MS251 Issues

[toolmaker]

Gonna talk about two friends hare:

Friend 1: bought the saw 5 or 6 years ago. He's in his 70s' very little use on the saw. Maybe just a few gallons of fuel. He uses the pre-mix stull bought at box stores. Carb was replaced 2 years ago at dealer where he bought it. The saw locked up. Very bad scoring on piston and cylinder. Dealer said bad gas.

Friend 2: Retired OPE instructor at the school where I retired from. Has his own OPE shop. I took the saw to him. At friend 1 request, a new aftermarket jug and piston were installed. Saw fired up and ran and locked up. Tear down revealed the crank bearing came apart. New OEM crank bearing installed. SAw fired up and ran but shut off and didn't sound right. Tear down again reveals scratched piston and jug.

Friend 2 saws it's not worth throwing more money at it. there must be some damage that is causing a slight amount of misalignment in the guts somewhere.

Thoughts?

 

[Wood Doctor]

The only thing I ran into with the 251c that I own is that the saw tends to flood very easily when cold. On a fresh start, it will flood after three pulls and not let you know that it's ready to start with an unchoked pull. Other than that, it's a good runner, similar to the 025's that I ran and serviced for years.

I would say that you have and air leak somewhere that is ruining things. Lots of people have worked on your saw. Really a bummer when this happens.

 

[bogieboy]

on saw 1, potential air leak combined with box store premix did it in.... we have a 362 sitting here at the shop right now, put a new top end in after vac/pressure testing the saw, and they blew it up in a month, and they "only" use Trufuel 50:1... scored it so bad it wouldn't even start