yukonerdave
New member
Hello
New to this forum and I'm looking for some help diagnosing an issue with my 1997 BF15. The motor runs great 90% of the time but every once in a while I get a hard stutter at start-up, or when coming down from an open throttle. Occasionally it will also happen while putting along at low RPM. It never happens at mid-high RPM. It will often last 5-10 minutes while I try restarting. When it is stuttering it is unresponsive to opening the throttle, except that it will die if I open it too much. Eventually, whatever is causing it will become unstuck and the engine will rev up normally again.
I've replaced the fuel tank, all the hoses, and the filter, and ultrasonic-cleaned the carburetor thinking that dirty fuel was causing a partial blockage, maybe in the carb. The carb is whistle-clean now but I get the same issue. I am starting to think it must be a stuck valve or intake port. I ran some fuel additive through and a valve cleaner product to the crankcase. Didn't help.
I'll add links to 3 videos; one showing the stutter problem, one showing it operating great at high throttle, and another showing it idling properly at low throttle.
I'd really appreciate any thoughts on what is causing the stutter and how to fix it; it is frequent enough that I don't trust the motor to get me home.
https://photos.app.goo.gl/XG29MZfTCA9475248
Thanks a ton
Dave
New to this forum and I'm looking for some help diagnosing an issue with my 1997 BF15. The motor runs great 90% of the time but every once in a while I get a hard stutter at start-up, or when coming down from an open throttle. Occasionally it will also happen while putting along at low RPM. It never happens at mid-high RPM. It will often last 5-10 minutes while I try restarting. When it is stuttering it is unresponsive to opening the throttle, except that it will die if I open it too much. Eventually, whatever is causing it will become unstuck and the engine will rev up normally again.
I've replaced the fuel tank, all the hoses, and the filter, and ultrasonic-cleaned the carburetor thinking that dirty fuel was causing a partial blockage, maybe in the carb. The carb is whistle-clean now but I get the same issue. I am starting to think it must be a stuck valve or intake port. I ran some fuel additive through and a valve cleaner product to the crankcase. Didn't help.
I'll add links to 3 videos; one showing the stutter problem, one showing it operating great at high throttle, and another showing it idling properly at low throttle.
I'd really appreciate any thoughts on what is causing the stutter and how to fix it; it is frequent enough that I don't trust the motor to get me home.
https://photos.app.goo.gl/XG29MZfTCA9475248
Thanks a ton
Dave