2139 aka 338xpt light rebuild

[davidwyby]

Got this 2139 used recently from a guy on one the saw groups on fb. Think it’s an ‘08, used by a tree co. Checked it out when I got it, pulled muffler, 150psi compression. I like it, but apparently it’s like all my other saws and is mad at me at the moment. Running wonky when tilted, so vac/pressure test, crank seals leak. More vacuum leaks than pressure. Boot seems to be a problem area, was hoping that was all it was, but it only almost had a hole. So, pulled the case apart and had to take piston off to get sheet metal bearing holder gasket thingy off. Discovered the rod has been rubbing one side of the piston. Inside of rod and bearing shows a little heat signature on that side. What do y’all think? Something crooked/misaligned it would seem to me.

 

[Adirondackstihl]

Probably lived its life @ 50:1 and the consumable parts have gone past their service life.
Just my opinion though, judging by the bearing needles and the bottom side of the piston.
More than likely the seller knew something was wrong with it, hence why he sold it.

 

[Dub11]

@beaglebriar didn't you rebuild one of these awhile back?

 

[beaglebriar]

I had one for a while. Did a few repairs to it but not a full rebuild. Decent power just wasn't 100% in love with it.

Replaced it with the t540. So far I really like that little saw.

I believe that intake boot was problematic on some of the 335/338's.

 

[beaglebriar]

I'd say the crank wasn't centered in the case??

 

[Adirondackstihl]

I'd say the crank wasn't centered in the case??

Easy fix if that’s the case.
I’d be lookin at the crank bearings closely

 

[beaglebriar]

Easy fix if that’s the case.
I’d be lookin at the crank bearings closely

Definitely.

 

[davidwyby]

Bearings seals/holders are getting replaced. Gonna pay careful attention to alignment when I reassemble. Thanks

 

[davidwyby]

Reckon I'll try this trick by @ABarrick along with timing and muffler

" On my 2135, I also removed the steel plate on the back of the flywheel and just used nuts to hold the starter pawls on. Sheds quite a bit of weight which helps spool up."

 

[davidwyby]

@David Young here it is

 

[davidwyby]

Does anyone know of a good rebuild thread for these? It’s been too long

 

[davidwyby]

Almost got it all together. Covers, etc. left. Hopefully it will rain firewood tomorrow, got the towable bucket lift in the driveway.

pressing the brg on


Added some motoseal to this gasket for good measure

thanks @Benwa

 

[davidwyby]

Three steps forward, two steps back. Should have known better. Got it 99% together to test run and the fuel pumped out the bottom of the saw.

 

[davidwyby]

Replaced the line...went to run, carb flooded. Disassemble, clean out, reassemble, runs, but no oil. I’m out of practice and this thing did not appreciate me leaving it in pieces. One more time...

 

[davidwyby]

Finally.

These things are a pain. Tear completely down to get at the pump.

 

[davidwyby]

 

[davidwyby]

Rabbit trail...

https://opeforum.com/threads/jred-2139-aka-338xpt-flooding-zama-c1q-el33a.22786/#post-1163827

 

[davidwyby]

2139 flywheel on the right, 335 on the left. Either will run but I don’t know how critical the 335’s straight fins are vs. the curved 2139.
Below is the back of the 2139 flywheel with weight removed, tip from @ABarrick


Knife tip is pointing to area where I removed ridge that cuts the boot.



piece of trimmer string heated, bent, flattened on the end for a redneck thread repair in plastic...but it worked so well I might just leave it.

 

[davidwyby]

I finally took the time to get this little booger properly tuned tonight and made $50 worth of pink cookies to sell to teh ladies.


Also the knucklehead that put the handle in the way of the filler holes is the reason I keep bar oil in squeeze/squirt top bottles.

 

[davidwyby]

This little Booger...don’t use it much but when ya need it, ya need it. Ever since the crank seals went, it’s broke more than it runs. Thinking about getting a little echo for a backup and lighter top handle...

Took it up to the mountains...running fat as expected due to elevation...go to lean it and go all the way lean and still 4 stroking. Went ahead and did some cutting, low power, fiddled with carb adjustments and finally stalled in the cut a couple times and wouldn’t idle so I put it away. Nother tree job next weekend, need this and the lift fixed...