Amal cover gasket leak

[BSA500]

Hi put a new monobloc cover gasket on which now of course leaks like a sieve. What do you do to soften up new gaskets as its like piggin rock. I have this problem all the time with new gaskets for amals the fibre washers are horrible. i have an old leather type seal I have used for years on the bottom main jet holders never ever leaks the fibre washers always do.

[BSA500]

I have decicded it would be easier just to make my own my own I have plenty of gasket paper and a nice sharp blade.

[RDfella]

Soak then in water - but be aware they get larger and holes my not line up. Often used on old stock gaskets which have shrunk.

[BSA500]

Yeah thats the worry with soaking, I shall just use it as a template and make one out of the gasket paper I have which is the same thickness but softer

[Rex]

Never tried it with the Amal cover, but the trick with the new rock-hard fibre washers is to soak them in oil overnight.
Probably why Amals which have been treated to new washers leak like a sieve on the first day, then magically don't on the second.

[groily]

Over the years I've had to reface the float chamber lids of several Monoblocs because people overtighten the screws. Sometimes the fix for a leak  is 'just a gasket' or 'rock-hard fibre washer' thing, but when the mating surfaces don't, it can be like pushing unset jelly up the sunny side of a pyramid trying to cure the problem.

[BSA500]

I  refaced my float bowl cover a while back  for that reason. I just don't see why they produce gaskets like this they are next to useless..

[trevinoz]

I would use a file on the cover to flatten the high spots, Groily is correct ion his views.
I have had the same problem and a few minutes filing cured it.

[BSA500]

Cured with my new gasket and wellseal

[CheeserBeezer]

Cured with my new gasket and wellseal

Pleased to hear it. The problem (obviously - grandmother sucking eggs etc.) is that, fundamentally, the cover is too thin so it warps where the screws go in. There is insufficient mating surface where the screw holes are, so a slightly warped cover will cause leakage. A good cure is to dispense with the Amal cover and use one of the period float bowl extensions which were available. These can also be skimmed down on a lathe so they're not as deep and less obtrusive. There were various types available and some have quite a bit of 'spare' aluminium on the outer face so, if you want to be really clever, with a bit of extra time on the lathe, you can fit the original Amal cover over the top of it.

[BSA500]

In this case wellseal is my friend 

[BSA500]

that went well one day back with the correct carb and she looks like the idle jet is clogged again. I stopped for ten minutes and when I went to restart she wouldn't. took god knows how many kicks but start but she did and got her home. Refused to start again. swopped back to the spare again and difficult to start and will not idle. Suggests the idle circuit/jet is not flowing right.

[muskrat]

G'day 500.
I would shy away from using any sealant on a carb gasket. Two reasons, 1 fuel will eventually eat it and 2 any excess that squeezes out of the joint will block jets.
Best to make sure both mating surfaces are flat and use just a thin wipe of grease on the gasket.
Cheers

[Peter in Aus]

Rap the gasket very carefully with Teflon tape, works well for me for many years.

[BSA500]

I trust wellseal not silicon based non hardening so no lumps floating around and you can paint it on thinly with a paint brush. I would prob go with Andrews idea of an extended float bowl for a more solid gasket face. I have now put my incorrect carb on(15/16 instead of 1 inch) as it just will not run properly. Only issues with the smaller carb is the mixture screw thread is knackered and she runs rich. As an extra question found the jet block in the 1 inch carb is marked 1.062 instead of 1.00 run with it for years what issues if any could that cause??