Floyd Brothers 70 Challenger

[Stu]

Completely confused now…

Whipped the carb off, swapped the jets, came to drop the baseplate gasket on and it doesn’t line up.

If I line up the bolt holes, the others aren’t in line…

Kit is supposed to be correct, so what am I missing? Or is it the wrong gasket!?

[Stu]

Actually, think this might be a case of thickus-twattus.

Re looked at the pic of the table and the gasket I’m looking at looks like the one that goes between the main body and the baseplate. If that’s the case, then I think it only ever had the rubberised open square gasket between the baseplate and manifold.

Does that seem right?

[mygasser]

not sure what the problem is mate, the second pic shows the gasket in its correct orientation so you're good to go. if you meant the three small holes then they're of no concern, some gaskets have them and some don't? either way you have no issues.
neil.

[Stu]

Holes down the centre of the base plate don’t line up with the gasket holes.

[Blue]

As long as the butterfly’s and the mounting holes line up don’t worry about the other holes, they are not normally there and I can’t see their purpose. I always avoid thick manifold gaskets, it’s a sure way to bend the carb baseplate. Remove the gasket, drop the carb on the studs and make sure it doesn’t rock and try to get a very thin feeler gauge between carb and manifold all the way around, if it goes under you have bendage, If not use that nice thin gasket you have there and call it done.

[Stu]

Cheers Blue. It’s back on now with just the thin big open square gasket, as I needed to get on. Does it need the four hole gasket as well?

Currently trying to figure out the electrical gremlins.

[Stu]

Er… not a great start to my foray into carb tuning… engine kept dying whilst trying to check the electrics, so was just adjusting the idle. Put it up to 1k and was better, dropped it down a touch and it stumbled, realised I’d dropped it too low and was just tweaking it up, when it stumbled, popped and poured out a load of smoke… turned it off a bit sharpish, but now unsure whether all is well and it was just me or not.

[Stu]

Very disheartening afternoon. Giving it neck for now.

Fuel leaking and whole thing running like a bag of Bananarama!.

Won’t stay running, even when I set the idle up to 1k it goes for a few minutes, then stumbles and dies and belches smoke out the carb.

Still clueless on the electrical problem, looks like my carb rebuild victory has turned into a fail and another sunny day I can’t drive it.

Going for a beer.

[Stu]

Just so I am clear what I am talking about, when I took this off, it just had a rubberised version of the gasket in photo 1, below.

When I replaced it, I used the fibre / paper type gasket the same shape.

I then found in the kit the gasket shown in pic 2. This fits the manifold, but in that orientation puts the three centre holes 90 degrees out to the ones in the baseplate.

My two questions are :

1. Does the three holes in the base plate being blocked matter?
2. Do I need both gaskets? If not, which one should I use?

Ta.

[Stu]

FFS, just discovered it looks like I’ve got a crack in my rad to cheer me up.

[mygasser]

the three little centre holes in the gasket do nothing mate, ignore them.
in fact now i see you have a single plane inlet i'd cut the centre out like the old gasket. if not it'll slowly sag, tear and break off, dropping bits into the engine, not good.
neil.

[Stu]

So essentially, it was right in the first place and I didn’t need to take it off again…

Oh well, I’ll take it off again in the week and get rid of that top gasket.

Cheers for the help.

[mygasser]

pretty much, lol.

[Stu]

Thanks to the legend that is Scotty Dave, had a spare regulator to test with today, so cleaned everything up, made sure had good earth and Bob’s your mothers brother, looks like it has stopped the overcharging!

Mancini kit should be here in the week by the looks of it, so will do the conversion asap and have done with it, but relieved to see it’s seems ok for now.

Had the carb off again and got rid of the 4 hole gasket, got everything running just now, so about to adjust float levels and fingers crossed… may go for a spin!

[Pete]

Excellent - small steps to progress!