So I'm finally ready to get the bike running and riding after completely rebuilding the carbs. I installed a Randakk's kit with #145 Main, 2.0 Needle, & #35 Pilot & did a bench sync. Pilot Screw's set 3 turns out.
Bike fires right up with choke and after a bit would idle fine with the choke off.
As soon as I crack the throttle the bike bogs and dies if I stay on it. No amount of coaxing the throttle slowly will get the bike to rev. I was able to get into the 1/4 throttle - 3/4 throttle range using the choke to get the RPM's up. Once the RPM's are near 1/4 throttle I can release the choke and the bike runs smoothly. I was even able to go for a little ride with one hand on the choke and the other on the clutch to get moving!
Anyone have any suggestions on where to start tuning? I'm not sure if I have enough adjustment in the pilot screw to get over the bog from idle to 1/4.
Carb Tuning - Bogging/Dying Off Idle
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Rustle
- Posts: 11
- Joined: Wed Mar 23, 2022 3:39 pm
- Location: Boise
- Motorcycle: 1981 GL1100 Interstate
Re: Carb Tuning - Bogging/Dying Off Idle
To follow up on this for posterity for anyone experiencing similar issues in the future:
I was able to get the bike to rev with the throttle, there's still a bit of a stumble but it's "ridable" for now.
I checked the original plugs which were a little wet indicating a rich condition. I replaced the spark plugs, just to be sure since the old one's age could not be verified. Up until this point I had been running the carbs completely open with no air filter/airbox installed which I believe could contribute to the vacuum slides(maybe?) not functioning correctly? So I installed the airbox and filter. Per the guidance I received on here and verified I started with 3 turns out. However, I'm at about 2800ft AMSL so obviously a little less O2 available which I believe is contributing to a rich condition.
I set the pilot screws in 1/2 turn at a time until the bog/stumble got better. Currently I have the set screws 1 turn out with some slight hesitation from idle to rev the bike. I will set them at 1/2 turn out and try again. If that doesn't improve it I will drop the pilot jet down one and start back at 2 turns out.
I was able to get the bike to rev with the throttle, there's still a bit of a stumble but it's "ridable" for now.
I checked the original plugs which were a little wet indicating a rich condition. I replaced the spark plugs, just to be sure since the old one's age could not be verified. Up until this point I had been running the carbs completely open with no air filter/airbox installed which I believe could contribute to the vacuum slides(maybe?) not functioning correctly? So I installed the airbox and filter. Per the guidance I received on here and verified I started with 3 turns out. However, I'm at about 2800ft AMSL so obviously a little less O2 available which I believe is contributing to a rich condition.
I set the pilot screws in 1/2 turn at a time until the bog/stumble got better. Currently I have the set screws 1 turn out with some slight hesitation from idle to rev the bike. I will set them at 1/2 turn out and try again. If that doesn't improve it I will drop the pilot jet down one and start back at 2 turns out.