Carburetors: A Cautionary Tale

So, i just recently finished painting my 74 comet, and thinking I was done with body work for a while. Turns out I was wrong. I have a Holley 600cfm 1850-2 model, and my car was running kinda rough so i had been doing some tuning on it trying to get the floats set right and the idle correct. I pulled into my driveway after taking the car out for a spin and popped the hood to check something (the car was running in park) I had the hood open a few seconds and poof, the whole engine bay was on fire and flames were shooting out both sides of the car. Did the only thing i could think to do at the time. Shut off my fuel pump and ran and got the hose and sprayed the engine down until the flames died. I have my fuel pump seperate from my ignition so the car continued to run until it hydrolocked. The engine wasnt my priority at the time. It was more keeping the whole car from burning to the ground. I found my culprit. A small paper gasket that goes between the holley float adjustment screw and bolt had torn and was leaking fuel onto the intake manifold. So needless to say when i adjust the floats from now on there will be a new gasket every time, along with a fire extingusher. Ended up rebuliding the whole carb. Re wiring half the car... man that was fun... and working on scraping off all the melted paint and fixing the hood. Coulda been a lot worse. Pretty sure if that had happened while i was driving the car would have burnt to the ground.

Hood pic #1 (http://i.imgur.com/W3nThG6.jpg)
Hood pic #2 (http://i.imgur.com/bhRJexV.jpg)

 

Sorry to hear of your misfortune. Hopefully you can bounce back with little trouble. And I agree, it could have been A LOT worse! Glad everyone is safe!!

 

Yep its running. Took it out today. Looks like I escaped pretty lucky. Everything is back to normal except the hood. Sanding that and primering it right now...

 

I've always hated those stupid little gaskets. There's gotta be a netter way.

 

Yeah, like a hard metal gasket coated in rubber or something more durable...

 

What about the copper rings for attaching the brake hose to a caliper? I've used them for the seal on small spark plugs.

 

Id have to figure out what youre talking about. Most metal rings dont seal because they dont compress enough to keep gas from leaking out...

 

If you try to overtighten the lock screw it will tear the gasket. It doesn't take a ton of force to hold it all together. Be sure to adjust with the nut then tighten the screw. Don't turn the nut against the screw to get it tighter.

By the way, an 1850 Holley is a 600cfm Vacuum secondary carb, not a 650.

SPark

 

My bad on the cfm. I had a 650 eddlebrock before this.And that is how i adjust the floats. The paper gaskets are still very flimsy...

 

Yeah, you have to be careful when snugging them down. In any case, they are not very durable for multiple adjustments to the floats, so get it right the first or second time.

 

Exactly my point. Im just gonna make it a personal habit to put a new one on when i make an adjustment. If or until i can find a more suitable replacement.

 

These are thin copper seals that are used for attaching the brake hose to a caliper. One goes on each side of the hose end (steel block) that the bolt goes through to tighten it to the caliper. You can get these copper seals at any auto parts store. Copper is soft enough to make a good seal! Now, the question is, will they fit? That I don't know, but you can take your old gasket and compare the size.

 

They make nylon gaskets for the needle and seat adjustment screws. I think there's enough in a package to do 2 carbs. There are a couple of companies that sell them and it's around $8 if I remember correctly. They work great and you can use them over and over.

 

I've always used paper. Never used the nylon ones, I've never even seen a set of them. Never had a need to look for them.

When we raced I adjusted floats to different track conditions. I never changed the paper gaskets. I've run the same gasket all year without a single problem. Only changed them when we freshened carbs during the winter. Our carbs were apart a lot with jet changes and I always adjusted floats afterwards, never a leak.

The thing to look for is a small burr on the bottom of the screw or top of the nut OR small pieces of the old paper gasket stuck to either surface. Make sure the rectangular hole on the nut doesn't have a ridge around where they punched the hole. I always file the top of the nut flat and polish with a scotchbrite pad.

Look for the burrs, polish the mating surfaces and adjust correctly and you should never have a problem. There is absolutely no reason to change gaskets all the time.

SPark

 

There's always gonna be somebody who's "never had a problem", but it only takes once to start a fire and destroy your car.

I love it when guys say they've run air-shocks on their Maverick for years and "never had a problem". Well, the people who had their upper shock mounts completely ripped out of the body aren't very pleased about it.

As much as these carbs cost, they should be fool-proof.