Mercruiser 140

J

jikol

Cadet
Joined
Sep 24, 2012
Messages
7
I just took my boat out for the second time in two weeks. The first time I had no issues, but the last time was different.

Both times I had to pour some gas in the carb, but it started fine after that.
However this last time it would die as soon as I gave it any gas, but it would kind of run when just put in gear. I looked in the carb and i could seen a little gas and vapor when the throttle was pumped. I later figured out that if while at idle, if I pumped the throttle a few times real fast it would work. While at full open it seemed to run fine.

Could this be a fuel pump??

Thanks,

Dylan
 
Don S

Don S

Honorary Moderator Emeritus
Joined
Aug 31, 2004
Messages
62,321
Re: Mercruiser 140

Sounds more like the accelerator pump in the carb. Carb rebuild time.
 
J

jikol

Cadet
Joined
Sep 24, 2012
Messages
7
Re: Mercruiser 140

Do i need a rebuild kit or just take apart and clean??

Thanks,

Dylan
 
K

KX6D

Seaman
Joined
Aug 23, 2010
Messages
63
Re: Mercruiser 140

Since you have it apart, you might as well do everything!

Dino - KX6D
 
J

jikol

Cadet
Joined
Sep 24, 2012
Messages
7
Re: Mercruiser 140

Thanks guys!

I got my kit in and rebuilt my carb! It sounds and works a lot better!!! When I got the to the acceleration pump, the rubber gasket on the end was completely detached and just sitting in the bottom. I think I was only able to remove one gasket cleanly, the rest were shot. Overall condition was pretty dirty, but everything seemed to go real smooth, especially for my first rebuild!

One question I have is with the idle mixture screws. Everything that I have read about adjustments say to back it out 2-3 turns as a starting point. To get it idling smooth I had to screw them all the way in. Is that normal??

Thanks again guys!

Dylan
 
Oshkosh1

Oshkosh1

Ensign
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Jun 8, 2009
Messages
968
Re: Mercruiser 140

I'd make sure the timing is correct, then set the idle around 100RPM higher than spec(assuming it's on muffs...to compensate for the loss of exhaust back pressure). Also, to get a "snapshot" of the mixture, check your plugs. Pull one after you've got it set and look for signs of either a lean or rich condition. Use a vacuum gauge to set the mixture if you've got it.
 
Don S

Don S

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Aug 31, 2004
Messages
62,321
Re: Mercruiser 140

If it runs with both screws all the way in, then you have to much fuel getting into the engine from somewhere other than the mixture screws. Something is leaking, or damaged in the carb.
 
F

fishrdan

Admiral
Joined
Jan 25, 2008
Messages
6,989
Re: Mercruiser 140

What is the engine RPM at idle? I agree with DonS, the idle mixture screws shouldn't be screwed all the way in. On my carb they are about 1 1/2 turns out for good idle. If you have to screw them in completely, there's a leak somewhere in the carb...

How did you clean the carb?

Just a heads-up, you will need to retune the carb once the boat is:
1- in the water
2- engine completely warmed up
3- engine idling in gear
 
J

jikol

Cadet
Joined
Sep 24, 2012
Messages
7
Re: Mercruiser 140

I'm not sure my gauge works and I didn't have time last night to check. I just got it to idle smooth before I ran out of light.

I cleaned it by soaking the parts in Berrymans Chem-dip for 30 mins at a time. I did use a nylon brush to clean parts, mainly to get the old gaskets off.

Where would you suggest I look for leak? The ball bearings?

Thanks,

Dylan
 
Don S

Don S

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Aug 31, 2004
Messages
62,321
Re: Mercruiser 140

Didn't you blow the passages out with compressed air? That is one of the most important things to do in a rebuild is to make sure the passages are clear. Did you take the little ball, spring, and T installed under the venture cluster out and get it back in correctly?
 
J

jikol

Cadet
Joined
Sep 24, 2012
Messages
7
Re: Mercruiser 140

Don S said:
Didn't you blow the passages out with compressed air? That is one of the most important things to do in a rebuild is to make sure the passages are clear. Did you take the little ball, spring, and T installed under the venture cluster out and get it back in correctly?
Click to expand...

Yes. I did all of that and I think that I got the T in correct.

Thanks,

Dylan
 
J

jikol

Cadet
Joined
Sep 24, 2012
Messages
7
Re: Mercruiser 140

Would a improperly adjusted float cause this? Any suggestion on how I should proceed?

Thanks again all!

Dylan
 
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