carb rebuild

[tropyal]

Hi
This forum has helped me before with great success. But now I have a different problem. My 77 searay with 302 Ford Mercruiser was not accelerating well, but it would idle just fine. I rebuilt the carb with a NAPA kit and can not get it to run properly. Once running it seems to be dumping fuel into the carb. I took it apart again and changed back to the old power valve (yes it was different) and still does the same thing. Idle screws make no differance. My vacuum gauge reads almost nothing, but I cant figure out why, or where the leak is. Any suggestions would be greatly appreciated. At this point I am leaning to real Holley rebuild kits and not the aftermarket.

Thank You in advance
Doug

 

[TiredoleBoy]

Re: carb rebuild

Take it apart and blow out all the idle passage ways. With an air gun at high pressure. Sounds like a bit of dirt is stuck somewhere.

 

[tropyal]

Re: carb rebuild

Very possible, I cleaned it the best I could with out air, but the prior owner sealed eveything with gasket sealer and I spent a lot of time with a wire brush and scotch brite cleaning the surfaces, but a piece may have got into a place it should no be. I will try again in the morning> Thank you

 

[TiredoleBoy]

Re: carb rebuild

get some gum out and spray in the passages to loosen and then blow it out with a high pressure blow gun. I have rebuilt 100's of carbs in the past and usually this is what the problem is. That tack sealer is a bear to get out of small passage ways. I also like to use a small section of wire just a tad smaller than the passage way when in doubt.

 

[Bondo]

Re: carb rebuild

and I spent a lot of time with a wire brush and scotch brite cleaning the surfaces,

Ayuh,.... It's more about the Passages that ToB talks about that Count,...
Not so much the surfaces...
Ya also gotta understand that some carbs can't be saved by a backyard rebuild either,....

 

[TiredoleBoy]

Re: carb rebuild

.
Ya also gotta understand that some carbs can't be saved by a backyard rebuild either,....

Yep been there.

 

[tropyal]

Re: carb rebuild

Alls good. I cleaned and blew out all parts put it back together and still did the same thing. I had kept all the old parts and started matching everything up. The gasket between the main body and middle block was different. Put the old gasket in and ran like a charm. The correct gasket was suppose to be in the kit, but was missing. New kit on its way hopefully with the correct gasket.
Thank You for your help
Doug

 

[fat fanny]

Re: carb rebuild

I guess it just goes to show you how much comparing the old parts with the new replacements pays off before even starting the rebuild process.

 

[TiredoleBoy]

Re: carb rebuild

I guess it just goes to show you how much comparing the old parts with the new replacements pays off before even starting the rebuild process.

You kidding me? If the parts don't match they don't get used. Yes gaskets for different applications are used in these kits. If they don't match........ After 30 years of rebuilding it is common to compare prior to a rebuild.

 

[tropyal]

Re: carb rebuild

well I don't do this for a living give me a break. I can give you information on pre 1915 cars and how to make almost any part, that is what my experience is. This forum seems to be more about arguing with each other and knocking people down than simply helping of fellow boaters. Just read a lot of the other posts.

 

[cr2k]

Re: carb rebuild

When you finally get the right new gasket, compare your accelerator pump spring, the one on the plunger it self to your old one. If your old one is stiffer take it apart and use that one. A lot of the NAPA, Sierra Supply kits come as repackaged automotive kits (and as we know cars are smogged) and use a weaker spring. Not good. And yes most of the kits today are multi fit kits so comparing gaskets is a must as well as hoping the last guy used the correct parts.

 

[tropyal]

Re: carb rebuild

Thank you, I have re ordered a complete marine kit via a local boatyard