1994 mariner nock

[gnfishn]

Hey guys,

I was having some issues last fall before I stored the boat. This started late summer. My motor didn't to want to idle very well when it was cold and smoked something terrible when I cracked the throttle. That I guess I could deal with but when it accelerated there was a nasty nock coming from coming from under the hood that went away after it warmed a while. I'm wondering how serious this might be. Would a rod nock go away after the engine warms? Should I just buy a new boat? Any insight would be great! Thanks

[boatfixer]

What hp?

Usually rod knock shows up after warm up. Piston slap will show up cold then go away when warm.

Have you done a compression test?

[walleyemaniac]

Carbon build up on the rings maybe. I have an older Yamaha 90hp that was doing the same thing but not a very bad knock just a little chatter. Started using this stuff from Yamaha called Ring Free Fuel Additive and it cure my problems (smoke, rough idle, and chatter) after a couple strong doses. Don't know if Mariner makes anything like that or reccommends it. This stuff was reccommended to me and it worked.

If thats not it I'd say maybe a wrist pin. I'm not a boat motor mechanic just from past experiences with 2 stroke motors.

[gnfishn]

The motor is a sixty HP. I haven't really done anything to it, other than trying to isolate the location of the knock, since it started later last year and it's still in storage now. It sounds like the easiest thing to try now would be the compression test. If a cylinder is low I probably have a big bill on the way. Maybe I'll get lucky and I'll able to cure it with the additive.

[raymondk]

Could be a leaking intake gasket i had the same thing happen to me last year sounded like a squeaky knock .