85 mariner 90 hp wont run

[yjcrawler]

first of all thanks for takin time to help me....the boat motor runs "okay" with out being "in gear" idles okay mid throttle has a slight miss..wot..seems to scream...when you engage it into forward gear it runs okay untill you give it throttle..any amount..it stumbles and loads up ..misses ..it sounds like it is getting to much fuel..it had fuel running out of the carbs so i rebuilt the carbs...that fixed the fuel leak.... but still no luck with the running issue.. so i did a comp test...1..135 2...136 3...140 4...133 5...135 6...140 they all seem good to me.but i am not an outboard mechanic.. i did a search and found this dude..clams canino... seems to know alot so i printed off his timing and sync page...going to give that a try any body else have any ideas please let me know...this is my first boat and so far i really like it even though it runs like crap

 

[yjcrawler]

Re: 85 mariner 90 hp wont run

oh i put new plugs in it too still no help and i chaecked spark at all cyls good spark

 

[bigjack54]

Re: 85 mariner 90 hp wont run

I have same Engine Did just the same, Get the stator checked that was my fault. it was only running on the slow windings

 

[CharlieB]

Re: 85 mariner 90 hp wont run

Clams knows his stuff, follow his directions to the letter and your motor should be fine.

Bogging or hesitation on acceleration is often caused by improper idle fuel mixture.

Once the carb linkage and synch is done following Clams directions, the idle mixture must be adjusted ON THE WATER and while in Forward gear. Correct adjustment on the hose is very difficult as the exhaust back pressure is not there as it is once the boat is launches and water is in the exhaust passage of the mid-leg.

Idle mixture must be adjusted to BEST idle speed, plus almost an additional 1/8 turn further out which supplies the additional fuel necessary for crisp acceleration.

Fine adjustment can only be made while on the water, test acceleration by rapidly accelerating, testing your hole-shot, any slightest hesitation indicates a need for more idle fuel.

Additional load such as pulling up a skier will need even slightly more idle mixture.