Saw bogs down, but why?

[retoocs555]

Ok, I'm working on a Jonsy 521E and can't figure this one out.

Without the chain installed the saw runs fine and revs up fine. Put the chain on and the saw won't rev at all, barely maintains idle.

The carb is properly adjusted.
The Chainbrake has been removed.
Compression is 150psi.
New clutch.
Removed the muffler, cleaned up any carbon and replaced with a like new muffler.
Clean air filter

What have I missed?

 

[Crofter]

Is chain free to pull by hand on bar?

 

[skwerl]

either the clutch springs are weak/ broken and the centrifical clutch is not disengaging, or the chain is binding in the bar, or both.

 

[Kenskip1]

Johnsy

When was the last time you put a gas filter in this thing?When you put the chain on your engine requires more gas. If the filter is plugged then this will slow the engine down. Just my$.02 Ken

 

[retoocs555]

Is chain free to pull by hand on bar?

Yes, of course.

either the clutch springs are weak/ broken and the centrifical clutch is not disengaging, or the chain is binding in the bar, or both.

Chain is loose and moves freely and easily around the bar when I pull it by hand.

This is a brand new clutch and I've tried 3 good used ones (replaced entire assy. shoes, spider, spring, drum). It acts the same each time with each of the configurations.

When was the last time you put a gas filter in this thing?When you put the chain on your engine requires more gas. If the filter is plugged then this will slow the engine down. Just my$.02 Ken

Brandnew fuel filter.

--

If I had let any of that stuff stump me I might as well give up working on chainsaws now

 

[Husky nut]

sounds like its sucking air...since it happens when you put a bind on it with a chain it could be a bad bearing...

 

[HiOctane]

Looks like a clutch problem.With the engine stopped,can you turn the sprocket freely by hand without the engine turning at same time?If not, clutch,washer between clutch and sprocket or bearing could be at fault.

 

[retoocs555]

sounds like its sucking air...since it happens when you put a bind on it with a chain it could be a bad bearing...

The bearings don't feel loose but based on how it's acting thats pretty much the diagnosis I've narrowed it down to.

I wanted to hear that from a couple other people before I forget the project because it's a decent saw. Not quite worth tearing down to replace a bearing though.

It could be still be something else though...

 

[retoocs555]

Looks like a clutch problem.With the engine stopped,can you turn the sprocket freely by hand without the engine turning at same time?If not, clutch,washer between clutch and sprocket or bearing could be at fault.

New clutch is working properly and assembled as pictured in the Jonsy IPL.

 

[West Texas]

This may sound dumb, but I'd try hitting the throttle a bit with the chain brake on and compare that with how it does with the chain on and the brake off. This at least eliminates the bar and chain from the problem.

 

[retoocs555]

This may sound dumb, but I'd try hitting the throttle a bit with the chain brake on and compare that with how it does with the chain on and the brake off. This at least eliminates the bar and chain from the problem.

Tried that.

I even put a little 14" bar on it to see what would happen and it acted exactly the same.

 

[West Texas]

Well it sounds like you've done everything except take it to the Priest to have it "exorcised". Must really be frustrating.

 

[retoocs555]

Well it sounds like you've done everything except take it to the Priest to have it "exorcised". Must really be frustrating.

You said it :bang:

Add to that the fact that its frickin, yes frickin cold out there (in my work area) :censored:

It's the first time I've actually cracked and asked a "Why is my saw...?" question on here. I generally prefer to pretend like I know the answers to those questions.

It isn't the end of the world, I can use the parts off of it to build a really nice 52E.

 

[Husky nut]

The bearings don't feel loose but based on how it's acting thats pretty much the diagnosis I've narrowed it down to.

I wanted to hear that from a couple other people before I forget the project because it's a decent saw. Not quite worth tearing down to replace a bearing though.

It could be still be something else though...

only thing i can think of is the washer on the clutch is binding it up but if the clutch spins freely with chain removed then the seal or seal and bearing is bad...Only reason for it to do it with the chain on is the tension of the chain pulling the crank off center due to a bad bearingthere for wearing the seal out...