Yamaha DT360 engine mystery...

edelweiss

Coast to Coast
I have a Yamaha DT360 (2-stroke) that is not pulling fuel up into the cylinder. When the engine is cold, I choke it, kick it forever and get nothing. When I check the spark plug it's dry. However, when I disconnect the gas line and push gas directly up the carb, she starts in one kick and runs the rest of the day. Does this sound like a air leak in the crank seals? My compression is 120 lbs.

Thanks for any help!

John
 
are you leaving your hand OFF the throrttle when choking ? this you must do. is the carb adjusted to let the engine idle nicely ?
if so,well then it is possible the pathway of fuel to the enricher circut is blocked from picking up fuel..
is the enrichener plunger all in good condition ?
 
.
exactly what do you mean by "push gas into the carb"?

if your compression gauge is accurate, your compression is very low which will also make it hard to draw fuel up from the fuel bowl.

low float level will contribute to the prob also.

bad crank seal won't cause this prob.

yeah, could be plugged or partially blocked idle circuits too.
.
 
it is most likely a enrichener issue big 2 stroke can require a decent shot of raw fuel to start from cold...a trick on some big 500 mxers is to turn on the gas lay the bike way over so it floods over the carb with raw fuel
 
Hi Guys,
Sorry for the delay in my response:

Yes, throttle off when choke is on. It idles very nice once its started. The circuits and plunger should be fine, as it's a brand new carb. And I checked the reeds today they looked great.

Thanks,
John
 
ok try this dfrop the idle a full turn then kick 3-4 times with the enrichener open then it should get enough fuel to start if not it is still an issue with the enrichener not delivering enough fuel
is the plunger lifting fully ?
 
I found the problem... The pilot jet was clogged even though it was a brand new carb. She starts fine now. Thanks for the help everyone! I greatly appreciate the support!
 
Back
Top Bottom