Mercruiser 3.0L Carb confusion

[JerseyBoater]

Hi all,

My engine, 3.0L 181 Mercruiser TKS Carb (0W601238) started to die on me in idle a few ago, to the point that I was convinced that the idle assembly of the carb was blocked. The most repeatable problem I had was: start engine from cold, starts fine, runs fin, until the engine warms up. Bang on the choke doing it's thing, the engine revs would drop and then stall out. At this point there was still plenty of fuel within the carb bowl so I ruled out a fuel delivery problem. Keeping the engine revs about 1800 the engine was fine, and even got me all the way back to dock.

I dissembled my carb, and found a few flakes of a white waxy substance, one of which was right in the idle jet, so looking good so far!

I ordered a replacement gasket + extras kit and started to rebuild it, however, I think I've ordered the wrong kit. Everything supplied replaced part for part, except for the main gasket between the top half and bottom half. I either have a blocked float, or it missing out a section by the choke. The picture below shows the best choice of gasket, except this is the one that blocks the float. Can I cut the section to allow the float to rise? And what type (year?) of carb do I actually have? It is a 2bbl mercarb but there are different varieties.

The part number on the carb is:
Top line: 866140001
Second line: 33-5720

The final photo shows the gasket that I think I should have, having been replaced by the one that doesn't seem like it will work with my float!

Thanks

 

[alldodge]

Hi all,

My engine, 3.0L 181 Mercruiser TKS Carb (0W601238) started to die on me in idle a few ago, to the point that I was convinced that the idle assembly of the carb was blocked. The most repeatable problem I had was: start engine from cold, starts fine, runs fin, until the engine warms up. Bang on the choke doing it's thing, the engine revs would drop and then stall out. At this point there was still plenty of fuel within the carb bowl so I ruled out a fuel delivery problem. Keeping the engine revs about 1800 the engine was fine, and even got me all the way back to dock.

I dissembled my carb, and found a few flakes of a white waxy substance, one of which was right in the idle jet, so looking good so far!

I ordered a replacement gasket + extras kit and started to rebuild it, however, I think I've ordered the wrong kit. Everything supplied replaced part for part, except for the main gasket between the top half and bottom half. I either have a blocked float, or it missing out a section by the choke. The picture below shows the best choice of gasket, except this is the one that blocks the float. Can I cut the section to allow the float to rise? And what type (year?) of carb do I actually have? It is a 2bbl mercarb but there are different varieties.

The part number on the carb is:
Top line: 866140001
Second line: 33-5720

The final photo shows the gasket that I think I should have, having been replaced by the one that doesn't seem like it will work with my float!

Thanks

Appears you have the correct gasket see item 31
http://www.mercruiserparts.com/Show...11540.png&inbr=11669&bnbr=70&bdesc=Carburetor

The gasket will go on the top plate of the carb, then install the float, then put the two halves together. I've seen this design many times, not as easy as one you just lay on but it works. Do all your float adjustments prior to installing the gasket

 

[JerseyBoater]

Hi AllDodge,

Yes that's the gasket I think I should have, but my one only has small L shape cut out, whereas that one go all the way to the center hole.

Thanks,
Michael

 

[alldodge]

Sorry I'm having a bit of trouble understanding, haven't had enough coffee yet I guess

Yes that's the gasket I think I should have, but my one only has small L shape cut out

If you saying that the gasket in the second pick is the one you should have but do not. If this is the case then you have the one with the L shape cut out?

, whereas that one go all the way to the center hole.

What goes all the way through the center?

 

[thumpar]

What does the one you pulled out look like?

 

[JerseyBoater]

No Title

Right problem solved, it wasn't actually an issue as such.

The gasket I pulled out, looks like the top one in this photo, and the one I got, was the bottom one. Originally I feared that this blocked the float from rising all the way to the top, but it seems ok in reality (I put the carb back on the engine yesterday and got it started and running).

What it does block though, is the tube from under the flame arrestor, that goes to the fuel bowl that you could use to fill the carb manually.

Strange, but there you go! It works!