Hi Davie

Awesome, you think they will fit the Mariner 689? Had a few people said they wont? I can't see why they wouldn't as the engine is a yam. Also after a powerhead gasket kit to match. But happy to go with that if it will get it up and running : )

I had a quick check on these pistons and rings,

from yamaha £41.40 for each piston
£16.30 for each ring set
both + vat

Send a pm if you need them. Davie