stihl ms291 help please

[Brian Carlson]

Well took this saw in for a friend. It wasn't running well when put on its side after it warmed up. Replaced fuel line and carb cause I can't figure out how to bypasss the limiters. Still ran bad so replaced tank vent. It didn't help and actually got worse. I built this saw a year ago because his workers straight gased it so I thought maybe it had developed an air leak. Replaced the crank seals and resealed the clamshell. Installed a new intake manifold. The thing will still not run right. Will not respond to carb tuning. It will fire on choke but won't take throttle to high rpms. If I richen the screws it gets a little better but still won't run. Funny thing is the inside of the engine when I tore it down was saturated with fuel like it was flooding. It has no muffler screen in it. I am stumped. Could it be loosing spark after it fires? I am almost to the point of taking a big hit on the new parts and giving it back with a big apology. If anybody has any ideas I am all ears.

 

[a. palmer jr.]

You might be down to just going through the basics, check compression, spark, fuel system. Might do a pressure/vac test on the engine if you have the equipment. On a couple of my saws a cheapo Chinese carburetor fixed it. Lots of possibilities.

 

[nitehawk55]

If it's flooding out I would suspect the metering setting for a start . Something up with the carb I think .

 

[Brian Carlson]

Well I am down to buying another carb and trying it. If that don't get it I am letting him have it back and I am through. I have been through everything. It will fire on choke. Go to half choke.and.it.Will hit and rev then die. I hate these new limiters on this epa crap.