I think a carb problem?? Any help certainly appreciated.

[boatFam]

I am thinking someone here will have a suggestion regarding this problem. After de-winterizing my boat this summer, took it out and it ran a bit sluggish. Engine is a 4 cyl 1993 Mercruiser 140 HP with Mercarb 2 bbl. Last summer, it ran fine. It felt like it might be the carb so I rebuilt it with the proper acc pump, etc. Put fresh plugs in, compression check okay, etc. Started it up, ran great at idle in my driveway... took it to the lake and under load it was a dog. Plus gas would leak from the venturi(s) when turned it off. Okay, today at home took carb off and oops, put the spring in the fuel filter in the wrong place. Changed that according to the Merc manual and this time measured the float, which was way off.. (explains fuel overflow.. I know, I got sloppy and forgot at the rebuild). Anywho, ran it again in the driveway and it still has a slight hesitation with giving it FOT, like when water skiing. I looked at the top of the carb and noticed the choke butterfly will not open all the way. Rechecked the linkage and it will open all the way when the linkage is not attached. However, when putting it together like the manual says (service manual #24).. the butterfly will not open. I am attaching pics of this.. The linkage goes all the way down and there is no more play in it. Oh, I made sure it isn't the electric choke stopping it.

Question: Is this normal and if not, will it cause the hesitation like I describe?

Question: Any other thoughts here what may be going on?

It is only 140 horse and I need every ounce of power to get my butt out of the water to get on the surface to ski..

Thanks in advance.

 

[boatFam]

Re: I think a carb problem?? Any help certainly appreciated.

Bump. Hoping someone can help here. Thanks.

 

[kd7isf]

Re: I think a carb problem?? Any help certainly appreciated.

Check the yellowish line that goes from the fuel pump to the carb.
Is there fuel in it?
If so, replace your fuel pump.......
This is a saftey feature -- when the pump goes bad, it floods the engine rather than the bilge....

 

[fat fanny]

Re: I think a carb problem?? Any help certainly appreciated.

Some things to remember when re-building a carb isthe success ratio is 50/50. A couple of other things to look into are fuel tank vent, fuel pick up tube and it's screen at the bottom, Any loose and or corroded electrical connections, Corrosion uneder the dizzycap or mosture along with possible stale gas from previous season, Also is your timming set correctly (is it EST) ? requires a special proceedure, I know attimes my 96 suffers some slight hessitation out of the hole but it's only momentarily and it just may something you will have to get used to or go back through your carb and make sure there is absolutly no binding what so ever in any of the linkages and especially the accelerator pump action must be smooth. Hope this helps and good luck.