Idles great, bogs out under load. 115hp 2+2 Mariner

[John Drazic]

1988 115 2+2 mariner, 1st run of the season, cruised out of harbour great, when throttle advanced it runs rough and won't speed up. Fresh gas and my Yamaha kicker on the same fuel tanks ran great.Going to clean plugs and carbs, check for spark, any other advice appreciated.

 

[galamb]

You are on the right track there.

Do your spark check to rule out the ignition and I would change the plugs if they are more than a couple years old (outboards are "gas pigs" to start with and plugs are relatively cheap - I personally believe that you get better gas mileage out of newer plugs even if "old" one are still fine)

My bet would be the carb(s) - hopefully just a good cleaning will do the trick - kits for these run almost 40 bucks a piece and you would need 4 of them...

 

[John Drazic]

Thank you for these suggestions, if I wind up needing the carb kits, can you tell me what's involved and skill level required?

 

[faztbullet]

Also check that the accelerator pump as stronger output and lower injectors are clean and pop off under pressure....

 

[Docksidemarineservices]

Do not mix up your carbs. The engine only runs on two cylinders at idle and the other two kick in off idle.

 

[galamb]

Yes, the four carbs have different jets, so use some numbering system to keep them straight.

Skill level (?) - tough question to answer. Once off the motor I can rebuild a carb in about 10 minutes (that's 1 hour labour - thank-you )

It can be daunting if you have no mechanical experience, but it really isn't that difficult.

I would get ahold of a Seloc's manual for your motor (not Clymers). They run about 35 bucks but it will walk you through the entire process, with lot's of do's/don't hints thrown in for the casual user. You don't need much more than a socket set and a couple of screwdrivers to pull, rebuild and reinstall carbs - so if you even recognized the tools I mentioned, it's within your means

(p.s. - to compare, if you took them into a shop you would be looking at about 750 bucks for the rebuild - 200 for the first carb, 150 for each after that, plus parts - the manual is waaaay cheaper)

 

[racerone]

Search on ------you tube------Some very good videos that may be confidence builders for you.

 

[John Drazic]

Appreciate the advice, the weather is fantastic and the water is flat calm, very rare for these parts this early so no shortage of ambition!