Dam it! Wont Idle

[scatgo]

The engine is a 350 votex with what looks like a Merc 2 barrel carb. the engine is a rebuild with two seasons on it. Last year things were great with the exception or the RPM floating around a little. About + or - 200 RPMs. Ran great when I winterized it used fuel stabilizer.
Took it out for the first time this year and it will not stay running below 1200 RPMs. From past experience it looks like the idle circuit is clogged. I would like to take the idle mixture screw out spray some carb cleaner in it but Iam not sure how the idle circuit works. Many carbs I have worked on will have small holes in the barrel below the throttle plate and a mixture screw that will adjust air flow into the circuit or gas flow. Detailed information on how the idle circuit works will help a lot. Thanks

 

[Scott06]

Heres a video on it or the first one in a series showing rebuild.

usually if idle circuit is plugged it will idle low or wont idle… make sure the linakge is not hanging up. I would disconnect the throttle linakge and make sure throttle plates are returning against the idle speed screw, look for linakges hanging up

 

[dubs283]

I would like to take the idle mixture screw out spray some carb cleaner in it but Iam not sure how the idle circuit works. Many carbs I have worked on will have small holes in the barrel below the throttle plate and a mixture screw that will adjust air flow into the circuit or gas flow. Detailed information on how the idle circuit works will help a lot.

You can certainly do this but it probably won't solve the issue. Most likely you need to clean/rebuild the carburetor. A factory service manual can explain quite detailed how the carburetor works including rebuilding.

If you google marine rochester two barrel/mercarb that ought to give you some more info as well.

It's in your best interest to measure fuel pressure and vacuum along with a full tune up if it's been more than 2/3 seasons since service

 

[scatgo]

Thanks for the help but unfortunately now Iam dealing with eletrical issues that are keeping me from even starting the boat. Ill get back to you.

 

[scatgo]

Ok. here is where I am at the moment. New plugs cap rotor sensor fresh gas and no progress. It started raining the second i started the boat after all the work I did so i didnt get to look into things but it dosent look good. Looks like I have the same problem. It will run at high rpm but no idle. any suggestions would be appreciated. Thank you.

 

[scatgo]

You can certainly do this but it probably won't solve the issue. Most likely you need to clean/rebuild the carburetor. A factory service manual can explain quite detailed how the carburetor works including rebuilding.

If you google marine rochester two barrel/mercarb that ought to give you some more info as well.

It's in your best interest to measure fuel pressure and vacuum along with a full tune up if it's been more than 2/3 seasons since service

Any suggestions on how to measure vacuum?

 

[nola mike]

Ok. here is where I am at the moment. New plugs cap rotor sensor fresh gas and no progress. It started raining the second i started the boat after all the work I did so i didnt get to look into things but it dosent look good. Looks like I have the same problem. It will run at high rpm but no idle. any suggestions would be appreciated. Thank you.

Carb rebuild, as suggested in post #3

Any suggestions on how to measure vacuum?

Vacuum gauge plugged into a port on the intake manifold

 

[scatgo]

Carb rebuild, as suggested in post #3


Vacuum gauge plugged into a port on the intake manifold

Got it.

 

[scatgo]

Well that seems to have worked like a charm. Just put the carb back on and it purrs lick a kitten. Thanks