Mercarb bogging, hard start

[MTBoat]

This 84 mercruiser 140 had a "rebuilt" carb put on last year and I adjusted the throttle llinkage to specs and other areas of concern by the book.

The engine runs beautifully and sounds great.

But, if you don't hold your mouth just right when starting (usually just a little extra throttle) it'll try to start and then not. Then good luck. Without a little starting fluid it just won't fire up.....but,,,when does,,,,runs great.

Second point is that when throttling up quickly as in skiing, it will bog and want to die, if throttled slowly all is well.

Anyone have experience with these two symptoms, which, I assume are probably related to the same need or fix?

Thanks

 

[Bondo]

Re: Mercarb bogging, hard start

This 84 mercruiser 140 had a "rebuilt" carb put on last year and I adjusted the throttle llinkage to specs and other areas of concern by the book.

The engine runs beautifully and sounds great.

But, if you don't hold your mouth just right when starting (usually just a little extra throttle) it'll try to start and then not. Then good luck. Without a little starting fluid it just won't fire up.....but,,,when does,,,,runs great.

Second point is that when throttling up quickly as in skiing, it will bog and want to die, if throttled slowly all is well.

Anyone have experience with these two symptoms, which, I assume are probably related to the same need or fix?

Thanks

Ayuh,... #1 sounds like ya gotta give it more throttle,....

#2 says the accelerator pump ain't givin' a big enough shot of fuel,..

 

[MTBoat]

Re: Mercarb bogging, hard start

Yes, tried the more open throttle, and/or pumping ahead of starting and it never works. At idle or very slight throttle it will almost always fire, but sometimes run, sometimes die and won't start after.

The bogging, some mechanics mentioned a possible accelorator pump as a possible too, guess my "rebuild" was not so "rebuilt". May need new. Can't think of any other reason its struggling,,,just not getting fuel when needed it seems.

 

[Bondo]

Re: Mercarb bogging, hard start

Yes, tried the more open throttle, and/or pumping ahead of starting and it never works. At idle or very slight throttle it will almost always fire, but sometimes run, sometimes die and won't start after.

The bogging, some mechanics mentioned a possible accelorator pump as a possible too, guess my "rebuild" was not so "rebuilt". May need new. Can't think of any other reason its struggling,,,just not getting fuel when needed it seems.

Ayuh,.... I Agree,.... Is the rest of the fuel system up to snuff,..??

 

[MTBoat]

Re: Mercarb bogging, hard start

Actually, I am not sure.
Could it be a weak fuel pump?
I have never known how to test that unit, or if it would cause such symptoms as described?