Nik's Poulan Thread

[challenger]

Outstanding instructions. Thanks

Challenger,

This is how I test those S25 series, but there are many ways to skin a cat...also normally don’t work on a saw this nasty, but knew you needed a “how to” set of photos quickly.

Pull the carb & put a rubber wedge under it, & snug it back down. This wedge is made of 1/8” thick Viton, cut in a pie shape in honor of Mastermind’s fondness of pecan pies.

View attachment 676897 View attachment 676898

Then pull the muffler, I have made sheet metal blanks with Viton backer gaskets for a dozen different family of saws, but again you can use a rubber piece cut to seal it. You’ll then snug the muff down over the rubber, like you did the carb.

Screw in the spark plug pressure test adapter, this is an easy to find Husqvarna made tool.

View attachment 676911 View attachment 676912

Now it gets interesting, pull the oil pump cover and stick a small plug in the impulse hole shown. This is a clear plug of silicone tube, then bend it over the oiler diaphragm & put the cover back on, over it all. This seals the impulse off. Note the two screws had not been put in the cover yet. The center screw goes completely through the crankcase, and tightens the pump again it, so that’s why you have to put the cover back on...

View attachment 676916 View attachment 676915


Pump it up to 8# with a cheap homemade blood pressure tester attached to the spark plug fitting. I never even made it to 4#, the PTO seal leaked like a sieve.

View attachment 676917

Watch the PTO seal make soap bubbles, the seals are very old in these saws...and never pass.

View attachment 676920

After fixing a gasket or replacing the seal in this case, retest by pumping back up to 8# & look again for leaks. Brush soap bubbles on the case jug gasket. This one passed after the PTO seal was replaced, but I replaced the FW side seal too. The saw should hold 8# all day long.

Now hook your vacuum tester up to the spark plug adapter & pull 15”Hg, this one passed fine. Of course it did, both seals were new!

Hope this helped, but there are already a bunch of test threads if you do searches & read.

Sent from my Pixel 2 using Tapatalk

 

[svk]

They are the top and bottom of the lover former. I'll get a picture tomorrow. You can send me a muffler body and I'll stamp it ,you pay postage only. That offer is open to anyone who wants one

That is a neat system and very generous offer.

 

[Todd Loosli]

Another view

 

[svk]

What kind of press do you put them in?

 

[Todd Loosli]

I use the 2 3/8 bolt holes and just tighten till it is correct looking

 

[svk]

Cool

 

[RAS61]

Way back on page 1720. It’s a bit loud, but sounds like a Traxx dune buggy on wide open throttle, and yes it’s worth it.

On those 3800s, I like to Dremel cut a side hole out of the main body & braze in a 3/4” copper street ell. I don’t own a tig welder, else it would be steel.

You also have to radius a sliver out of the back plate for ell clearance.

Then I cut the 3x3 hole array out of the top & bottom of the diffuser with the same Dremel & carbide cut off discs. I leave the back exit holes alone & put a new screen back in, but that’s up to you.

Seems to prevent the ever melted top cover edge, but also put a foil tape piece across the top cover inside lip...

Paint it with high temp paint.

View attachment 676982

That looks sweet, thanks! Do you or anyone else do anything with the diffuser or screen inside?

 

[RedneckChainsawRepair]

Wonder what could be in this big heavy box .
Ready to ship for next owner.

 

[hotshot]

What kind of press do you put them in?

600 ton Bliss, lol

 

[Todd Loosli]

I open up the diffuser 3/8 center, l,r,up, dn in a cross. I leave the screen alone cuz I cut in national forest. The port on the 3800 and 3400 makes a real difference when opened up in the corners.

 

[hotshot]

That looks sweet, thanks! Do you or anyone else do anything with the diffuser or screen inside?

Seriously? You need to slow down & read my thread again...

 

[Todd Loosli]

600 ton Bliss, lol

You are correct but it takes 2 passes

 

[RAS61]

Seriously? You need to slow down & read my thread again...

View attachment 677054

Yes, sorry, I was bouncing around with multiple new posts and not reading closely

 

[stubnail67]

Challenger,

This is how I test those S25 series, but there are many ways to skin a cat...also normally don’t work on a saw this nasty, but knew you needed a “how to” set of photos quickly.

Pull the carb & put a rubber wedge under it, & snug it back down. This wedge is made of 1/8” thick Viton, cut in a pie shape in honor of Mastermind’s fondness of pecan pies.

View attachment 676897 View attachment 676898

Then pull the muffler, I have made sheet metal blanks with Viton backer gaskets for a dozen different family of saws, but again you can use a rubber piece cut to seal it. You’ll then snug the muff down over the rubber, like you did the carb.

Screw in the spark plug pressure test adapter, this is an easy to find Husqvarna made tool.

View attachment 676911 View attachment 676912

Now it gets interesting, pull the oil pump cover and stick a small plug in the impulse hole shown. This is a clear plug of silicone tube, then bend it over the oiler diaphragm & put the cover back on, over it all. This seals the impulse off. Note the two screws had not been put in the cover yet. The center screw goes completely through the crankcase, and tightens the pump again it, so that’s why you have to put the cover back on...

View attachment 676916 View attachment 676915


Pump it up to 8# with a cheap homemade blood pressure tester attached to the spark plug fitting. I never even made it to 4#, the PTO seal leaked like a sieve.

View attachment 676917

Watch the PTO seal make soap bubbles, the seals are very old in these saws...and never pass.

View attachment 676920

After fixing a gasket or replacing the seal in this case, retest by pumping back up to 8# & look again for leaks. Brush soap bubbles on the case jug gasket. This one passed after the PTO seal was replaced, but I replaced the FW side seal too. The saw should hold 8# all day long.

Now hook your vacuum tester up to the spark plug adapter & pull 15”Hg, this one passed fine. Of course it did, both seals were new!

Hope this helped, but there are already a bunch of test threads if you do searches & read.

very cool post!!!

 

[hotshot]

Yes, sorry, I was bouncing around with multiple new posts and not reading closely

I’m just kidding you!

Others drill the the 18 holes out to a larger size, but that diffuser is still too restrictive when you calculate the open or “free area” for the exhaust gasses to pass.

 

[scottr]

I open up the diffuser 3/8 center, l,r,up, dn in a cross. I leave the screen alone cuz I cut in national forest. The port on the 3800 and 3400 makes a real difference when opened up in the corners.

Todd , I don't understand what port you are talking about .
Are you talking about the baffle plate with the six holes ?

 

[Todd Loosli]

This is what I do 3/8 holes

 

[Todd Loosli]

exhaust port on 3400,3800 open the top corners like the bottom is

 

[scottr]

Thanks .

 

[Todd Loosli]

If you see me say hello , I always wanted to meet those of you who are on here