[chrisvalley]

hi there
i'm installing TORs this winter on a 2003 bonnie (790cc) with AI removed, unifilter installed but snorkel still in place.
I've thruxton needles that I can install if necessary.
Any suggestions on the likely jet sizes needed with or without the thruxton needles?
I understand that TORs come with a set and it may be possible to specify which size upon order.
Thanks
Chris

 

[webonnielad]

Speak To Mike Selman at

http://www.bellacorse.com/index.html

He Knows his stuff

or Peter Jenks in the UK who has downloads for all types of set ups, he's dyno tested everything very thoroughly.

http://www.triumph-bonneville.com/

All the best

Jon (UK)

 

[Whitehurst]

People at bellecorse will not give you advice unless you buy something from them. I would not recomend these people ...

 

[Big_Rick]

Check here:

Jenks Carb Tuning Guide

Go to page 10. This will give you a good starting point.

 

[kliff]

Go to this site, and use Dinqua's jetting calculator...best thing since sliced bread.

http://www.dinqua.com/http://www.dinqua.com/

 

[Big_Rick]

Pat's calculator is pretty neat! The down side is that you can only calculate what size main jet for particular needle/pilot set up. It doesn't help you determine the best set up for your particular intake/exhaust setup.
That's why I like the Jenks guide. It gives you a good starting point for almost any setup, then you can either go with that or get it checked out on a dyno and fine tune it some more.
The other thing on the calculator is that I don't see anything to select your displacement, so I would assume that it is for 790cc engines.

 

[bgaz]

I think the dynojet kit is worthwhile as it includes 4 jets and a needle with 5 or 6 positions, along with softer slide springs.
Gives you a lot of choices for changes and experiments...

Brett

 

[RedBird]

You should wind up somewhere around 125 in the main jet area. The needle used has NO bearing on the size main jet needed. I would recommend using the stock needles first and if you detect any "flat spots" in the mid range, then try some shims or the Thrux needles. It is always best to get it on a dyno with EGA when you are through tinkering. I run a 790 with NARK, NH Togas, and the main jets are 158, the needles are stock (mid-range is a little too rich with the stock needles), 42 pilot jets (the stock 40 pilot jets would work also). I have averaged 50+ mpg over the last 15000 miles with this setup--oh, yes, I have a modified igniter with a rev limit of 8100, and I spool it up quite regularly. :-D

Larry