hello all.

i have a question about a holley 4160 i have on my boat.

here goes. it's a 600 cfm 4160 and i had it reworked/modified by a holley specialist in litchfield ohio. we did all kinds of cool stuff like milling off the choke horn and blueprinting it/specifically setting it up for a marine application.

the boat seemed to be down on power lately as if it was starving for fuel so i started at the tank and worked my way to the carb thinking i had possible obstruction in the system.

when i got the carb on the bench and removed the front float bowl i found that the metering block was literally corroding apart. cracks all over it and a grimy/gritty type gunk (not a lot of gunk but there none the less).



i'm thinking it's this crap pump fuel with the ethanol in it that is corroding it.

has anyone else had anything like this occur?

the carb guy i use builds high dollar pro stock and off shore marine holley stuff so i have all the faith in the world in what he did for me. i'm sure the corrosion happened after he worked on it and has nothing to do with his work. i intend to phone him in the morning but i thought i'd see if anyone here has had similar problems.

i just want to figure this out so i can put it to bed once and for all. i may have to start my season out every year with a 55 gallon drum of known quality gasoline.

thoughts anyone?

i would suggest taking a look a little closer than the entire country's fuel supply. scum in your tank, scum in your container, or even a faulty carb gasket melt down (the black gunk)is more likely the source.

the gaskets are fine. i pulled the tank and it is absent of debris.

i was doing a google search last night and i'm fairly certain it's the ethanol blend that's the culprit. we have it in ohio. seems i'm not the only one that has had this problem with an engine that sits between usage.

anyone else?

When he modified your carb, he possibly ground away all the hard anodizing that protect the aluminum and yes the ethanol in the gas eats the carb. The carb parts should have been re hard anodized after the carb work. Ethanol around water is the worst as you found out.
Find somewhere that sells straight gas and buy your gas there.

I think it's the carbs guys fault, he should know better.

If its white like substance its moisture, if its bad enough you'll play hell cleaning it up, if its flaking chunks then like mentioned the protected surface is gone, either way your best bet is finding another MB & be done, check the rest of the carb closely for the same issues, you may just need to get another carb. Holley did have an issue with the plating coming off & the carb started chunking apart literally, i had this happen last year on a used 650dp that i purchased off e-bay believe it or not, Holley was very good to me & replaced the parts i sent them for a brand new one in the box.

Holley metering blocks are zinc die castings so they do not have hard anodizing. That would be true, however, for an aluminum metering block.
If the metering block is actually corroding get a new billet one.

Sometimes I wonder what makes me so special because I have lived in a mandatory oxygenated fuel area for 20 years and have not had ONE alcohol-related problem...at least since I stopped drinking! But, seriously, it's really easy to blame something you don't understand when something's gone wrong.

That doesn't make your problem any less real, I know.

R.

Hagertys insurance is doing a long term study of the effects of alcohol fuel on old cars and the preliminary results show no harm is caused.

I bet you got some water in the fuel.

I add the marine{blue/green} Stabil in every tank full I put in the boat...It"s just not worth going through something like you've got there...Make sure all the annodes are clean and working around the boat also...

I've been told by a local small engine specialist to use Seafoam(1 oz per gal)in anything that sits a lot, like snowblowers, to avoid carb issues

Just for some info. I bought a used Holley Street Avenger 770cfm and had problems with it. So the decision was made to go inside and take a look as to what was going on. What I found was not pretty at all. The inside of the rear bowl assembly (the casting) was literaly falling apart. A quick call to Holley only to find out my carb was on a recall for none other that bad castings. So I sent them my old carb and they sent me a new carb.