3.0 mercruiser wont idle in gear

[hellcat]

Hi first post. Will idle in neutral and can rev. but when you put it in gear it bogs and dies. runs and takes off fine if at cruise and full throttle. I think it might be a micro switch on throttle linkage but not sure can someone tell me what this switch does? thanx for looking i just want to be able to idle in no wake lol.

 

[fishrdan]

Re: 3.0 mercruiser wont idle in gear

The shift cut-out switch momentarily cuts the engine ignition while coming out of gear, nothing to do with idle quality.

The engine should idle at at 500-700 RPM in gear, so you should make the final carb idle adjustments when you have the boat in the water and idling in gear.

 

[hellcat]

Re: 3.0 mercruiser wont idle in gear

when it shifts into gear it dies. but it idles fine not in gear. it also seems like when in gear doesnt want to run under about 2500 rpm. also what pitch prop should i be running?

 

[JustJason]

Re: 3.0 mercruiser wont idle in gear

who cares about the pitch.... and only the boat manufactorer can answer that anyways.
You need to start with a full tune up and timing check... then move on to possible carb issues.

 

[Bondo]

Re: 3.0 mercruiser wont idle in gear

You need to start with a full tune up and timing check... then move on to possible carb issues.

Ayuh,.... Exactly...

 

[ziggy]

Re: 3.0 mercruiser wont idle in gear

can someone tell me what this switch does?

yep, go to the adults only sticky at the top of the i/o forum. open it and read #4. it'll explain it for you..

i'll concur with others, first thing to do would be a tuneup, by the book... don't know if you consider replacing fuel filters as part of a tune up. but i do. replace them too....

 

[hellcat]

Re: 3.0 mercruiser wont idle in gear

so everything should be tuned when in gear? if so ok, one more question bout tha switch why is it wired to the choke?

 

[JustJason]

Re: 3.0 mercruiser wont idle in gear

so everything should be tuned when in gear

A tune up is replaceing your sparkplugs, cap, rotor, wires is needed, points if applicable. All of your fuel filters. You have a fuel filter inside of the fuel pump and you may or may not have a fuel water seperator on a 3.0L (they don't come standard on a 3.0)
Then you run the boat (on the muffs is fine) and check and if necessary set the timing. Then check for proper timeing advance.
Then you put the boat in the water, start it and put it in foward gear, then set the idle RPM in gear, and double check the timeing and reset as necessary.
If your having a low speed issue, it still probably in your carb. But you have to make sure the boats in tune. You should do a compression test as well so you know what kind of compression you have. Especially on a 3.0, it's easy.