Jump to content

440cc kit ring gap spec?

Recommended Posts

what should the ring gap be on a 440cc kit? i received a 440cc cylinder kit from ebay, but it didnt come with anything specifying a ring end gap or which rings go where. im pretty sure that the silver ring goes on top, the black ring second with the markings up?

Share this post


Link to post
Share on other sites

Without any literature for the new kit, I think I'd use stock specs.

So, For the top ring, the middle of the ring end gap spec for stock bore is .011". Stock bore is 3.346. 

.011" / 3.346 That comes to .0032" per inch of bore. So multiply .0032" x your 440 bore(in inches) to get ring end gap for the 440.

So, middle of the gap spec for the 2nd ring is .017" and middle for the oil ring is, say .011".  Do the same calc for them.

 

Capture.JPG

Edited by Trailryder42
  • Helpful 1

Share this post


Link to post
Share on other sites

I got. 017 on the silver ring which im guessing is the top ring, and. 013 on the black ring that has a ridge on the underside, so im guessing the black one is the second ring. Going by stock specs per inch of bore, the top ring is a little out of spec and the second is under spec. But if there were switched, the specs would line up. The oil rings are right at. 015, so a smidge under the middle of spec but still in there. Whats your thoughts? Is the silver the top or second ring? 

IMG_20200709_185441.jpg

Edited by 96xr

Share this post


Link to post
Share on other sites

judging by this video, it looks like the silver is the top ring because it is chamfered on top and bottom slightly. so im thinking i'll just gap the lower one to about the same as the top and call it good.

Share this post


Link to post
Share on other sites
4 hours ago, 96xr said:

judging by this video, it looks like the silver is the top ring because it is chamfered on top and bottom slightly. so im thinking i'll just gap the lower one to about the same as the top and call it good.

How are you measuring end gap, like in this video?

 

Edited by Trailryder42

Share this post


Link to post
Share on other sites
7 hours ago, Trailryder42 said:

How are you measuring end gap, like in this video?

 

yep, lettering up, using the piston to make sure the ring is even in the bore than measuring with feeler gauges. i have both rings set to about .017 now. i figure its better to have the tolerances a little loose here rather than too tight so it doesnt seize up. the second ring is in spec, and the top ring is under the service limit, so it should still be good to go.

  • Like 1

Share this post


Link to post
Share on other sites

just a little update, finally got to hear her run again after sitting for about 8 years! she is badly in need of some tlc, but she LIVES AGAIN! just a bunch of little things that add up to a lot to get her into a livable state, but she breathed fire tonight! i am SO EXCITED to ride her again!🤩

  • Like 1

Share this post


Link to post
Share on other sites

this is how she was sitting in my barn for the past 8 years with a bag over the crankcase. and after $200 in parts for a 440cc cylinder/piston kit and valves, she lives again!

069.jpg

  • Like 1

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Reply with:


×
×
  • Create New...