Burned up MS390

[NEK VT]

So someone mistakenly put streight gas in the saw, and killed the piston and cylinder. The Stealer said it would cost the same as buying a new saw to fix. He ended up buying a saw. Anyway I found a cylinder and piston kit for 50 bucks on ebay and I ordered it so I can rebuild it. I was looking and i noticed the cylinder bolts look like they screw in from the bottom up into the cylinder... Do I hafta pull the bottom plastic off the saw to get to them? no big deal if I do... I just will have to wait until I have a little time to tear it all the way down. Also, anyone had good luck with these aftermarket top end kits?

I still also have my 390 its been a damn good saw to me.. I bought them both new a few years ago now. I have been so busy lately I havent been cutting my firewood like I should and I have about 11 cord of wood waiting to be cut. Hopefully after these crasy next couple weeks are over Ill have some time to cut wood after work every night.

 

[Hedgerow]

So someone mistakenly put streight gas in the saw, and killed the piston and cylinder. The Stealer said it would cost the same as buying a new saw to fix. He ended up buying a saw. Anyway I found a cylinder and piston kit for 50 bucks on ebay and I ordered it so I can rebuild it. I was looking and i noticed the cylinder bolts look like they screw in from the bottom up into the cylinder... Do I hafta pull the bottom plastic off the saw to get to them? no big deal if I do... I just will have to wait until I have a little time to tear it all the way down. Also, anyone had good luck with these aftermarket top end kits?

I still also have my 390 its been a damn good saw to me.. I bought them both new a few years ago now. I have been so busy lately I havent been cutting my firewood like I should and I have about 11 cord of wood waiting to be cut. Hopefully after these crasy next couple weeks are over Ill have some time to cut wood after work every night.

You will want to remove the whole motor assy. from the plastic case it's cradled in. Give her a good cleaning while you got it all apart. As far as AM jugs and their quality, I have no experience with them.

 

[NEK VT]

Thanks

Thanks, Ill look and see how it comes out of the cradle... I have rebuilt lots of saws, just never a newer stihl with all this plastic.
I am thinking after I rebuild it it will probally be trouble free for years as I tend to take pretty good care of stuff. It will be nice to have a backup saw. keep em both sharp and I wont hafta stop and sharpen my chain while i am working all day. BTW speaking of that, has anyone else noticed that stihl chains dont hold a sharpening even a quarter as long as Oregon chains? I compleatly gave up on stihl chains a few years back because of this... I really like the oregon ones so much better, and they are cheaper.

 

[NEK VT]

also i wanted to add

I also wanted to add, that when i went and picked up the saw yesterday, I was given a bag of perts (stealer dident even put back togather) , but luckely ever nut was accounted for and i put it all back togather loosely just so stuff dont get lost. Also... I actually found it kind of funny that the foolish Stealer guy dident even dump out the streight (obviously clear) gas. I dont know but it just seems weird to leav it in there just waiting for someone to do a rebuild and not remember to change the gas and do it all over again....oh well Ill use it for cleaning parts.

 

[blsnelling]

The entire saw has to come apart to replace the piston and/or cylinder. Not a fun saw to work on.

 

[SawTroll]

Those saws aren't meant to be worked much on - they are disposable cunsumer class saws. :msp_sneaky:

 

[sefh3]

In my signature there are a few threads that will help you reassemble this saw.

 

[Hedgerow]

Those saws aren't meant to be worked much on - they are disposable cunsumer class saws. :msp_sneaky:

Maybe... But they're SEXY!!!

You know you want one!!!
:hell_boy:

 

[NEK VT]

wow thank u so much

That rebuild link is gonna save me so much time.....BTW looks like only one bar mounting stud is removed? Left handed threads on that stud just like any other I am asuming?
That cooked piston at the end is about what this one looks like.
Now I actually cant wait to get started.

 

[blackoak]

Those saws aren't meant to be worked much on - they are disposable cunsumer class saws. :msp_sneaky:

Call them what you like troll, but the 290-310-390 are still the number one selling saws in the world and are Stihl's bread and butter. We get the drift that you are not fond of this series, but many consumers are. The after market 390 P/C kits are going to make someone very rich

 

[sefh3]

Check your fuel lines. I know you said it was straight gassed but the lines are known to crack and will cause it to seize.

