Ariel Owners Motorcycle Club

Ray - did you have any joy finding a suitable replacement piston? I'm looking too now.

Hi Tony. The only source of repro piston I could find is JP. They appear to have standard up to +40 sizes. The barrel I have is in pretty poor shape so I am still keeping an eye out for another with not so many broken fins to repair (yes, I know, good luck with that...). I am also remaining optimistic there are a few Hepolite 1109s out there still waiting to be discovered.

I'm going to try to rescue my standard piston - the top groove has spread a little so the clearance now is causing rings to break - I'm going to widen it a tad and get a wider ring made to fit. If not it'll be rebore and JP. I'll keep an eye out for 1109 pistons.

You can put two rings in the widened groove. Works fine. Nev

nevhunter wrote: Tue Sep 24, 2024 12:30 am You can put two rings in the widened groove. Works fine. Nev

Its been running for ten years with two 1/16" compression rings in the top groove, but after an `episode' it appears to have spread the groove a little so there is too much play now and its breaking rings.

It won't wear the groove any more than with a single ring. Carbon in the groove or not enough end gap breaks rings. SV motors run very hot especially near the exhaust port. A "twisted" con rod will make the rings wear more and having no air cleaner. Nev