New to me 038 AVS Farm boss rebuild

[Jinx3Mt]

So bare with me here. I've read just about every 038 AV post on this forum and need a little direction. My 038 AVS Farm Boss won't start. I have replaced just about everything but Piston and Cylinder. I bought cheap crank seals that ended up being either the wrong ones or cheap ones that leak. My local dealer ran a pressure and vacuum test on it and told me the new seals leak and by the way the piston and cylinder need to be replaced. They also said it's not worth fixing because it's old. The other dealer wouldn't even touch it. I took that as a challenge.

The other thing is after putting it back together from replacing the crank seals it started and idled after the first pull for 20-30 seconds and then wouldn't start again. Question is where can I get good aftermarket seals, and the piston/cylinder kit so I can get it running.

Last thing. There are enough people that love the 038's that I think they should have a dedicated thread or group.

 

[pioneerguy600]

I like to keep the 038`s running, own a magnum but have built many others. Have only used OEM parts as the AM stuff is really hit or miss order after order, sometimes usable but often enough they just aren`t worth messing with them.

 

[Jinx3Mt]

I like to keep the 038`s running, own a magnum but have built many others. Have only used OEM parts as the AM stuff is really hit or miss order after order, sometimes usable but often enough they just aren`t worth messing with them.

The problem is the dealer said they can't get the seals and they don't have a listing for the P&C

 

[pioneerguy600]

The problem is the dealer said they can't get the seals and they don't have a listing for the P&C

The dealers aren`t much help now, one must become a sleuth of sorts. I have found parts for saws made from 1945 onward during my restorations. Parts are out there but it takes effort to find them.

 

[Jinx3Mt]

thx. I'll keep looking. Does anyone else have a good aftermarket source for crank seals, and piston/cylinder kits?

 

[Mad Professor]

Stihl dealer # 1119 007 1050 ,set of gaskets w/seals ~$18

Don't buy Chi-Com junk

 

[Mad Professor]

038S stuff is getting hard to find. Piston is NLA and P/C kit is ~$300 from Stihl.

I'd look for a good used 038M cylinder, get a Meteor piston and convert it to a 038M

Tecomec used to make quality 038M kits in Italy, they still list the kits but they are Chi-Com now

 

[Jinx3Mt]

Any opinions on Pro line products?

 

[jp233]

I got something from them a month or 2 ago..... can't precisely put my finger on what though, I've got CRS. I think it was carb rebuild kit for a Mac 610, was OEM or sure looked like it

 

[Vintage Engine Repairs]

Your local bearing supplier or tractor supplier will sell crank seals if your dealer can’t source OEM. The info for the seals is in the IPL, pop over to the beg for manuals sticky

Can your cylinder not be cleaned up?

 

[Mad Professor]

Your local bearing supplier or tractor supplier will sell crank seals if your dealer can’t source OEM. The info for the seals is in the IPL, pop over to the beg for manuals sticky

Can your cylinder not be cleaned up?

Tom , I posted the gasket/seal kit info above. Kit is cheaper than seals. I can't see buying Chi-Com seals if OEM is available and price is reasonable

It's getting tough to source quality 038S 50mm pistons. That's why I suggested a 038M conversion

 

[Jinx3Mt]

Tom , I posted the gasket/seal kit info above. Kit is cheaper than seals. I can't see buying Chi-Com seals if OEM is available and price is reasonable

It's getting tough to source quality 038S 50mm pistons. That's why I suggested a 038M conversion

Thank you both. Hopefully I can tear it down this weekend and see how bad everything is.

 

[Mad Professor]

Thank you both. Hopefully I can tear it down this weekend and see how bad everything is.

Pull your clutch and flywheel before you remove the cylinder.

 

[Jinx3Mt]

Your local bearing supplier or tractor supplier will sell crank seals if your dealer can’t source OEM. The info for the seals is in the IPL, pop over to the beg for manuals sticky

Can your cylinder not be cleaned up?

I got the manuals. Thx

 

[Jinx3Mt]

so i had a chance to pull the muffler of and look at the piston and cylinder. They look amazing to me. Correct me if I'm wrong please. When I get some time I'll look seals. I wonder if the seals were just crap. P&C pics attached u should be able to zoom in. Any opinions.

 

[Mad Professor]

Some carbon buildup below lower ring. Rings probably getting worn. What is compression?

My guess is that piston should clean up from the carbon , and then check P/C clearance. If not too worn a set of rings might be all you need for P/C. $tihl rings are expensive, get Cabers. Post what you have for compression and/or pictures of piston/cylinder if you pull them off. Clean up real good before if you do.

I'm assuming saw has good spark?

 

[Jinx3Mt]

Just rechecked compression and its between 105-110 and holding. I'm Thinking i need 140ish so a rering is in order. I ordered the rings and gasket set so hopefully that's it.

 

[Vintage Engine Repairs]

When you say “it’s holding” note that the pressure during a compression test is held via the shrader valve, not the cylinder


You are mixing up a pressure / vacuum test and a compression test in one. You could unscrew the compression tester from the spark plug threads and it will still hold hehe.

 

[Jinx3Mt]

True