mikes6084 Posted May 10, 2009 Share Posted May 10, 2009 hi i have a 86 yamaha tt600 that runs like a bat out of h*** but if you let it idle or come down to an idle it usual stalls after you have been riding about 10-15 minits weather you ride it hard or just let it idle.the main problem is when it does stall you have to wait about 15 minits before you can start it and it starts in 1 or 2 kicks. when i pull the spark plug it is sooty,carburetor is still cold,still has very good compression,and piston is not stuck in the bore. i have been working on this for a couple weeks and every thing that i see is saying it is too rich like sooty plug after stall and black smoke at and just off idle. but every thing i read about jetting a bike carb says the piolet jet is too lean. i will try almost anything except buy new carbs Link to comment Share on other sites More sharing options...
yamahait Posted May 10, 2009 Share Posted May 10, 2009 hi i have a 86 yamaha tt600 that runs like a bat out of h*** but if you let it idle or come down to an idle it usual stalls after you have been riding about 10-15 minits weather you ride it hard or just let it idle.the main problem is when it does stall you have to wait about 15 minits before you can start it and it starts in 1 or 2 kicks. when i pull the spark plug it is sooty,carburetor is still cold,still has very good compression,and piston is not stuck in the bore. i have been working on this for a couple weeks and every thing that i see is saying it is too rich like sooty plug after stall and black smoke at and just off idle. but every thing i read about jetting a bike carb says the piolet jet is too lean. i will try almost anything except buy new carbs sounds rich to me,try to get choke out and make sure its not sticking on,all symptons seem to point that way. cheers Link to comment Share on other sites More sharing options...
Moderator Airhead Posted May 11, 2009 Moderator Share Posted May 11, 2009 It sounds rich yes, but I wouldnt expect this to cause a cut out and an extended period before it re-starts, is the fuel tank vent blocked or trapped so causing a vacuum, the symptom you are experiencing can be caused by this. Link to comment Share on other sites More sharing options...
Moderator DirtyDT Posted May 11, 2009 Moderator Share Posted May 11, 2009 Witha sooty plug. I would say rich. Is the carb sucking in too much fuel at idle which is killing the engine. I also agree that it could be a vacumm. The compression sucks hard enough at revs but at idle it starves itself. Will it tick over without a fuel cap on it? I had an XT wich had the opposite. ran fine and started from hot but if you left the fuel tap on when cold it would not start. Link to comment Share on other sites More sharing options...
mikes6084 Posted May 11, 2009 Author Share Posted May 11, 2009 ok i leaned out the piolet jet,am going to get a new plug today. i never thought about a vacuum being pulled in the tank. i will pul the cap off and let idle and see what hapens. Link to comment Share on other sites More sharing options...
TylerP Posted May 27, 2009 Share Posted May 27, 2009 Check the intake valve clearance. Other stuff to look at...gas cap venting.....worn float needle/seat......worn needle and/or nozzle......gas in the oil.....air box obstruction.......exhaust obstruction. Link to comment Share on other sites More sharing options...
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