Missing piston ring locator pin

I was working on installing a 44mm Airsal kit onto my A3 Tomos tonight when I noticed this. The locating pin for the lower piston ring appears to be missing. The black circle you see in this pic is the hole for the pin, but the pin itself is nowhere to be seen (the pin for the top ring is there)

I've never seen this happen, but boy am I sure glad I checked. Guess I'll run it with just one ring until I can get a replacement. (edited)

PXL_20210228_045246281.jpg

Re: Missing piston ring locator pin

While the piston is out and in hand , you might consider installing a compression pin .

I pinned the piston of my '57 Simplex using 1/4" long x 3/32" wide compression pins .

I drilled the landings to a depth of about 5/32" . The pins had to be driven in , so it's unlikely that much , if any, outward drift will happen . I used a jewelers square file to square the outer end of the pins and the ring ends , which needed relieving to fit the pins . Then , they were 'good for service' .

That was 5 years ago . Those pins haven't moved an iota , since . ;)

Re: Missing piston ring locator pin

That's a good trick. I was pondering how to replace it today.

« Go to Topics — end of thread

Want to post in this forum? We'd love to have you join the discussion, but first:

Login or Create Account