Honda-SOHC

SOHC.co.uk Forums => CB500/550 => Topic started by: petermigreen on April 09, 2017, 01:29:24 PM

Title: Piston Rings
Post by: petermigreen on April 09, 2017, 01:29:24 PM
Rather clumsily managed to break a ring during disassembly today. So obviously need to get a new set.
Question is this. Am I correct in thinking that if cylinders are on standard bore then the pistons will have NO numbers on the top surface?
Anybody got any sets?

Thanks, Peter.
Title: Re: Piston Rings
Post by: Bryanj on April 09, 2017, 01:38:41 PM
Pistons are not always marked with the size but the rings always are by the gaps usually with a letter on one side of the gap and numbers on the other. If no numbers its standard then 25, 50, 75 or 1.00.

Numbers/letters always face upwards
Title: Re: Piston Rings
Post by: petermigreen on April 09, 2017, 01:40:53 PM
Very helpful thanks, I'll clean them up and have a closer look, under a magnifying glass.
Title: Re: Piston Rings
Post by: petermigreen on April 09, 2017, 02:13:14 PM
Just an 'R' on middle ring. No markings on top rings does that mean they are non directional?
Thanks
Peter
Title: Re: Piston Rings
Post by: Trigger on April 09, 2017, 05:40:13 PM
Should be markings on the top ring, where did you get them from ?
Title: Re: Piston Rings
Post by: petermigreen on April 09, 2017, 05:55:53 PM
they came in the engine. I was under the impression they are the original rings. Maybe not.
Peter
Title: Re: Piston Rings
Post by: Trigger on April 09, 2017, 06:11:26 PM
Sorry, I assumed that you had broken a new ring. Fitting old rings is a false economy in my book, you will have to cross hatch the bores to get new rings to bed in.
Title: Re: Piston Rings
Post by: Bryanj on April 10, 2017, 06:41:35 AM
If they have been in a while there can be enough wear on the side to remove any light marking. R is a common one with nothing else means standard
Title: Re: Piston Rings
Post by: Seabeowner on April 10, 2017, 09:21:14 AM
Peter, I could not work on bikes without 6""digital calipers. They are pretty cheap, but maybe avoid the £5.99 variety. £20 would do it. Measure the max dia. of the piston skirt and even after a considerable mileage that should still be pretty close to the bore size.
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