Uh Oh!!!!!

[l2edneck]

I was gonna mod the muffler on my 390 till i seen this
View attachment 37478
View attachment 37479

So im thinkin shes ready to blow?
Im guessin thats what a scored piston looks like?
What is reccomended here?Its my main big saw and i aint got cash to put it in the shop rite now.Should i continue to run it?Or park it and make due with the Echo?Any help is very appreciated due to the fact that ima a complete moron but im learnin.

 

[1953greg]

piston looks like toast to me. piston n rings can be replaced for bout 40 bucks w/ aftermarket parts. cylinder is probably ok but wil need cleaning. needs to at least be smooth to the touch. the engine wil have to be removed from the chassis. difficult but possible w/ repair manual. saw wil be completely diasaaembled and the rear bar mount stud must be removed. took me bout 5 hours on my first one. would guess it could be done in 2-3 by a pro. manual is a must by anyone else. gut the muffler while u r at it and add another muffler exhaust port. then it wil really surprise you. and run cooler too. good luck.

 

[NWCS]

piston is scored big time, rings are broken. she is pretty bad off. if the cylinder is scored past the plating its probly best to sell it for parts. another saw would cost less. if the cylinder can be honed and salvaged you can get aftermarket pistons with rings from baileys for $35. i would say have the cylinder honed and if its usable, you have a good project to rebuild your own saw and save money.

 

[l2edneck]

Will this bolt up?

If im gonna spend the money i might as well go this route if i can?

http://store.baileys-online.com/cgi-bin/baileys/5538?mv_session_id=pAIiEUB5&product_sku=CK 038


Kinda like puttin bigger heads on a car?
Let me know if im just way off here.
If not do they sell a piston cyclinder kit for the 390?

 

[1953greg]

the 390 piston cannot be removed from the top of the engine. engine has to removed from the chassis and the bottom of the engine removed. the seperating point is the crank. the 038 is a completely different engine. its a toploader. 390 is a bottom loader. totally different design. havent seen an after market piston cylinder kit for the
390/039. aftermarket pistons r available if your cylinder is ok. the 038 is a "pro" model. those pistons can be replaced in 30-45 min. the 390/039 takes hours. dont attempt the 390 when in a hurry!!!
imo, if one has to pay shop rates the 390 probably isnt worth fixing. probably cost 200-400 for original parts n repair. maybe more. if u can do the work yourself might get out for 50 bucks if the cylinder is ok.

 

[retoocs555]

I was gonna mod the muffler on my 390 till i seen this
View attachment 37478
View attachment 37479

So im thinkin shes ready to blow?
Im guessin thats what a scored piston looks like?
What is reccomended here?Its my main big saw and i aint got cash to put it in the shop rite now.Should i continue to run it?Or park it and make due with the Echo?Any help is very appreciated due to the fact that ima a complete moron but im learnin.

Does it run like that?????

That piston is toast!

But if it runs and cuts, as the phrase goes, RUN IT LIKE YOU STOLE IT!

and when it dies, just sell it for parts and get something else, you won't hurt it any more by running it.

 

[l2edneck]

Short vid of 390

Does it run like that?????

I made this cut mins b4 discovering the issue!!!

View attachment 37484

 

[sawinredneck]

AWSOME PICS l2!!!!!!!!!!! That is very hard to get a pic of!!!!! If you are pretty handy, and VERY paitent, it can be done, but it SUCKS!!!! And is very tedious! Shop rate will kill you, like they say, 200-400, you can get a new one around here for $490. Kinda pointless!! If you can't fix it, like was said before, run it till she blows, make some cash and get a new one, or maybe someone on here will come up with a nice used pro saw (which you need BTW, that was another reason I sold my 390, used it too much for what it was) and you can pick up a pro saw for a decent price!
Sorry dude, that sucks!!!
Andy

 

[l2edneck]

definitly gonna try only paid 200 for it and has been a good saw so if i can fix it myself for like 100 i will.Need a service manual if ne 1 got 1 they aint usin (or online in pdf)If not ill have to hit the dealer on mon and see if i can maybe squeak 1 from them.Im definitly eager to learn small engine repair is something im interested in learnin.And i can always use an excuse to buy more tools.

