Manifold, carb, exhaust pre instillation prep to help ensure no leaks

[Wevil Kenevil]

Carb: Sand the top of the float bowl flat so it gets good seal and eliminates most air and fuel leaks . This is where most mystery air and fuel occur.

Manifold: You can get more volume of air if you grind out the inside of the manifold.

They are quite thick and are forgiving.
Lower the bottom or the throat especially. (Looking in the carb end and down to where it goes into the cylinder. )

Sand the area that mates smooth and Flat.

Match it to the intake port hole for optimal flow.

Exhaust pipe: make sure flanges are flat and welds won't interfere with the fasteners and washers sitting flat against the flange.

File down the inside pipe edge to match the opening on the exhaust port.

If you find that your exhaust pipe doesn't quite get a good seal (ld100 cylinder) build up the outside of the exhaust port with metal putty. Just make sure you pack it down into the fins against the outside cylinder wall.

I use red and black gasket sealer lightly smeared on just to give the gasket some volume.

These are just a few aspects that I don't hear talked about much.

 

[wrench]

In my experience the float bowl will usually warp if the 2 little screws that bolt the float bowl to the carb are over tightened
Then the float bowl will have to be resurfaced

Same with the carb mounting flange to the intake
If the bolts are over tightened the carb mounting flange will warp
Then the flange has to be resurfaced

 

[Wevil Kenevil]

Yes I noticed there is a very slight gap between where the float bowl bolt and the body of the carb meet..

This is especially apparent on the "HP" carb because it doesn't have the lip and gasket around the outside of the perimeter, it has the half round "o" ring gasket in the middle of the lip of the float bowl so you can actually see the mountng surface and how it fits.

Over tightening the float bowl wouldn't be an issue with a resurfaced f bowl. But anything in the primo zone will stop ANY leak.