Stuck throttle valves in carburetor for Mercarb

[uhduh]

First off, great forum and very informational. I've been reading for months now and this is actually my first post.

Well, I was just ready to take the boat out first time this year, and discovered that the throttle will not budge. And after more examination found that the reason behind that was because the throttle valves inside the carburetor will not move at all. I'm assuming something got stuck or perhaps rusted inside while it was winterized. Its a Mercarb 2BBL for a 1997 4.3LX Gen with thunderbolt V ignition. I took out and disassembled the carburetor and cleaned it in hopes to loosen up the valves but that didn't work. Is there some way it can be fixed or some method to clean the throttle body without buying a new carburetor? I read soaking in motor oil might work but I'm not sure if it'll damage the carb.

Thanks for reading and any help possible.

 

[Maclin]

Re: Stuck throttle valves in carburetor for Mercarb

Sounds like the carb is damaged anyway to me! I do not have much of anything special to try to free them except using PB blaster or other type of penetrating oil. You can always wash out the oil with carb cleaner later. Sometimes the butterfly plates can get jammed into the throttle body with too much closing force, although the linkage usually bends before they can get stuck that way.

This is an odd problem, usually the butterfly bushings get looser and looser until they leak fuel out thru them. If it is siezed and rusted that bad then I cannot even imagine what other damage there is inside the rest of the engine.

Did it start and run like that? Or did you just try to move the throttle and quit before starting? Did you look at the oil? Pull the spark plugs and look at them as well, and check for moisture there.

 

[Limited-Time]

Re: Stuck throttle valves in carburetor for Mercarb

Try some penetrating oil (like PB Blaster) on the throttle shaft. Soak it, tap on it and soak it some more.

 

[uhduh]

Re: Stuck throttle valves in carburetor for Mercarb

ya I thought it was weird for it to get stuck like that. And it doesn't seem very common. The engine starts and everything runs fine. Just cannot rev up the engine since the throttle cannot move because the throttle valve is stuck. There actually isn't any rust around the valves nor inside the engine. The butterfly valves were dirty though and had signs of wear. But no obvious signs of why its stuck. I'll try some PB blaster on it, if that doesn't work, I guess a new carb it is. Any suggestions where to buy a new carb? Either online or locally in Los Angeles?

Thanks for the help

 

[Coors]

Re: Stuck throttle valves in carburetor for Mercarb

If you can break loose, or dremel the swedged screws loose ,holding the plates to the throttle shaft, you can pull the shaft, and replace the bushings.
I'd just get a new one.

 

[Don S]

Re: Stuck throttle valves in carburetor for Mercarb

If a carb is that corroded, we call them junk. There are other things that get corroded to, that you just can't fix.
Then you need to find out WHY it got like that and prevent it on your next carb.