worth trying a different carb?

[Stanglover]

A final thought. I was thinking about spacers and decided to check my Carb bits box. I have a 1/4" insulator gasket that I purchased at the local rod-rod store. This one is not a spread bore, but I would have to think they make one. If you can find one of these, then hopefully, problem solved. If you do not plug the heat riser passages, there is a bottom basket with a metal insert (between the top and bottom paper layers) that you would also need. You would need this gasket if you decide to go back to the 4300D. I can't help with numbers as like I said, my stuff is not spread bore. My thought on blocking the risers is it creates a dead air space, a good insulator, whereas high temp putty would still transfer some heat. That's my theory and I'm sticking with it!!!!

Let us all know how it works out for you.

Geoff.

 

[barnett468]

Cranking just fine when warm. Not more slowly. Soubds strong. Just won't catch without multiple attempts and various machinations with the gas pedal.

Simple.

1. Look in the front carb venturis and slowly open the throttle 1/8th and see if it shoots two streams of gas . If it does not, that is part of the prob.

2. Advance the timing 4 degrees when it is hot and see what happens.

3. If you plug the vacuum advance and advance the timing 4 degrees at idle and the rpm goes up and it still runs smoothly, it needs more idle timing.

4. If you do the same thing at around 2000 rpm and the rpm goes up and it runs smoothly it needs more timing there also.

 

[Twins]

Cranking just fine when warm. Not more slowly. Soubds strong. Just won't catch without multiple attempts and various machinations with the gas pedal.

Simple.

1. Look in the front carb venturis and slowly open the throttle 1/8th and see if it shoots two streams of gas . If it does not, that is part of the prob.

2. Advance the timing 4 degrees when it is hot and see what happens.

3. If you plug the vacuum advance and advance the timing 4 degrees at idle and the rpm goes up and it still runs smoothly, it needs more idle timing.

4. If you do the same thing at around 2000 rpm and the rpm goes up and it runs smoothly it needs more timing there also.

Got it. Thanks

A final thought. I was thinking about spacers and decided to check my Carb bits box. I have a 1/4" insulator gasket that I purchased at the local rod-rod store. This one is not a spread bore, but I would have to think they make one. If you can find one of these, then hopefully, problem solved. If you do not plug the heat riser passages, there is a bottom basket with a metal insert (between the top and bottom paper layers) that you would also need. You would need this gasket if you decide to go back to the 4300D. I can't help with numbers as like I said, my stuff is not spread bore. My thought on blocking the risers is it creates a dead air space, a good insulator, whereas high temp putty would still transfer some heat. That's my theory and I'm sticking with it!!!!

Let us all know how it works out for you.

Geoff.

Thanks Geoff. Working it all out now. One other thing. Do you know if the Id of the fuel line running from the fender apron to the pump is normally 3/8? Thanks.