Is my 250 dead?

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jackjcc

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So I'd been having some issues with my 250, mainly that it would die as it returned to idle unless I blipped the throttle on the way down. It was just annoying, fiddled with the carb and nothing. Checked the bar sprocket, nope not binding and no burs or anything on the bar. Then I finally notice a lot of bar oil in places it shouldn't be so I take the clutch cover off and it looks bad. Had black oily residue coming from around the clutch.

parureje.jpg


Seems most of the clutch is covered in black crud, almost like carbon build up in a gun. So I inspect the clutch and drum and I see a 1/4" tall 1/8" thick black band of the carbon like residue on the inside of the drum and it took a pliers to scrape it off.

e8udy6ut.jpg


Seems like it got a bit warm...

qe7e8y4u.jpg


Notice the pliers in the background, that is what I scraped off the inside. So my theory now is that the clutch is holding on to the drum longer than it should, which puts load on the engine as it is throttling down and kills it. If I blip the throttle on the way down it gives a little more time for the clutch to disengage and then the saw will idle normal. Is my thinking pretty straight here? It felt like an epiphany that just made sense, but Im no expert, just logical deduction.

So now I go to figure out why the oil is all over the clutch, I figure it's not leaking from the oiler, because oil doesn't leak out when it's sitting with oil in the tank. I see it as soon as I look at the oil to bar transfer slot...

2u8utu7u.jpg


It goes clean through and I have no idea how that happened...really puzzled and still I feel like there should be metal plates there, but I'm told there isn't.

Basically I want to know if I can epoxy that crack so I can go back to using this saw. To me that seems like the only option other than getting a new case. Thanks for hearing me out, guys.
 
Im thinking the reason you have to bring the RPM's down nice and easy for it to accept Idle is because of an air leak, (assuming you carb is working properly) I experienced this the other day.
I would pressure/vac test the saw.
The clutch look like it has been hot a few time, check to make sure your clutch spring aren't getting sloppy also.

As far as the mess of bar oil every where its probably from you feathering the throttle all the time to bring the saw back to idle.
 
looks like the chain jumped out of bar groove and carved at the case. i can't tell you whether it has bar spacers but it should have at least an inner to prevent that problem. i would clean it up real good and epoxy it for the hell of it. you have nothing to lose really.
 
Thanks for the thoughts guys, there's not really any other evidence that indicates air leak, but I would do a pressure test if I had the ability. I've yet to get together a pressure tester.

At what point can you say the clutch or springs are too worn? Is there a set gap between the shoes and the drum and once the resting clutch is closer than that distance it needs to be replaced?
 
You'll know when the clutch springs are worn when you can't idle the saw without the chain moving.
 
The chain does rest at idle. After I get the drum degreased and the bar oil slot fixed I'll have to check on it again. If I wanted to pressure test it by using inner tube rubber between the jug and the muffler would that work? I don't have a piece of aluminium that i could cut to fit the exhaust?

I'm sure I can rig up a low pressure test with an air comp and remove the valve in my pressure tester. I'd at least get a constant pressure to check the critical areas for leaks.
 
Thanks for the thoughts guys, there's not really any other evidence that indicates air leak,
That is what I thought till I hook up the Mityvac to the saw, It acted normal except it wouldn't return to idle with out stalling.

Yes sandwich a piece of inter tube between the muffler and the carb, no need for fancy block off plates if your only doing a few here and there.

Let us know what you find, good luck.
 
I'm going to get the plastic mity vac from harbor freight, bonus is that i can use it for the brakes on my truck too.
 
I'm going to get the plastic mity vac from harbor freight, bonus is that i can use it for the brakes on my truck too.
You'll wonder how you lived without it. I've just about worn mine out after several years.
 

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