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Had an issue at the weekend on my 1989 Suzuki RM250, fitted with a Lectron Carb
I've had the Lectron for a while now and I am happy with the rod and 'main jet screw' settings. Plug is a dark tan colour and bike pulls clean throught the RPM range.
First 2 races at the weekend were great, bike ran well other than being a real pig to start from cold and cant get a good warm engine temp idle.
Then race 3 it all of a sudden went lean, when slowly building the revs the bike now takes off and zips up to a high RPM at about 1/4 throttle.
Everything seems fine, cant spot any leaks and cant see any obvious dirt etc in the carb.
Any ideas as to what this may be?
Carb related or possible air leak somewhere?
I've had the Lectron for a while now and I am happy with the rod and 'main jet screw' settings. Plug is a dark tan colour and bike pulls clean throught the RPM range.
First 2 races at the weekend were great, bike ran well other than being a real pig to start from cold and cant get a good warm engine temp idle.
Then race 3 it all of a sudden went lean, when slowly building the revs the bike now takes off and zips up to a high RPM at about 1/4 throttle.
Everything seems fine, cant spot any leaks and cant see any obvious dirt etc in the carb.
Any ideas as to what this may be?
Carb related or possible air leak somewhere?
Carb was purchased new less than a year ago so is still pretty immaculate, but I'll drop it in my ultrasonic cleaner to ensure there's nothing got stuck in it.
Engine has 4.2 hours on it since a complete overhaul. Crank split, all bearings and seals done. My engine builder is like a surgeon and extremely methodical/picky with his work. Engine was leak down tested after the rebuild.
I'd like to think its not a crank seal but I will investigate.
I'll give the airbox/airboots a thorough inspection tonight. I think I'll re do the air boot to air box connection to eliminate that possibility if I cant find any obvious cracks etc
The Shop
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