Nik's Poulan Thread

[fossil]

This baby is running hawt!!

View attachment 676857
Biggest mud dauber nest that I had ever seen in a saw...

You need to get their little wings flapping.

 

[hotshot]

You need to get their little wings flapping.

Lol, little wings.

I’m just glad that they didn’t get into the muffler, another reason to leave the screen in.

Lucky the top end is fine, even though it had to have ran hot. Another example of how tough these older saws are. That nest pulled the kill wire’s flag terminal off, so that gets resoldered.

Had a huge wrong size J8 Champion in it. I don’t know how in the hell they ever got a socket on it. I used channel locks on the porcelain to get it out...

It also needs the standard S25CVA marching order items consisting of new upper isolator mount, fuel line, air & fuel filter, crank seals, cap duckbill, spark plug, oiler diaphragm, carb kit, and a good degreaser & hot water douche.

Will be running in the morning...plan on taking P&V test hookup pics for the oiler, exhaust & intake blinds for a fellow on the main forum that wants to know how to check the seals & jug base gasket for leaks on his S25.

 

[hotshot]

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.



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.



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...




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.



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



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.

 

[Todd Loosli]

Thanks for the great lesson learned a lot

 

[RAS61]

I just picked up a 3800 in Craftsman gray and black. As I understand it the main difference from the 3700 is a chrome piston instead of a chrome lined cylinder. Was this a cost saving measure? Is there any other significant differences including performance?

 

[hotshot]

Yes, a cost savings move. They’re still a great classic firewood saw.

Compression in the 3800 was lower, versus a 3700, so the 3700 seemed to always be faster in the cut. It’s not a “significant” amount though, for bucking logs.

The thin piston rings in the 3700, plus the chrome bore may have helped increase the compression.

Ignitions, carbs, and crankshafts were the same.

If you add a side port to the muffler & delete the base gasket (after checking squish band clearance), you could be on par with the stock 3700.

 

[fossil]

The 3800 will have lower compression that the 3700. Usually around 130 -140 psi. Both good saws. The 3700 has a slight edge in performance but not really noticeable. unless you run them side by side as I see it.

Easy to tell what you have by the rings looking through the exhaust port. 3700 on the left 3800 on the right

 

[hotshot]

Great minds think alike....

 

[fossil]

Great minds think alike....

Some days I think mine's on the way out.

 

[svk]

Well this one is going to be a donor saw. Scoring on piston is pretty deep, ring is stuck and seals were partially melted. Also the sealant used on the bearing cap appeared to had deteriorated and perhaps there were air leaks in there.

Saw has a broken brake band too.

 

[Todd Loosli]

ATTACH=full]676941[/ATTACH] the red cylinder is a 3700 and the other is a 3800 looking at the muffler side. If you square out the top corners of the 3800 you almost have a 3700 in performance

 

[RAS61]

If you add a side port to the muffler & delete the base gasket (after checking squish band clearance), you could be on par with the stock 3700.

I was thinking of doing a muffler mod, provided it's worth it, anyone have experience with this? If so I'd like to find some good how to instructions to do it right. So far I haven't been able to find anything, just a bunch of videos of guys cutting wood after the fact.

 

[Todd Loosli]

I made a thing that will turn a 3400 muffler into a 4000 muffler . I'll get a picture posted

 

[Todd Loosli]

Made this to make a 3400 into a 4000

 

[RAS61]

Made this to make a 3400 into a 4000View attachment 676942

I understand the port slit on top, but what are the 2 silver bars?

 

[Todd Loosli]

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

 

[s sidewall]

Well this one is going to be a donor saw. Scoring on piston is pretty deep, ring is stuck and seals were partially melted. Also the sealant used on the bearing cap appeared to had deteriorated and perhaps there were air leaks in there.

Saw has a broken brake band too.

View attachment 676934 View attachment 676935

Looks like it got pretty toasty.

Steve

 

[s sidewall]

I had to demod my 3400 muffler front half, someone drilled 9 holes in the front. Was too loud and would char the wood, welded the holes backup and enlarged three of the baffle holes. Thought about doing a louver like that, that one looks nice. I had another 3400 muffler but it has holes drilled into the front also.

Steve

 

[hotshot]

I was thinking of doing a muffler mod, provided it's worth it, anyone have experience with this? If so I'd like to find some good how to instructions to do it right. So far I haven't been able to find anything, just a bunch of videos of guys cutting wood after the fact.

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.

Run the pizz out of it, cutting up your wood stove fodder.

 

[svk]

Looks like it got pretty toasty.

Steve

Yeah, we processed several large cottonwoods with it. They day it died we had done 3 tanks of fuel nonstop. This summer I think I processed 7 trees over 20" with it for my aunt and they had the saw for something like 11 years so definitely got their money out of it. The brake band had been broken prior to my first using it.