Main Jet size

fb cruisin · Post by **fb cruisin** » Wed Jun 17, 2009 9:48 pm

Hi guys,
I've been searching for a while to try and find out what main jet size I should run with twin carbs, on my grey motor?

I have pulled the jets out of 3 twin carb set ups recently,
and 2 were using 51 jets, which are original.
1 set up was using a 47 main jet

So I was keen to find out what most guys on this forum use in their own twin/ tripple carbs.
Cheers Rob

oldnek · Post by **oldnek** » Wed Jun 17, 2009 10:43 pm

Give 43's or 44's a go Rob, and shift your Accel pump link to the longest stroke setting hole ( last one on the link), if it idles bad and your running a lumpy cam you can drill the throttle plate slightly. If you stuff it up you can easily resolder it.

I had a EH running 149 with twins and the mains were 49's, went pretty good
They would of suited a 161 engine better, I think.
A tip here:
The way I tune carby jets is to get some need-it fill the jet, and with some jet drills just cut what hole size you need. Once it's pretty close then you buy the correct jets to suit, its a lot cheaper and you get much faster results than by soldering and drilling. And if you stuff up only takes 5 mins and your back in action.

John

fb cruisin · Post by **fb cruisin** » Thu Jun 18, 2009 10:03 am

Thanks John I'll give that a try.

Cheers Rob