394xp was acting up

[foragefarmer]

I busted out the 394 to cut a big log. It fired up fine but when I leaned on it in the cut it wanted to die. I hit it with the tach and screw driver and noticed it wouldn't turn over about 11800. I ended up tuning it to 11500 and it wouldn't die in the cut. Took it home and tweeked the tune up and down. I noticed it would go above 11800 for a second but then settle back to 11700-11800. And if it was tuned lower than 11700-11800 it wouldn't die in the cut. I now know were the problem was, but I didn't get it straight off. Anyone know straight off what the problem was?

 

[5000+]

Mine is stock and 4 strokes hard at 12,500 runs better closer to 13k. No bogging at all.

 

[foragefarmer]

Mine is stock and 4 strokes hard at 12,500 runs better closer to 13k. No bogging at all.

Yes, so what was the problem with the saw?

 

[Dub11]

When was the last time the cab was rebuilt?

 

[cus_deluxe]

Air filter clogged to beat hell?

 

[danimal]

Damn hoosky coils...or yer chains on backwards.

 

[Simondo]

Il start at the basic end with a restrictive fuel filter ?

 

[foragefarmer]

Ain’t there yet. I was convinced it was the coil. That was an expensive miss diagnosis for an OEM coil. Got a backup now I guess.

 

[smokey7]

I'll vote lose intake block.

 

[cus_deluxe]

Wasp nest in muffler? Haha

 

[5000+]

Spark plug

 

[foragefarmer]

Spark plug

What makes you say that?

 

[Dougbert]

Dirty fuel filter

 

[foragefarmer]

Dirty fuel filter

Nah, It was the spark plug as @5000+ said. Pretty new NGK. Although I mostly mill with the saw but that plug probably had 10-15 tanks on it.

 

[5000+]

What makes you say that?

I've seen similar problems, all with new or almost new bosch or ngk plus.

 

[decableguy2000]

Mine did that and I thought cheap aftermarket coil, installed new OEM, then I rebuilt the carb with no issues since than.

 

[foragefarmer]

I've seen similar problems, all with new or almost new bosch or ngk plus.

I am an NGK fan. 3 pickups, the Gator, and everything else gets NGK eventually. I read someone say Denso for 394's.

 

[5000+]

The original champion plug lasted along time too.

 

[afleetcommand]

Seen them with a wore out throttle cable that won't let it get to full throttle....so folks try to lean them out to get the RPM's.. Create a whole new set of problems.

 

[foragefarmer]

Well, it has a brand new NGK in it right now. We shall see...

That makes two spark plugs that have gone bad in it since I got it. I put a good used Bosch; I had sitting around, in it after getting it and it got the hot restart issue. Then it got the NGK and got the revlimit issue.