 

[computeruser]

AWSOME PICS l2!!!!!!!!!!! That is very hard to get a pic of!!!!! If you are pretty handy, and VERY paitent, it can be done, but it SUCKS!!!! And is very tedious! Shop rate will kill you, like they say, 200-400, you can get a new one around here for $490. Kinda pointless!! If you can't fix it, like was said before, run it till she blows, make some cash and get a new one, or maybe someone on here will come up with a nice used pro saw (which you need BTW, that was another reason I sold my 390, used it too much for what it was) and you can pick up a pro saw for a decent price!
Sorry dude, that sucks!!!
Andy

+1 on all points.

Keep your eyes out for a crushed saw, that might be your best bet. Even if it means turning it into a 290 or 310, you might be better off rebuilding it as that and selling off the resulting saw at inflated eBay prices.

You should be able to find a good used pro-grade saw (360, 440) for about $200-300. Our normally crappy pawn shop had a like-new 360Pro for $170 the other day. I brought it to the counter to buy it when some fellow came running up with the manager, who was saying that this customer had called about the saw and asked that it be set aside, but he got caught up in traffic and the manager forgot to set it aside. The poor guy was so frantic looking, I let him have it.

If you part out your 390 on eBay, you could probably recover most of the cost of the good replacement saw.

 

[THALL10326]

I was gonna mod the muffler on my 390 till i seen this
View attachment 37478
View attachment 37479

So im thinkin shes ready to blow?
Im guessin thats what a scored piston looks like?
What is reccomended here?Its my main big saw and i aint got cash to put it in the shop rite now.Should i continue to run it?Or park it and make due with the Echo?Any help is very appreciated due to the fact that ima a complete moron but im learnin.

Continue to run it you say, will it still start?? That piston looks cooked real good, surprises me it will start...

 

[Kneejerk Bombas]

Ebay!

 

[b1rdman]

I have "a friend" (he he) that is NOT very good with this stuff but very interested in learning.

Does anyone have a pic of what the piston should look like?

"Add another muffler exaust port"...Just open up the muff with a dremel?

Rings are broken? What are you seeing that tell you this.


Thanks from "my friend" (shhhhhhhh...it's really me)

 

[ShoerFast]

Not for dial up

Rings are broken? What are you seeing that tell you this.

Note the shadows.

 

[RED-85-Z51]

Im just curious...were you running an air filter?:jester:

 

[l2edneck]

Whats yer idea on why?
I got maybe 40 hours on the saw.
i bought it used and had already had a new carb.
Then i had a "fuel line issue"
Im thinking some one may have either:

#1 ran it out of gas and caused damage?

#2 was usin wrong mix ratio?

#3 maf. defect?

Just curious, and want to say ty to you all fer responding.

 

[l2edneck]

Does anyone have a pic of what the piston should look like?

This my original 335xpt which now i see has a broken ring but alot less scoring.Still not what 1 should look like.
View attachment 37505
edit:the side of the 335 opposite the broken ring is smooth as glass.

And ty shoe i was wonderin if maybe just oil on the piston becuzz feels smooth.

Definite Rebuild on the 390.
im eager to try it out.

 

[Lakeside53]

Whats yer idea on why?
I got maybe 40 hours on the saw.
i bought it used and had already had a new carb.
Then i had a "fuel line issue"
Im thinking some one may have either:

#1 ran it out of gas and caused damage?

#2 was usin wrong mix ratio?

#3 maf. defect?

Just curious, and want to say ty to you all fer responding.

If you had a bad (split) fuel line and sucked air, you ran it lean and toasted the piston/cyinder.

If you used the wrong gas mix, sure... but it would have to be really bad or no oil!

 

[sawinredneck]

l2, I am leaning to the lean out, as well as running that with the 28" bar, I firmly belive (even more so now) that is just too much for that saw!!! Like Lake said, it doesn't take long with a lean motor to set things in motion, and with that big bar bogging the saw down and heating it up more, toast, real quick like!!!
Andy

 

[Diesel JD]

That's why I dumped the 28" bar. I decided that it was making it work too hard. Seems to work well with the 25" though and the 16" bowguide. That being said, I am curious how that happened I don't want to hurt mine like that. I'm thing the l2 didn't do this that the PO did. I wonder if it was a cleanup saw from some of the hurricanes, which after the trees were cutup, some property owner didn't need anymore, why you got it cheap? This seems to have beena common model sold during our last couple of years here with too many hurricanes.