What happened ? Seized 056 mag

[Honest John]

Today I was working on a 056 magnum. Saw was very dirty. Initially, it had no spark but after removing the Bosch ignition and using heat shrink on the kill switch wire I was able to get spark. Also noticed that the saw would not make a full rotation, so I pulled the jug. The top of the piston had a lot of carbon buildup and so did the top of the jug. No major blemishes.

I poured mix into the crankcase to rinse it out and blew it out with compressed air. When I reassembled I noticed the saw was rotating just fine.

Once I put on a good carb the saw ran fine for a short while and then while coming off of throttle just seized.

I just pulled p& c and they look great but the crank is not rotating at all.

Any thoughts ? Just want to learn from this.

John

 

[huskihl]

Coil slid back over hitting the flywheel?

 

[Guido Salvage]

Bearings?

 

[CoreyB]

I have heard of things blocking the flywheel such as a backed out screw.

 

[t4driller]

Recoil came apart??

 

[Honest John]

Well I still don't know. Most likely it had something to do with the flywheel because once I removed that it started turning freely. There were no loose screws or anything and the screws for the coil were still in place too. I was able to get it going again after that for a while, and even though it needs a carb rebuild it was running pretty well and then it lost spark. I'll have to go back through my kill switch wire repair and make sure it's not shorting out somewhere.

The good news is I'm getting really fast at assembly on these !

 

[CoreyB]

Well I still don't know. Most likely it had something to do with the flywheel because once I removed that it started turning freely. There were no loose screws or anything and the screws for the coil were still in place too. I was able to get it going again after that for a while, and even though it needs a carb rebuild it was running pretty well and then it lost spark. I'll have to go back through my kill switch wire repair and make sure it's not shorting out somewhere.

The good news is I'm getting really fast at assembly on these !

That sounds like good progress to me!