Olympyk 980 Woods Port

[nicksterdemus]

I kinda jumped on board of Mntgun's thread coz there isn't a whole lot on the Olys & he had a lot of good stuff on his mod.

I didn't figure he would mind.

According to JD the CS71 & CS81 are different by 2MM bore & 2MM stroke.

So, you should be able to put a 81 jug on the 71 and split the difference for a 76CC, if I'm not mistaken.

I don't know if anyone makes a bigger bore than 52MM, but maybe some of the old hands will pitch in & throw us new meat a bone...

 

[jerrycmorrow]

mtngun,

When I saw your thread title, I couldn't get here fast enough. After some other saw projects are done, I'm thinking that my 970 will be next for some mild porting...if the other projects work out and I feel confident enough. I'll be following this thread with interest and it will be bookmarked.

Kevin

thinking bout a 970. what you think?

 

[jerrycmorrow]

nicksterdemus, this is my 970 as I got it back in March of 2006. I don't have any recent pics of it but it is basically in the same condition.

It pulls 185psi on what I would figure to be the original piston and rings. When I do run it, it usually wears a 20" bar and I have a 24" bar for it also. I was having troubles starting it lately, but come to find out that the choke wasn't closing properly because of the way the carb manifold (from the air filter) was fitting. As mtngun posted (post #82 in this thread) the new version is designed different and should take care of my problem...whenever I get it ordered. Right now the 044 is my go-to saw between the 2 (both being in the 70cc class). I have 2 brand new 20" chains that I'm saving for a comparison between the 044 and 970. The only minor mod to the 970 is on the inside of the muffler. The 044 has a slightly modded DP muffler cover and I reduced the squish to .023" (970 has a squish of .027" stock). Also the 044 has a Bailey's piston (I rebuilt it on a budget when I got it...if I need to, a Meteor piston will go in it next). I just have to find the time to do the comparison. I don't need 2 70cc saws, so eventually I plan on selling the 970 to help fund a 90cc class saw...but it'll be awhile before that happens...too many financial irons in the fire. I've said it before, the 970 is a pro built saw and a good runner. I envy the 999 owners .

Kevin

kevin,
looks like nicksterdemus got first dibs on your spare 970. i'm in the market and might be interested if he passes.

 

[jerrycmorrow]

The woods ported 980 is up and running ! ! !

Caber rings gapped 0.011" and 0.012". I believe this "C" jug is a bit oversize, hence the larger than normal gap. Still an improvement over the old rings.

I had no choice but to reinstall the world's wimpiest wrist pin clips, since no other kind of clip appears to fit.

The homemade paper gasket got a light coat of hylomar. I like Hylomar for this because it has a long set up time, so I can work at my usual leisurely pace.

The cylinder bolts were secured with a dab of blue loctite.

Intake side going together.

A new boot from Baileys. The old boot had shrunk and become stiff and was not sealing worth a hoot. The new boot is a different design that is secured by bolts and can't go anywhere. I highly recommend upgrading to the new boot.

i really enjoyed this thread mtngun. scuse the question but when working on large engines it was always stressed to torque the bolts. are you not torquing the cylinder bolts. if not, how do you determine how tight to twist?