Planet Minis

mikemay · 03-10-2009, 08:26 PM

Z50R 1984

I just measured the end gap of my rings in the cylinder(end gap) I inserted the rings 3/4 inch down the bore top and bottom of bore. Here are my numbers I am not sure what they should be but they seem way off I think. I also measured the ring-to-groove clearance they also seemed wacky.

First Ring

End gap top of bore = .025 in
End gap bottom of bore = .024 in
First Ring(top ring) groove clearance = .005 in

Second Ring

End gap top of bore = more then .025 gauge to small around .033
End gap bottom of bore = more then .025 gauge to small around .033
First Ring(top ring) groove clearance = .0015 in

What should they be?

With all this being said I guess my bore is .001 out of whack from top to bottom is this a real bad thing or not that bad?

Could I just buy a new ring set and install them without honing cylinder bore as long as I set the end gap?

Thanks
Mike

LoudFastUgly · 03-10-2009, 08:54 PM

Quote:

Originally Posted by mikemay

Z50R 1984

I just measured the end gap of my rings in the cylinder(end gap) I inserted the rings 3/4 inch down the bore top and bottom of bore. Here are my numbers I am not sure what they should be but they seem way off I think. I also measured the ring-to-groove clearance they also seemed wacky.

First Ring

End gap top of bore = .025 in
End gap bottom of bore = .024 in
First Ring(top ring) groove clearance = .005 in

Second Ring

End gap top of bore = more then .025 gauge to small around .033
End gap bottom of bore = more then .025 gauge to small around .033
First Ring(top ring) groove clearance = .0015 in

What should they be?

With all this being said I guess my bore is .001 out of whack from top to bottom is this a real bad thing or not that bad?

Could I just buy a new ring set and install them without honing cylinder bore as long as I set the end gap?

Thanks
Mike

Don't have the book for your year, but for an 82 it's .004 to .012", service limit is .020" for the top and second ring.
No gap given for the oil ring.

Top and second groove clearance is .0004 to .0018", service limit is .005"

What's your bore diameter? Service limit is 39.05"

mikemay · 03-10-2009, 09:03 PM

Ya That right I think for a 84 also thanks.

I guess now the question is can I just put some new ring on and be good to go? or is it more complicated then that

mikemay · 03-10-2009, 09:06 PM

What's your bore diameter? Unfortunately I have no bore gauge is there a cheap way to check it because I am kind of poor right now

Thanks
Mike

LoudFastUgly · 03-10-2009, 09:20 PM

I've been kinda poor for the first 34 years of my life...

What's your piston diameter at the skirt?

mikemay · 03-10-2009, 09:27 PM

Quote:

Originally Posted by LoudFastUgly

I've been kinda poor for the first 34 years of my life...

What's your piston diameter at the skirt?

Have no Idea I guess I got to return the empty beer bottles in my garage and go buy a caliper and micrometer LOL

Thanks again for the help

LoudFastUgly · 03-10-2009, 09:30 PM

Quote:

Originally Posted by mikemay

Have no Idea I guess I got to return the empty beer bottles in my garage and go buy a caliper and micrometer LOL

Thanks again for the help

Don't let go of your retirement fund so quickly! Lol.

What brought you to this level of detail? Compression no good?

mikemay · 03-10-2009, 09:37 PM

AH I took it apart(open a can of worms up) and notice the rings looked really bad. I think I might just get some new rings install them and then ride the motor till the top end goes bad then upgrade to a 88cc TB head and cylinder kit. I think this might be the best option for me for now.

Also I think I was getting oil in the combustion chamber

Thanks

03-10-2009, 08:26 PM	#1 (permalink)
mikemay PM Newbie Join Date: Feb 2009 Posts: 73	Piston Ring End Gap Groove Gap Z50R 1984 I just measured the end gap of my rings in the cylinder(end gap) I inserted the rings 3/4 inch down the bore top and bottom of bore. Here are my numbers I am not sure what they should be but they seem way off I think. I also measured the ring-to-groove clearance they also seemed wacky. First Ring End gap top of bore = .025 in End gap bottom of bore = .024 in First Ring(top ring) groove clearance = .005 in Second Ring End gap top of bore = more then .025 gauge to small around .033 End gap bottom of bore = more then .025 gauge to small around .033 First Ring(top ring) groove clearance = .0015 in What should they be? With all this being said I guess my bore is .001 out of whack from top to bottom is this a real bad thing or not that bad? Could I just buy a new ring set and install them without honing cylinder bore as long as I set the end gap? Thanks Mike Last edited by mikemay; 03-10-2009 at 08:37 PM.

03-10-2009, 09:03 PM	#3 (permalink)
mikemay PM Newbie Join Date: Feb 2009 Posts: 73	Re: Piston Ring End Gap Groove Gap Ya That right I think for a 84 also thanks. I guess now the question is can I just put some new ring on and be good to go? or is it more complicated then that

03-10-2009, 09:06 PM	#4 (permalink)
mikemay PM Newbie Join Date: Feb 2009 Posts: 73	Re: Piston Ring End Gap Groove Gap What's your bore diameter? Unfortunately I have no bore gauge is there a cheap way to check it because I am kind of poor right now Thanks Mike

03-10-2009, 09:20 PM	#5 (permalink)
LoudFastUgly 2nd Gear Member Join Date: Aug 2008 Location: GTA, Ontario, Canada Posts: 383	Re: Piston Ring End Gap Groove Gap I've been kinda poor for the first 34 years of my life... What's your piston diameter at the skirt?

03-10-2009, 09:37 PM	#8 (permalink)
mikemay PM Newbie Join Date: Feb 2009 Posts: 73	Re: Piston Ring End Gap Groove Gap AH I took it apart(open a can of worms up) and notice the rings looked really bad. I think I might just get some new rings install them and then ride the motor till the top end goes bad then upgrade to a 88cc TB head and cylinder kit. I think this might be the best option for me for now. Also I think I was getting oil in the combustion chamber Thanks

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