Nik's Poulan Thread

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Bob,
Just a thought, but the 4000 I have, had the high top filter cover with the front facing air inlets. There were a couple of tiny Phillips screws up inside,
that held the internal plastic baffle to the top. When I pulled them to clean it all up, it was packed with mud & crap up in there. My point is that there very well may be a restriction you can't see
had the same thought but it was clean. Had a brain far# that possibly the impulse opening on the carb intake manifold may be partially blocked as I used some Dirko to seal the manifold. Will likely tear saw apart to check. Definitely something is wrong as I put the carb on my 3700 and it ran great.
 
had the same thought but it was clean. Had a brain far# that possibly the impulse opening on the carb intake manifold may be partially blocked as I used some Dirko to seal the manifold. Will likely tear saw apart to check. Definitely something is wrong as I put the carb on my 3700 and it ran great.

OK then, eliminated that variable on a possible blocked cover.
 
Here is the 361 all done accept for installing the NOS muffler
esyquqyq.jpg


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Tore apart my 4000 in order to check the intake manifold. There was a little sealant blocking the impulse hole but that wasn't the worst part. When removing the cylinder I found one of the bolts had broken off in the case. Not sure how that happened. Replaced it and saw runs much better. Not sure which fix worked.
 
Tore apart my 4000 in order to check the intake manifold. There was a little sealant blocking the impulse hole but that wasn't the worst part. When removing the cylinder I found one of the bolts had broken off in the case. Not sure how that happened. Replaced it and saw runs much better. Not sure which fix worked.

Does the WOT speed still change with the air filter cover screwed down?
 
Well, tried it and loosened air filter while running at wot. RPM's increase quite a bit. Wonder if its supposed to act like that? Seems I've seen guys put K&N filter stacks on saws to draw in more air for stronger running.
 
Well, tried it and loosened air filter while running at wot. RPM's increase quite a bit. Wonder if its supposed to act like that? Seems I've seen guys put K&N filter stacks on saws to draw in more air for stronger running.


Nope!

I'm gonna say there's still a leak there somewhere.


Mike
 
Nope!

I'm gonna say there's still a leak there somewhere.


Mike
Mike you may be right but I can't draw my head around it. If there was an air leak why would loosening the air filter cause it to run faster at wot? Other than that issue it idles and runs fine. Maybe I have to do a pressure and vacuum test again. I
 
Mike you may be right but I can't draw my head around it. If there was an air leak why would loosening the air filter cause it to run faster at wot? Other than that issue it idles and runs fine. Maybe I have to do a pressure and vacuum test again. I

Bob I believe the loosening of the air filter is allowing extra air in, making the mixture leaner and raising your rpm's.
When the filter is tightened down the leak is pushed together and sealed, richening the mix back up and lowering the rpms.
If you have a propane torch, you might be able to remove the top cover, start the saw and blow the gas WITHOUT LIGHTING IT, around the carb and intake.
If the rpm's drop when you blow the gas in a specific area......there's where you are leaking.


Mike
 
You mean it was lost in the shop , and you knew it was somewhere? That sounds more like something I'd do.
it is getting to that point with the stuff i have but know i have a few big old bars that are set up to run 404 X 050. I very kind member here made me up a couple chains last year or so but I wanted a roll for the shelf so i can make my own. I wonder how old that box is. 1960's i would guess.
 
Bob I believe the loosening of the air filter is allowing extra air in, making the mixture leaner and raising your rpm's.
When the filter is tightened down the leak is pushed together and sealed, richening the mix back up and lowering the rpms.
If you have a propane torch, you might be able to remove the top cover, start the saw and blow the gas WITHOUT LIGHTING IT, around the carb and intake.
If the rpm's drop when you blow the gas in a specific area......there's where you are leaking.


Mike
I agree that's what's going on. I did another pressurere and vacuum test and couldn't find any leaks. I assume the propane test would accomplish the same thing? I'll try it and see what happens.

Bob
 
I have been looking for this chain for over a year. 404x050
y8u8yve8.jpg


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You should have said something. I've known where .404 050 is since 07. He had tons of it last time we conversed long ago.
Now figuring out the guy I used to talk too and trade with that had it is another thing. Ole memory not so sharp anymore on some things.
 
have a member close to it pick it up for you
I would love to add this to my collection but the seller does not have PayPal and will not ship...

Portland245A4_zps59502e79.jpg
Wow, looks a lot like the one I sold on here a few months ago ;)
Picked up a much rougher one last night, but it's complete... mostly..
will get a pic up shortly
 
I agree that's what's going on. I did another pressurere and vacuum test and couldn't find any leaks. I assume the propane test would accomplish the same thing? I'll try it and see what happens.

Bob


Pressure and vac won't help you with what I think is wrong.
You seal past the leak I believe you have.
I also hope you understood that when I said remove the top cover, I meant the whole top cover not just the air filter cover.
When I read it back after I posted that, it seemed a bit vague even to me.


Mike
 
Bob,
It may have been mentioned but is the throttle shaft on the carb worn?
Also,
When I first fire up a saw after fuel lines and a kit I prime the carb with an eye dropper. I usually have to re-tune when it's buttoned down with the air filter in place as it generally runs richer. I don't have a tach to test it out. Did you ever consider trying the same test with one of your other 4000's?
 
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