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View Full Version : Better Carb set up TRX90?


Pappy
08-24-2005, 06:46 PM
After a few dyno runs, we realized that our little 90 is needing much more then the stock carb will allow.

I have a larger Keihn carb here and it is going to be a very close fit, but the larger issue is where can I find a throttle cable, or how to go about making one.

Also, if anyone knows a good set up that is easily installed I sure would appreciate the info. Not much time for trying things so I need the best options I can get.

Thanks.
Pappy
08-24-2005, 07:26 PM
I did some searching and came up with a 200x throttle cable. Any out there that can verify this?
BSTURDIVANT
08-24-2005, 08:27 PM
Xr100 carb cut down a 400 cable. Never tried atc cable, might just work! Also need to open up the intake manifold and intake port for added air delivery! only about 16mm factory!
Pappy
08-24-2005, 09:21 PM
thanks.

she is fully ported, including the intake. much more open and she probably would be too much:p it runs strong, but we know there is more power in there and we need evrything we can get!
Pappy
08-25-2005, 07:09 PM
figured it out.

going with a 24mm Keihn for now...lol
400ex4ever
08-26-2005, 06:51 AM
That's what I am going to put on my son's Predator (Monday). From all the research I have compiled on witch size does this sound about right for the Predator? I have a High comp head and plan to get it port/polished. As long as I don't go big bore I should be good???
ROBBSRACING
08-26-2005, 11:51 PM
Dont over do the carb. You will see that a big carb on a 90 displacement engine takes away a ton of bottom end and throttle response. We run 24s on the 125cc TRXs that we build. I would think that for CC racing you want as much bottom end and throttle response as you can get. Peak HP numbers on the Dyno sheet dont mean nothin in the woods ! Just trying to help through my own experience with testing.
Pappy
08-27-2005, 06:48 AM
rob, thanks for the advice here and on the phone. not long after we talked, i had a buddy offer up the use of the. we will put it back on the dyno and see what it does. if it doesnt work we will be trying the 20mm as you suggest.

and i fully agree, XC isnt about pure power etc. we are just looking for a happy medium.