j_franich
ArboristSite Lurker
Back in 2006 I purchased a box of John Deere CS71 parts off of eBay, the saw had consumed a circlip and destroyed the cylinder. It was being used commercially and was over a year old so it was no longer under warranty, I'm pretty sure I gave $75.00 for it. Well life happened, I moved to AK and sold the saw to my buddy. This fall I moved back to MI and ended up getting the saw back in the same condition I left it (just covered in more dust). Not wanting to spend a lot of money on this saw I ended up buying a used Olympyk 970 cylinder with a lot of aluminum transfer on it for $40, it looked to be the same minus the compression release. Some muriatic acid, sand paper and a Mako piston (not impressed) and I'm almost in business. I did some work with the dremel and widened the exhaust enough to leave 2mm of piston skirt on either side, widened the intake a bit and did a little grinding on the transfers.
I received my degree wheel this week and decided to see where this saw at, hopefully the numbers I have gathered make sense:
161 degrees Exh dur
145 degrees Int dur
19 degrees blowdown
.026" squish w/ homemade gasket
170 psi compression w/o having been started
If my porting timing numbers look legit(first time w/ a degree wheel on a saw), I would like to know from those that have successfully ported these saws if I am headed in the right direction.
I'm still waiting on a few small parts from Bailey's so I won't be able to start the saw until later in the week.
Thanks for taking a look!View attachment 277181View attachment 277182
I received my degree wheel this week and decided to see where this saw at, hopefully the numbers I have gathered make sense:
161 degrees Exh dur
145 degrees Int dur
19 degrees blowdown
.026" squish w/ homemade gasket
170 psi compression w/o having been started
If my porting timing numbers look legit(first time w/ a degree wheel on a saw), I would like to know from those that have successfully ported these saws if I am headed in the right direction.
I'm still waiting on a few small parts from Bailey's so I won't be able to start the saw until later in the week.
Thanks for taking a look!View attachment 277181View attachment 277182