 

[NEK VT]

yeah i will look at them

yeah ill look at the lines, I have seen a lotta sleds get cooked that way, cracked lines and carb boots..

 

[angelo c]

yeah ill look at the lines, I have seen a lotta sleds get cooked that way, cracked lines and carb boots..

you are already there...might as well change out the lines. real easy once the saw is apart.
don't listen to the guys saying its not a worthy saw. I actually think the rebuild on the "clamshell" is easy once you have done a few. I would look close at the bearings and seals as well. Seals for sure, bearings as needed. check out the yamabond for the case seal.

 

[H 2 H]

I did a MS 310 couple months back that was straight gas its easy to rebuild them

 

[NEK VT]

you are already there...might as well change out the lines. real easy once the saw is apart.
don't listen to the guys saying its not a worthy saw. I actually think the rebuild on the "clamshell" is easy once you have done a few. I would look close at the bearings and seals as well. Seals for sure, bearings as needed. check out the yamabond for the case seal.

I have to agree my other saw is identicle and its has been a great saw with no issues. I have done a lot of lot clearing, road building and firewood with it. I also have used yamabond in the past on snowmachine cases. It does work good... As for seals I was thinking I probally would change them as well and have a look at the bearings, there is a chance that little pieces of piston ring might have gotten in them when all this happened.

ps....awsome signature!!

 

[nstueve]

if you haven't done so yet... pull your limiter caps and do a muffler mod. Definatly helps to give these saws more power and reliability. Keeping the filter cleaned is the biggest problem with these saws. If they were a lighter and had better air filtration no body would complain about them. They are still a good wood cutting saw.

If your running it yourself... replace the impulse b/c it's a PITA to break the saw down later times savings alone would be worth the cost of the impulse line. The fuel line can be replaced with the saw together if need be... Go to Chainsaw Parts and get an impulse line and new oil seals. They are cheap insurance that will keep you from breaking down the saw again any time soon!!!!

Also... Check the cylinder when you get it... I usually have to clean up the AM cylinders intake and exhaust with some sand paper or a dremel.

 

[NEK VT]

yeah

if you haven't done so yet... pull your limiter caps and do a muffler mod. Definatly helps to give these saws more power and reliability. Keeping the filter cleaned is the biggest problem with these saws. If they were a lighter and had better air filtration no body would complain about them. They are still a good wood cutting saw.

If your running it yourself... replace the impulse b/c it's a PITA to break the saw down later times savings alone would be worth the cost of the impulse line. The fuel line can be replaced with the saw together if need be... Go to Chainsaw Parts and get an impulse line and new oil seals. They are cheap insurance that will keep you from breaking down the saw again any time soon!!!!

Also... Check the cylinder when you get it... I usually have to clean up the AM cylinders intake and exhaust with some sand paper or a dremel.

Yeah I figured I would probally need to clean it up a little once it arrives.
Hopefully I can get my backhoe back togather this week and cut some wood, and tinker on this later in the evenings.

 

[Fish]

I also wanted to add, that when i went and picked up the saw yesterday, I was given a bag of perts (stealer dident even put back togather) , but luckely ever nut was accounted for and i put it all back togather loosely just so stuff dont get lost. Also... I actually found it kind of funny that the foolish Stealer guy dident even dump out the streight (obviously clear) gas. I dont know but it just seems weird to leav it in there just waiting for someone to do a rebuild and not remember to change the gas and do it all over again....oh well Ill use it for cleaning parts.

How much did he charge for the estimate, and what was the estimate?

 

[NEK VT]

Estimate

How much did he charge for the estimate, and what was the estimate?

He simply told my father that it would cost more to fix then to buy a new saw.. and my father took his word for it and bought a new saw. I wish I would have known this happened before he went to the dealer.

 

[Fish]

So he didn't charge him anything, and you are calling him a "stealer"?????????????