Chainsaw Repair

Converting a Dolmar 111i from a open port cylinder and non window single ring piston to a closed port Dolmar 115i closed port cylinder and a Meteor double ring window piston. 

I was in the process of converting my Dolmar 111i to a 115i with the addition of a closed port cylinder from one of my model airplane engines. I have already changed the clutch over to the wrap coil spring clutch of the 115 and changed the rim over to 3/8" X 7 pin and have a 59 DL 16" bar on it. I also put a new 3.4mm  double braid pull cord in the starter. I would like to make note here that the very last 111i's made had closed port 44mm cylinders and window pistons from the factory just like the 115i.

The cylinder is a used one that is in nice shape. It also has a Mahle single ring piston.

I originally intended to clean up a straight gassed cylinder I had but decided to use the cylinder from the model airplane engine. I bought a Meteor 44mm 2 ring window piston form the Israeli for $35 incl shipping. It has the same squish height as the OEM Mahle window piston but the Meteor is domed. It also has a short skirt. The Meteor is a nice piston except for the skirt that is about 1 1/2 mm short. As a result, it free ports about .010" about half way across the bottom of the exhaust port. Essentially just enough to say it free ports!

Some people like Neil Murphy proclaim that this small amount free porting will not hurt anything? What do you think about the free porting?

I cannot understand why Meteor pistons have the short skirts?

I also noticed that both rings of the Meteor piston come down into the intake port port but the pins do not show. On the OEM piston, the single ring also completely shows in the intake port. I would like to use the Meteor piston because it is new and has the dome and more intake timing but I don't like the two rings instead of one and I don't like the short skirt.

I can just use the OEM Mahle piston which does not free port? I like the idea that it is single ring but it is flat top.

Thanks

it's never a good idea to do that. bad infact. totaly different can of worms.

  yeah i have one of them 'temp toofs'. waiting on the infection to totaly clear up and the root to heal, or something like that. i wasn't listening as i  was enjoying the non pain at that moment mine has a small area where there is a little pressure point that wasn't there before, but i can live with that. pure heaven compared to before.

do the top ends from the 115 bolt on directly? never been into a 115. lots of 111's, have one myself. and it's a good saw. but you know. always looking for a little more ooomph.

  great. now i'm going to have to find a good 115 topend. juuuuuust great.