290/390 woes

[FourMoCajuns]

A friend of mine got a 290 for fathers day 2 years ago. About 15 months after that it was adjusted by a family member resulting in a lean condition and it smoked the motor.(At least that was the general concesus) He took it to a Stihl dealer and had it repaired with a new 390 jug/piston. Well he was cutting tonight and when he was limbing he leaned the saw to the right and gave it full throttle but it only came up to about 1/4 rpm. He continued to cut until it was almost out of fuel and he shut it off. He then noticed that there was blue smoke coming from the left side of the body of the saw. He let it cool and took off the muffler and he described a 1/8th inch wide shiny line down the piston. He started the saw but said it ran like crap. What could cause the fuel delivery problems and could these two conditions be related?
He is definately not adjusting the carb ( they scare him) so it was still set from the fresh rebuild which was only 2 gallons of gas ago!

Any ideas?

Chris

 

[Lakeside53]

Yes it could be related. If you have a split fuel hose, you can suck air and get a lean condition. Could also be a blown seal sucking air real bad. Take it back it the dealer.

 

[Uwharrie]

FourMoCajuns, On the original engine, I feel for your friend. If his saw was repaired by a Dealer I would bring it to them and let them look at it. As for a common problem we see with Stihl saws is the Fuel Lines, holes in the line between the tank and carb. I recomend using oils that are JASO FC grade or above however it is not required as Stihl Oil has not been rated this high until the new oil reaches the shelves that they have out. There are so many variables to what happened and you would have to see the damaged engine to determine.

 

[computeruser]

Any ideas?

Yeah. Buy him an electric chainsaw. Some people just weren't made to use gas powered tools.

 

[FourMoCajuns]

Yeah. Buy him an electric chainsaw. Some people just weren't made to use gas powered tools.

I didn't want to say it but you are probably right. He is quite mechanically inclined but with chainsaws he.... well lets just say he has bad luck.

 

[CaseyForrest]

My inlaws just got an electric mower. Mechanical Engineer cant keep an internal combustion engine going for more than 3 or 4 years!!!

 

[buck futter]

Yeah. Buy him an electric chainsaw. Some people just weren't made to use gas powered tools.

Hahahaha

 

[FourMoCajuns]

Update

Buddy took the saw back to dealer where purchased and repaired. Upon inspection a small piece of plastic was found in the carb. Now my friend has never been into the carb so should this repair and the origional rebuild be covered under a warranty?

 

[Diesel JD]

I think it depends on if the dealer was into the carb or not, and if he is willing to own up to it if he was... Honestly I don't know if he has any legal obligation to fix this, I guess this is a question for Lakeside and Thall, knowing the rules for Stihl dealers and having a lot of real world experience. It would sure make me pretty loyal to a dealer if he'd stand behind his work like that though. The question is did the dealer cause this with a sloppy carb job, or did your friend cause it by running trashy gas....and if he did, how did plastic get into the carb from the tank?

 

[Lakeside53]

If the dealer wasn't into the carb after a rebuild, he should have been! Nobody rebuilds a saw that has seized without checking the carb... Well, almost nobody.

Press the dealer... but be polite - pissing contests go nowhere.

What does this "plastic" look like? Is it the sealer from the carb welch plug, or a foreign object? If it's from the plug, Stihl might honor the warranty... even years later. Hard to say though in this case.

 

[FourMoCajuns]

He said it looked like hardened PVC glue. I'm pretty sure the dealer discarded it though. I just hope they make it right for him. And to think this is the same saw that he wanted me to mod the muffler on. Jeez I am glad I didn't touch it!:jawdrop: