Stihl MS251 wont start

[Marine93]

A friend of mine has a Stihl MS251 that died while he was cutting and will not restart. It gives a good spark off a new NGK plug.
Any ideas?

 

[zogger]

Pull off muffler, inspect for piston/cylinder damage.

 

[Marine93]

Pull off muffler, inspect for piston/cylinder damage.

Will do. Thanks!

 

[Oleo-Mac 999]

Good night, my old boss had a 250 or 251 no longer remember well that after having worked and if for any reason stop the engine, then it was a problem back to work. It has been several times to the store where it was purchased for them repair the engine and came always the same, was right from new with this problem. It is a problem of origin of this engine I see.

 

[zogger]

Will do. Thanks!

Welcome, it's what we do here.

Yep, just find out first. If it has scored, etc, it won't make enough compression to start. Just part of a normal checklist. Find out, then go from there.

 

[Marine93]

Update on the saw after a very busy Easter weekend.
Got the saw taken down and cleaned up. Pulled the muffler and noticed that the piston has a chunk missing off the edge closest to the exhuast port. The lower ring is scored and the top ring has some pretty bad wear marks on it. Looks like it didnt have enough oil mixed in.
So this brings the next question; Any ideas on how much a rebuild kit costs?

 

[Oleo-Mac 999]

If you look at ebay.com will surely find cylinders and piston for your chainsaw

 

[Marine93]

Found a piston and rings, but no cylinder that is any better on fleabay.

 

[Oleo-Mac 999]

We hope that appear here someone who knows the cylinder MS 260 gives the MS 251.

 

[zogger]

Well, adventure time. If you can do a pressure/vacuum test first, to make sure no air leaks, that would be good. then you can disassemble it, check and see if the cylinder is worth restoring, as long as no huge gouges out of it. Need to clean the crankcase out good too and inspect bearings, "chunk of piston" doesn't sound good. There is a possibility just the new piston will be enough, if the cylinder just has aluminum transfer you can sand off.

Stuff like this and me stuck with a single baby saw as my one saw plan after the tornado smashed us..more than one saw now..just a few..;HAHAHAHAHA!

 

[Marine93]

Thanks for the suggestions!

I have been bit by faulty parts on my Husqvarna. Hence the reason for my new Echo.

 

[Oleo-Mac 999]

You can not MS 251 has 30mm stroke and MS 261 has 32mm stroke.