TRX90 questions and some help.....

[fastlx]

Ok, where do I start.... I have a 2003 TRX90 that is ridden by my 9 year old daughter. We ride mostly in the dunes, but do some trails riding. Here is what I am looking for. I would like to buy a BOLT on big bore KIT, yes KIT for it. I own a CRF50 and it has a big bore kit on it that was purchased as a complete bolt on kit. That is what I am looking for. Does anyone have such a beast? I want to get a bit more power to help turn the paddles and go up some of the bigger hills. Right now it is totally stock, and it did ok last summer when we went, but when we go back to the dunes in April, I want to have a major improvment for her. Here is the kicker, I dont want to spend a million bucks. Any help would be great. Thanks!!!

[badvox]

http://www.powroll.com/P_HONDA_TRX90.htm

[fastlx]

Not exactly what I am looking for. I dont want to have to bore the cases. I would like a new cylinder, piston, intake, carb, etc..... all in one happy kit, like I can buy for my 50. Anyone know if this will work.....

http://www.hondatrailbikes.com/catal...roducts_id=779

The cylinder is 69mm tall. Thanks for all your help.

[3-D Racing Dad]

http://www.icracing.com

Give Eric or Mike a call and see what they have...

[fastlx]

3-D, I see that you have a TRX90. What have you done to yours?

[3-D Racing Dad]

Well it's a long list... but here are a few of the high points.

ICRacing suspension:

Dual A-arms
Hydralic brakes front and rear
ICRacing swingarm
Titanium Axle
Works shocks

ICRacing motor

124cc Stroker
26mm Kehien carb

She will be a full race ready quad when it's done..

[3-D Racing Dad]

Pappy is a good one to talk to as well..

[fastlx]

Ok, I will do that, thanks! Calling Pappy, where are you?

[Pappy]

why me

ill lay it out the way it has been explained to me by builders and those that have run big bore 90's.


Once you break the threshold of some magical cc number (noone has yet to tell me exactly what that is) there seems to be a disagreement between folks. Builders and those running big bore kits have gone both ways on what im about to tell you, so in all honesty i have no idea on who is correct....


Almost every person ive chatted with that is running a stroker or a big bore 90 has complained that power goes away due to overheating. riders complain of lack of power near the end of a 45 minute XC race etc. Some builders have agreed with this while others call horse hockey to it. The builders who disagree claim that cylinder wall thickness is the same as a stock engine so how could overheating be an issue.

Now, I am abslutley no expert on engines. i know enough to usually keep our stuff together and running good, but thats about it. Add in the fact that relaying info correctly over the net is an art and im no artists

We have been running a true 90cc TRX90 for competing in the GNCC 90CC Production class . Ported head and intake, 11-1 Powroll Piston and Cam, and a 20mm carb. This engine produced 7hp at the rear wheels on a dyno, while a similairly built 90cc 2 stroke will push 11hp. We have been pretty happy with our power output, but with new rules in place this season, the 125cc is an option for us.

Plans are for now to run a 124cc stroker built to the hilt in hopes of gaining every bit of power we can. How this holds together is still up in the air, and thankfully I have a few weeks yet to investigate more options.

I probably added to your confusion, but thats all I know. I do not know of anyone producing a bolt on big bore for the TRX90 like they do for the mini bike engines.

I would also love for some of the builders that visit this site to jump in here and inform those of us scratching our heads as to what will work best for power and for longevity.

[fastlx]

Pappy, thanks for the info, I think I will do somemore looking around and report what I find. Thanks again. I am going to put a call into Rob tomorrow and see what he has too say.