Author Topic: Engine fumbles after 1/2 throttle  (Read 851 times)

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rfrench924

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Engine fumbles after 1/2 throttle
« on: April 20, 2007, 05:27:18 am »
We took the bikes out on there maiden voyage last night. My 1981 CB650c seemed to be running great on the side streets leading up to the thruway. Once on the thruway i noticed after about 1/2 turn on my throttle the engine stuttered and power was lost. If i kept the throttle at around 1/4 turn or so i could increase speed with ok power (I would assume this type of power at 1/4 throttle) but i am missing the other 1/2- 3/4 range. She doesn't run any better with the choke pulled, so i don't think its running to lean. Maybe to rich??? I still haven't had the chance to pull any plugs (we didn't get back till late). I will do this today. Also, it seems to become flooded or maybe fouled out if i do try to open the throttle for a long distance. It won't idle well and performance will completely diminish. New plugs and new wires have been put on. Any ideas to troubleshoot would be excellent!!

Thanks in advance,
Ryan

Offline kuyarico

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Re: Engine fumbles after 1/2 throttle
« Reply #1 on: April 20, 2007, 05:39:53 am »
I would say that you are running rich. Pulling the choke will make it run more rich as well. Without knowing anything about your carbs, I would try adjusting the air screws and leaning it out a bit.

see this in the FAQs: http://www.sohc4.us/forums/index.php?topic=5410.msg2455#msg2455
« Last Edit: April 20, 2007, 05:49:59 am by kuyarico »