Merc 150hp V6 carbed/ idle problems sometimes

[shaneburris74]

Every once in a while when pulling up to the dock..jockeying from fwd to rev. the motor will die. Usually starts right back up. When I had it out last weekend twice it was a hard starter twice when shutting down at the dock and attempting to restart shortly thereafter (the motor was warm). It always started up, but one time I had to pull out the throttle arm and give it some throttle while in neutral to get it to kick off. I think this is a problem with the carbs/ fuel. Let me know if you guys agree.
And if so- I am not ready to tear into these carb's right now. I would rather wait till after the season (hopefully I have that choice). The problem is not consistent, 95% of the time it starts and runs great.
Is there anything I can do/ or should do as a temp. fix to clean up the carbs? Any kind of carb cleaner I should use? The seafoam stuff? If I have to tear em' down I will...just would prefer not to right now. Is there a carb rebuild kit out there I can get?
Thanks guys.

 

[j_martin]

Re: Merc 150hp V6 carbed/ idle problems sometimes

A little sea-foam in the fuel can't hurt.

The fuel pump should be rebuilt every coupla years. It could be getting a little weak, thus troubles at idle.

Also, if the idle is set real low and relying on an idle stabilizer module to keep it going, and the module is crapping out, it's die like that. Fix would be to remove the module and reset your idle timing, and possibly your WOT timing depending on the module.

hope it helps
John

 

[Barnacle_Bill]

Re: Merc 150hp V6 carbed/ idle problems sometimes

Yep, run some Seafoam thru it, get rid of the idle module, then do a link & sync.

 

[shaneburris74]

Re: Merc 150hp V6 carbed/ idle problems sometimes

Thanks bhile. The idle module has already been removed. It was gone when I bought the boat. I do have a shop manual. What exactly is a link and sync?
thanks again.

 

[Barnacle_Bill]

Re: Merc 150hp V6 carbed/ idle problems sometimes

Its the procedure for making sure your timing (high and low) is set correctly and all linkage is adjusted properly. You will also set your idle properly while doing it. The procedure is in your manual.

 

[Ed R]

Re: Merc 150hp V6 carbed/ idle problems sometimes

Hey, Re; Sync and link. Is the timing between when carburators open with the righ amount of spark advance. At idle carburator plates (throttle shutters should be closed running off the idle circuit of carburator). Idle timing should be anywhere from 2 to 8 degrees atdc. Once the motor idles lower than 500 RPM, the idle stabilizer would kick in and advance timing 3 to 4 degrees to keep idle constant.

Fuel is a big issue with all the added alcohol and methanol causing an uneven burn, (vapor lock when motor is hot).

ER