the day. After that day it did it a few more times and now does it always.
I have changed the spark plugs, spark plug wires, new gas, took the carb off and cleaned it. Not sure what else I should try. Please help. I hope this makes sense, if not, ask and I will try to answer any questions as best I can. Thanks guys!
I have a 1985 FLHTC all stock. It fires up and idles well. I can rev the engine and everything sounds fine. When I get it out on the street and put the bike under a load it starts spitting and sputtering and tries to die out. I can pump the throttle and keep it going and suddenly it will take off and accelerate, but when I shift gears the same thing happens. If I don't pump the throttle it will just die.
It started a while back. We went for a ride. After my first fill up it started doing it. We left the group and started heading back when all of a sudden it backfired through the carb and then started running perfect. figured I just had some water in the gas or something and caught back up with the group and it ran perfect the rest of the day. After that day it did it a few more times and now does it always.
I have changed the spark plugs, spark plug wires, new gas, took the carb off and cleaned it. Not sure what else I should try. Please help. I hope this makes sense, if not, ask and I will try to answer any questions as best I can. Thanks guys!
I did. I even took it off and checked to make sure it was working. Good guess though. Great ideas so far please keep them coming. I hope to fix it by valentines day. I am taking off work and taking my wife out. I hope to take the bike.
Road Master
Joined: Jan 2012
Posts: 856
Likes: 9
From: North Carolina
I have heard that 1985 models needed an ignition every few years. Might check that. I don't think they are all that expensive. The normal symptom is that they run normally till the everything gets warm then they shut down or run poorly. Might be worth it to check that when the engine is at opperating temp. If it's not fuel it's gotta be spark.
Last edited by falconbrother; Feb 9, 2013 at 09:34 PM.
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Dirt don't hurt
Joined: Jan 2011
Posts: 21,065
Likes: 4,561
From: Haslet Texas
Have you run a compression test on the motor?
Coughing through the carb could be a rich setting. What do your plugs look like?
Coughing through the carb could be a rich setting. What do your plugs look like?
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Seasoned HDF Member
Joined: Mar 2012
Posts: 100,455
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From: Centennial, CO
Wild *** guess- Coil going bad? Have had it happen in a car. Still running a points ignition? Plenty of electrical things that get spotty with age that will allow a vehicle to idle properly but cause trouble under load.
I have changed the coils no different. I have checked the plugs and it is not running rich. I have not checked compression or the ignition. Is there a way to check the ignition without just replacing it? Also, what should the compression be and are you supposed to check compression with the engine warm?