Back fires & misses under load

[ed1581]

I have a YT 6800 that I bought last year,  It starts a little hard, but always starts, but lately it has started backfireing & chugging while under a load.  It seems to get better when I turn off the PTO.  Does anyone have any suggestions?  

Also Where can I get parts?

Who works on them around KC?

[rattosh51]

ed1581,
 Welcome to the Forum. When it can't handle a load, there is usually something up with the carb.
Float needs adjusting, debris in the carb, or you may have a restriction somewhere in the gas line or gas cap. Check to make sure your air filter is clean, but the backfiring and chugging seems to be more carb related. I would suggest taking the carb off and giving it a good cleaning/soaking in some carb cleaner and definitely check out the float. Also, some gas additive in the tank never hurts, like Seafoam. You can get parts through this forum's moderator (see link at top of the forum page) or there are other online places.
 Any place that services small engines should be able to work on them, although most don't even know that Yamaha made a lawn tractor!!

[rattosh51]

Parts

http://www.yamahagenuineparts.com 

http://www.babbittsonline.com/yamaha-motorcycle-parts

http://www.powersportspro.com/pages/OemParts?aribrand=YAM

[YamaDog]

I would try all the easy stuff first. but it sounds like you may have sheared your flywheel key.  I have seen this on other motors.  Will throw your timing off.

[ed1581]

Thanks even though it runs great for a while?

[YamaDog]

If it runs good for a while it will not be that.  You might check and make sure the air flow thru the motor and  is not clogged up with grass or something. when a engine get hot it will backfire and loose power.  My yt3600 has a shroud around the engine and the flywheel sucks air in over the engine and out the front around the muffler,