026 build ?'s

[racin69z]

I have a 026 that is a 1996 model. It was my high school graduation present from my parents. It probably hasn't been used 40 hours since new. I was reading on here the other day about chains, and one thing led to another and now I have the saw apart on the bench to work on the motor. I guess the gearhead in me has taken over.

I plan on doing a mild port and a muffler mod.

I have built a couple of two strokes (atv and outboard motor), but never a Saw.

I noticed on the exhaust port side of the piston and jug there are some wear marks. No aluminum transfer on the cyl bore, just smooth wear lines running up and down the cylinder that you can feel and see. I didn't think of checking compression before I took it apart, so I will do that tonight when I get home.

One thing that I noticed, the exhaust side of the piston crown is hitting the squish band in the cylinder. It has the top ring pinched just a little in the ring groove. I am going to try and dial indicator the rotating/reciprocation assemblies tonight to see if there is excessive wear/play in any of the bottom end to explain that.

Is there any kind of online reference that may have torque specs and acceptable tolerances for this engine?

Is my saw considered an old 026? Will the muffler mod be similar to the newer saws?

When you guys run without a base gasket to gain compression do you use anorobic (I think thats how its spelled) sealant between the crankcase and the jug or something else? Thats what I used on the outboard.

Thanks for any advice

Lynn

 

[racin69z]

I got back out to the shop and did some more checking on things.

I freed up the stuck ring and put the jug back on without a base gasket, it only had 75 psi of compression after about 6 pulls. It actually ran good before I took it apart. Its been a long time since the saw was new, but I don't remember it going down hill that bad. When I was compression testing, I could actually hear the piston hitting the squish ring in the cylinder. I assume it was piston rock at TDC due to excessive skirt wear on the piston.

I was wrong, there was aluminum transfer on the bore. I used muratic acid and 400 grit with soapy water to take care of that. The bore feels pretty smooth now, theres a little wear above the exhaust port, but it is very slight. Since this is my first attempt at a port job, I won't feel too bad if I screw it up.

So the plan ahead is for sure a new piston & rings, fuel line, impulse line, carb adapter, home ported cylinder, muffler mod, and maybee crank seals(don't know how yet).

Lynn