Honda-SOHC

SOHC.co.uk Forums => CB750 => Topic started by: yozzer74 on August 24, 2015, 09:43:40 PM

Title: Piston ring size
Post by: yozzer74 on August 24, 2015, 09:43:40 PM

I'm wanting to buy some new piston rings but how do you tell what size they are can't see any marks on pistons to see if there' standard or over size .??

Title: Re: Piston ring size
Post by: hairygit on August 24, 2015, 10:40:58 PM

If they are genuine pistons (hm stamped in the little depressd area where the gudgeon pin goes in) and no markings on the crown, they are standard size.

Title: Re: Piston ring size
Post by: yozzer74 on August 24, 2015, 10:59:39 PM

Thanks I will check that out tomorrow

Title: Re: Piston ring size
Post by: Bryanj on August 25, 2015, 08:22:14 AM

Check on the top surface of the rings, no markings mean standard or you see25; 50; 75; 1.00 or something very similar

Title: Re: Piston ring size
Post by: AshimotoK0 on August 25, 2015, 08:43:09 AM

I have also seen ART marked on OEM pistond and no HM logo. On twins models though.

Title: Re: Piston ring size
Post by: hairygit on August 25, 2015, 08:50:37 AM

Quote from: AshimotoK0 on August 25, 2015, 08:43:09 AM

I have also seen ART marked on OEM pistond and no HM logo. On twins models though.

Yes, I found  ART on my CB175 pistons, but the fours I have worked on tended to be HM, although the general rule seems to be even if pattern pistons are fitted, if they are standard size they have no markings on the crown, whereas oversize ones have the oversize stamped on the crown, and as Bryan said, the rings are often marked too, although some people fit oversize rings and file the ends to fit standard pistons, so the crown is the most reliable guide,