Chainsaw Top End Rebuild
Have a trashed chainsaw? Father-in-law is 84 and doesn’t see so well any more…don’t know what he put in the fuel tank but is sure scuffed the cylinder walls and piston to the point where the saw wouldn’t run any more.
A 20-year-old Stihl 026 Farm Boss worth maybe 250 bucks….not economically repairable at the saw shop. But I did find a NOS Stihl top end rebuild kit on Ebay for 50 bucks, a gasket set for 8 bucks and a service manual for another 8 bucks so for that amount it was worth doing. These rebuild kits are $135-150 retail from Stihl.
The new cylinder was the newer type with the compression release. Couldn’t find one on-line so I go see Howard at Belfair Power to see if he had an old trashed cylinder with one still in it I could recover. He didn’t, but pointed out that the new piston in my rebuild kit was no higher compression than the original, and that I could live without the release. He didn’t have the special bolt to plug the hole, so I hit the hardware store for a machine bolt and copper washer I could grind to fit…which I did.
Dismantling the saw to expose the cylinder, I discover all the machine screws are Torx headed. I’ve got those for all except the long-reach Allen-style wrenches needed for the cylinder head-to-crankcase screws, but I discover a 9/64†Allen will break them loose without damage so I proceed. You can see the wrench reaching thru clearance holes in the cylinder fins to get to the machine screw in the pic above.
The hose clamp on the rubber intake manifold is loosened and the cylinder head pulled from the saw…
The shiny new piston is fitted to the connecting rod using the old spring clips…everything lubed with 90wt oil and swab…
The rings aligned per the book and compressed with a hose clamp…a new crankcase gasket installed…
And the new cylinder…also liberally lubed…tapped on, displacing the hose clamp which is dismantled and removed.
The cylinder screws are replaced and torqued, and the spark plug is grounded to check for spark with a pull of the cord before installing the plug.
The carb, which had been washed in carb cleaner and had been soaking in solvent, was reinstalled with it’s linkage and a new gasket…fresh fuel added after cleaning out the tank and filter…and she fires on the 3rd pull and both runs and idles well…I got lucky for a change.
Shrouds, handles and covers reinstalled, and Pop has a working saw again….only this time…I’ll supply 5 gallons of correct fuel so he doesn’t run out.
$66.00 and about 2 hours…as opposed to ever $300 at the saw shop.
“When we build, let us think that we build forever. Let it not be for present delight nor for present use alone. Let it be such work as our descendants will thank us for; and let us think…that a time is to come when those (heirlooms) will be held sacred because our hands have touched them, and that men will say, as they look upon the labor and wrought substance of them, ‘See! This our father did for us.’ “ –John Ruskin.
Replies
Thank you, Bob.
I love to see a good tool refurbished instead of just thrown out. And the cheaper the better, as long as the quality of the tool doesn't suffer.
Good job.
It's been time for a long time, for me to do a real rebuild on my chainsaw. I have to use starter fluid to start it the first time, every time. After it is warmed up, it will start and stop like a charm.
Live, Love, Forgive and Forget
quittintime
Yo Bob...wanna try a '66 homelite?..Had a chip put in ignition (by a repair shop) still takes 6 -10 pulls cold start..and LOUD..geez the airport calls me to say "knock it off" we can't hear anything!