Mariner 115 rebuild set-up

[thinksun]

My 1986 Mariner 115 inline 6 was down on compression on good old #3 cylinder. I pulled the block and have it being honed and will install one new piston and all new rings for each cylinder.

My question is which set up mod or combinatin of do I use. Mid and premium fuel is not as available as it once was at the local marinas.

1. install 76 main jets from 72 stock (quicksilver upgrade kit)

2. retard timing from 21 to 18?

3. machine high dome pistons to low dome profile (lower comp). The difference is .050" off of raised piston crown.

Any help is much appreciated.

 

[AMD Rules]

Re: Mariner 115 rebuild set-up

What is the serial number? A failure of #3 is typically a timing related event.

It should run fine on standard fuel. Use a good quality TCW-3 oil, such as Mercury's own brand.

Timing should be 20? max (cranking speed at WOT)

Main jets should be .074" for elevations up to 2500ft

That motor should have had low domes in it from the factory if it is a 115hp.

Check to make sure the bleed restrictors are all there (5 of them), under the intake covers.

Might want to consider removing the idle stabilizer if not already done so. They can effect timing in a negative fashion.

Consider plugging off the back drag crossover tubes on top of the carbs. A small BB fits well.

Good luck.

 

[thinksun]

Re: Mariner 115 rebuild set-up

The serial by memory is A940573. I will do the bb trick on crossover tubes and 74's while I tear into carbs (carbs look clean).

The bleed restrictors are intack, sadly the motor has less than 4 hrs on it from new- looks like it was just uncrated.

Do I just unhook the stabilizer?

thanks for the quick responce.