4 replies to this topic

[Chippy749]

Hi everyone.

 

Im towards the end of rebuilding a 1293 cc pre A plus engine with an original 649 camshaft originally put together by speedwell i believe, and I'm looking to see if any of you good people could offer any advice or experience on what sort of jetting and venturi choke sizes i should be looking at for the weber 28/36 DCD carburettor which is currently running my cammed 998 with the following jet sizes 

•   main jet 130
• secondary main 140
• primary choke barrel 24
• secondary choke barrel 26 
• both idle jets at 50
• and a 70 pump jet

Runs really well but no doubt it will all be to small for the 1293.

any help or suggestions would be greatly appreciated 

[whistler]

Hi everyone.

 

Im towards the end of rebuilding a 1293 cc pre A plus engine with an original 649 camshaft originally put together by speedwell i believe, and I'm looking to see if any of you good people could offer any advice or experience on what sort of jetting and venturi choke sizes i should be looking at for the weber 28/36 DCD carburettor which is currently running my cammed 998 with the following jet sizes 

•   main jet 130
• secondary main 140
• primary choke barrel 24
• secondary choke barrel 26 
• both idle jets at 50
• and a 70 pump jet

Runs really well but no doubt it will all be to small for the 1293.

any help or suggestions would be greatly appreciated 

There's some recommended setups in David Vizard's book;.

[Chippy749]

Thanks for the reply. I've had a look at it as I've got the book but he only goes as far as 1275 which I'm sure would be a very good starting point if not good enough and seems likely to be the only way to be honest. Was just hoping there was someone out there with specific experience of my setup and carburettor, I'm sure it's a long shot but worth a try ay haha

[nicklouse]

Having used one of those carbs I would not bother. You will get better results from an HIF44.

 

But as mentioned Vizard gives some starting points for before getting on the rollers for set up.

[Chippy749]

I seen that some people aren't a fan of them and that the hif44 can produce asmuch power if not more from what I've read but I am a fan of the weber so I'll see what I can do with it I think. But yeah I think vizards book seems to be the best place to start for sure