Triumphrat

vol245 · 02-10-2006

I'm thinking of getting the British Customs air box kit. I currently have Staintune pipes and 125/42 jets. I live in the Phoenix area which is about 1100' above sea level.

What should I order for jets?

You guys rool.

RedBird · 02-10-2006

Check with BC--they may supply main jets with the airbox kit. Brent supplies 150 mains with his kit for the 790's, and that is a good place to start. The 42 pilots are probably what you want also. As far as needles go, you should check to see how it runs in the mid-range area. If you have no flat spots and acceleration is good throughout the mid-range, I would not shim or change needles. If you have some flat spots in the mid-range, try one 0.5mm shim on each needle and another shim on each needle if one doesn't get rid of the flat spot. If you have to shim, you may want to order a couple of Thruxton needles (for an '04) from your Triumph dealer and try them.

The best way to get the jetting and needles just right is to get a dyno run with exhaust gas analysis, but you can get it pretty close with the butt dyno. :-D

Larry

DickBender · 02-11-2006

Vol245,
I have nearly that setup and run Thruxton needles with 150 mains and 42 pilots.
The 150s are a little rich up top and the needles are a bit rich down low.
I got 8 more hp with NARK + Mufflers, than just mufflers and UNI filter. It is a very worthwhile exercise.

I am not sure if the 04 T100 is a 790 or an 865?

If 790 get some Thunderbird Sport Needles with 3 or 4 shims (maybe more), 42 pilots and 145 mains will be pretty ***** close.
If 865 it will already have Thruxton Needles and I would go for 150s or 155s.
As Larry said the best way is to get it onto a dyno to fine tune.

Darcy

vol245 · 02-11-2006

Thanks for the info. The '04 T100 is a 790. I'm too much of a cheapa$$ to pay for dyno time. The $300 for the airbox removal kit is killing me. Good thing I just got a $4000 bonus.

BornAgain · 02-11-2006

I just ordered a BC battery box and they recomended 140's with 42 pilots and Thurx needles couple shims on the needles. I already have the Thurx needles and 42 pilots. Norman Hyde Togas exhaust. I told them to throw in some 145's. I plan on having this dynoed when I'm done. Kit should be here next week so maybe I can get it on the dyno week after and get the results posted here.

RedBird · 02-11-2006

Guys,

All carbs are not the same! Before you change needles, I highly recommend you check to see how it runs in the mid-range. EGA showed my bonnie to be a little rich in the mid-range 4K--6K rpm with the stock needles and NO shims. What works for someone with a similar setup may not work for your setup. That's why some of us recommend so highly that you get it on a dyno with EGA before too long. My bonnie with NH Togas & NARK is spot on with 158 main jets and a little rich in the mid-range with the stock needles as I said before. The order in which the pros work on the carbs is 1) get the main jets correctly sized; 2) get the needles correct for your mid-range; and 3) set your pilot jets for proper mixture at idle.

If your mid-range is too lean, you should feel some flat spots when accelerating from different speeds in your mid-range. If you don't feel any flat spots, you may be pretty close to the 13 A/F ratio in your mid-range. Installing TBS or Thrux needles could move the A/F ratio in your mid-range to 10 or 11--not what you want!

Larry