Question for Honda motorheads

[Chrisj CMA]

If rebuilding a Honda motorcycle engine and doing a simple honing and new OEM rings. Do you need to size them (end gap) or is that just for high performance after market rings?

[luftkoph]

If it's a nikasil cylinder,honing is a no no

[Chrisj CMA]

If it's a nikasil cylinder,honing is a no no

Ok but the question is about sizing OEM rings?

[da prez]

Will not hurt to check. You know there are never any manufacturing mistakes. Also , no hone.

                                 da prez

[Chrisj CMA]

Will not hurt to check. You know there are never any manufacturing mistakes. Also , no hone.

                                da prez

My neighbor is working on a 80's era Honda 650. I suggested he gap the new rings before installing. He says he never does when using OEM parts. He's already had the cylinders honed so if he shouldn't have it's too late

[h13man]

Gap/check them. I used new stock rings  and they had to be gapped after hone on a 73' XL250.

[Chrisj CMA]

Gap/check them. I used new stock rings  and they had to be gapped after hone on a 73' XL250.

Thank you. I didn't think I was crazy

[rug_burn]

Is there some rule of thumb as to how much to gap the rings?   Like some percentage of the diameter or circumference?

[h13man]

That info is in the OEM manuals which is the only source I would use.

[Firefight100]

You should definitely check ring end gap.  Don't assume the person packaging the rings cant make a mistake.  And there is a formula but best to use mfg specs.  Ring gaps specs vary depending on cylinder, piston and ring material.  As well as intended use.

[gordonv]

Will not hurt to check. You know there are never any manufacturing mistakes. Also , no hone.

                                da prez

My neighbor is working on a 80's era Honda 650. I suggested he gap the new rings before installing. He says he never does when using OEM parts. He's already had the cylinders honed so if he shouldn't have it's too late

OEM or not, I'm sure they weren't made by the OEM, and they should always be checked. But do you need to get them to a specific gape, or just not the ends in contact when compressed?

[Chrisj CMA]

Will not hurt to check. You know there are never any manufacturing mistakes. Also , no hone.

                                da prez

My neighbor is working on a 80's era Honda 650. I suggested he gap the new rings before installing. He says he never does when using OEM parts. He's already had the cylinders honed so if he shouldn't have it's too late

OEM or not, I'm sure they weren't made by the OEM, and they should always be checked. But do you need to get them to a specific gape, or just not the ends in contact when compressed?

It's a specific gap. Too tight and the ring breaks when hot. Too large and you loose more compression. Definitely more critical on the tight end but it's a fairly scientific process to do it right.