Jonsered 2077T piston alternatives

[Jason_WI]

So my dad borrows out my Jonsered 2077T with the 28" bar on it. It comes back with no compression and a melted piston. >:( >:( >:(

Parts are unobtanium for this saw. I just put a new Husky clutch, bar and chain on not that long ago. I haven't taken it apart yet to see if the cylinder can be salvaged. Reading around on the net I found that a Stihl MS460 piston is a drop in replacement. Have any of you here heard of this?

How do I check the crank seals to see if there is an air leak? The saw will not run. I have used ether in the past to find leaky crank seals but that was on a running snowmobile engine. Pressurize and use soap to find bubbles?

I know this is the same saw as a Poulan Pro 475 and a Partner 7700. I hate to gamble on ebay parts saws as you knever know what you are getting. Some joker wants $140 for a Poulan Pro 475 parts saw on ebay now. Claims to have a good engine....... has neg feed back for a poulan pro 475 that was supposed to run but didn't....

Thanks for any help.

Jason

[Cut4fun]

I just stuck a 52mm afm big bore 372 piston in my 475 aka 2077. Runs great.  Drop in no modding piston at all.

You can also put a 064 piston in but you will need to open the wrist pin bosses to clear rod. Stihls pistons need bosses opened up, not a drop in for 064 046.

[Cut4fun]

These are known for bad seals and crank bearings. I own 5 or 6 of them, lost count.  :D

[Jason_WI]

Here is the forum topic where I found that the 460 piston will drop right in:

http://www.arboristsite.com/chainsaw/117805.htm

Where does one find seal kits and gaskets for these saws? I would like to get mine back up and running.

Will this piston work:

http://www.baileysonline.com/itemdetail.asp?item=PKM+372BB&catID=

Thanks

Jason

[Cut4fun]

Where does one find seal kits and gaskets for these saws? I would like to get mine back up and running.

Will this piston work:

http://www.baileysonline.com/itemdetail.asp?item=PKM+372BB&catID=

Thanks

Jason

I dont know if I can say where online here because they have sponsors.  Just look at my 505 475 415 threads on chainsaw repair site.  http://chainsawrepair.createaforum.com/index.php

Yes that is the 52mm piston I used. 

I would use a 064 piston before the 046 piston if I was using stihl pistons anyways. All because of the measurements.  ;)

[Rob-IL]

About 25+ years ago I put a O56 piston in a 920 Jonsered, I remember I had to shim up the cylinder with 3 or 4 gaskets so the hemi piston ( the origional Jonsered piston was flat top) wouldn't hit the top of the cylinder. Other than the cylinder bolts tried to loosen up once before lock tighting them, it ran & cut like a raped ape for quite sometime.

[nhlogga]

Have you tried chainsawr.com? They are a site sponsor and are fantastic to do business with.

[Al_Smith]

FWIW a Stihl 038 magnum is also 52 MM .

On those seals if you have the OEM part numbers often times they can be cross referenced with something like CR or some other manufactures .Stihl being Stihl is just about the only manufacturer with odd all size seals you can only get from a dealer .