Mercarb PIA

[sal3030]

I have rebuilt my mercarb (4.3L) When I set the float to 14mm it floods. I raised it to 17mm, doesn't flood, but stalls when I goose the throttle. Set it back to 14mm and changed to a springless solid needle. It floods. Nothing wrong witn accelerator pump, change that twice. Two new floats one sierrra the other quicksilver. I have no more Ideas. Full tank of new gas new fuel filters good fuel pump. I have no more ideas if I pop it up to 3000 Rpm it is fine, any more vacuum goes to 0 and it boggs and stalls. Can I change out this Carb? What will fit?

 

[sal3030]

Re: Mercarb PIA

I should be more clear. Sorry. Would it be a better idea to get a Rochester 2gc and scrap the Mercarb? I see that there a lot of problems with it. Thanks

 

[90stingray]

Re: Mercarb PIA

I went to the spring loaded needle myself. Not sure what the float height and drop numbers are but they are different from solid to spring styles. I would triple check all my measurements. Mercarbs do have a off idle issue. Mine is only there when I am pulling a skier. I wouldn't give up on the mercarb just yet. But if you got the cash to blow go for an edelbrock 4bbl intake and carb... and never look back.

 

[sal3030]

Re: Mercarb PIA

No. I don't have the cash and will stick with it. It will be getting cold in a month or so anyway. I messed around and put the spring needle in again set the drop at 27mm and the level at 17mm. It is a lift of about 1/8". Still the same problem. I actually lifted the trailer up to my shoulders to tilt the engine back and it doesn't stall. I will live with it for now. I don't pull anything that need rapid out of the hole speed.

 

[sal3030]

Re: Mercarb PIA

What did you mean by "off idle issue" "when pulling a skier" ?

 

[90stingray]

Re: Mercarb PIA

Yeah, when you mash the gas w/o a skier boat will throttle up just fine. Put a skier back there and it will studder just a little then take off. I have messed with timing etc... still does it. But if I roll into the gas sure wont do it. Goodluck!

 

[sal3030]

Re: Mercarb PIA

Thanks Stingray. As I said, I will wait until next year. Hunting season opens in two weeks, no more time for boating.

 

[cliffblue]

Re: Mercarb PIA

I just went through my 2001 mercarb. I had an idle jet stopping up, but it ran great above idle. When I checked the float level, it was sitting higher (with the carb top inverted) than the spec. in the Seloc manual. It ran great before the blockage, so I left it alone. It runs great now with no hesitation pulling a tuber. Could you have gotten the accel pump rod in the wrong hole?

 

[Volphin]

Re: Mercarb PIA

Thanks Stingray. As I said, I will wait until next year. Hunting season opens in two weeks, no more time for boating.

Duck hunting anyone? Best of both worlds!
I think you have a clog, not a float issue.

V

 

[sal3030]

Re: Mercarb PIA

Mine is a 1988 by the way. So from what you are saying your float is is more than 14mm when inverted? I think this is the way the boat lays in the water that Merc can't account for in every case. Oh, I only have one hole for the pump arm.