[BigJohn]

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Quick recap:



Bike hadn't run in several years when I bought it

Changed plugs, oil and filter, fuel and fuel filter.



Starts and runs (badly) at 5k

Gets really choppy around 3.5k

Stalls below that



But, while holding it a 5k, airbox out, suddenly started getting a spray from the disconnected crankcase breather. Caught fire! Literally able to blow it out. Whew! So I assume the rough running is carb issues, but spurting out the breather? Any ideas what would cause that?



Thanks,

John

 

[sandiegobrass]

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The gas in the oil happens while it is parked. Two things have to not be working correctly: the carb float valves and the fuel pet**** (assuming you do use it).. Fuel drains into the cylinders then into the oil..... (actually another less likely path is the carburator fueltubes that can leak into the plenum)... probably ready for a carb rebuild..

Edit: amusing edit by a moderator made an innocent word into something that now really stands out... crazy...

 

[Keno]

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Big John , first thoughts are if crankcase breather sprayed ---1st- over full crank case due to leaking carbs and churned out when engine spinning or running. (explosive mix of gas and oil in crankcase)You just changed the oil so you should be able to verify level in sight glass.

2nd- combination of fuel and severe blow by at the piston rings venting out the crankcase breather vent. ( carbs. flooding, wet plugs, low compression on one or more cylinders)

After sitting for long period it is likely that the carbs. need at least acleaning and possiblerebuild.

Word of caution, very dangerous to crank or run engine with breathers open or air cleaner removed if any backfire or rough idle isoccurring. With breathers andair cleaner in place you have a closed systemdesigned to smother most misfires orinternal fires. Glad your flare up ended as well as it did. (WHEW!) Good idea when working on fuel related problems to keep a fire extinguisher handy. (yeah, I don't think about ittill I am finished either). :waving:Keno

 

[BigJohn]

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Thanks all, actually glad to know it probably traces back to the carbs, figured on having them redone anyway. Was afraid there was more too it.