Re-Ring 99 60HP BigFoot

[bryancx94]

I've worked on 2cycle jetski motors for a long time. My friends outboard compression is reading low and he wants to rip the head off and possibly re-ring, bore, or sleeve the motor. How difficult of a job is it on this motor. It seems like you need to remove a lot of items to get to the heads. Is there any good manuals out there that walk you through this process? Current compression is 115/115/110, 99 Mercury 60HP BigFoot 3cyl 2cycle.

 

[Don S]

Re: Re-Ring 99 60HP BigFoot

Go to the link below, use the index to find the right manual, then download the OEM manual. That is about as close to a walk through as you are going to find, just remember those manuals were designed for Mercury trained techs, not DIYers.

http://forums.iboats.com/showthread.php?t=459535&p=3105186#post3105186

 

[Sunfish12]

Re: Re-Ring 99 60HP BigFoot

I would run Seafoam through it and recheck compression. That compression isn't to to low.

 

[robert graham]

Re: Re-Ring 99 60HP BigFoot

Those compression readings sound pretty good, is he having problems with the motor that would make him think of tearing it down for a rebuild? If it's running poorly then maybe check/clean carbs, fresh spark plugs, or other tune-up items....

 

[Silvertip]

Re: Re-Ring 99 60HP BigFoot

Assuming this is a two stroke, you don't get to the rings by removing the head. The engine requires total disassembly to do that. And why on earth would he even be considering a re-ring since those compression numbers are very acceptable. Why is it amatuers always aim for the most expensive, and usually the least necessary repair.

 

[vance14]

Re: Re-Ring 99 60HP BigFoot

I think you will find out that this engine does not have removeable heads.I have the mercury service manual and the engine is shown splitting at the crankshaft.So a rering is a total tear down.

vance

 

[1nebel0]

Re: Re-Ring 99 60HP BigFoot

I have a 60h.p and your numbers are fine.. At best it was 125...Sea Foam it and maybe the lower cylinder will come up along with maybe a few more pounds on the others..This motor needs nothing and tell your friend to spend his money elsewhere...Everyone above states it the same....

 

[Mi duckdown]

Re: Re-Ring 99 60HP BigFoot

Exactly. Ditto.