gpx in trx 90

[kirks11]

hey i got a 97 trx 90 right now it has a 105 bore kit and a custom made exhaust, well its not enough for me im wanting to get one of the gpx motor probably the 155z i want to see if anyone else had tried and and if it will fit or not. thanks -jason

[kirks11]

dont tell me im the only person who has ever wanted to try this anyone out there with some info??

[ROBBSRACING]

I am sure someone has done it. Its not popular with the racers because most sanctioning bodies require OEM TRX engine cases to be used.

[kirks11]

yeah, i figured someone had done it its just a project for me

[buildinitnow]

Stuck the 125 lifan motor/combo in over the weekend in a 98 trx90 stock chassis............. its been a nightmare.

What has worked: motor in engine, trx90 intake and stock carb, exhaust, motor mounts all lined up......

Not worked: combo carb, intake tube, air filter, clutch cable, throttle cable, 26mm carb, and the kick start lever, wiring harness...

We did ride it around, but we did not have the correct jets for the carb. I had a 125 pit bike on hand to grab the parts we needed off of that: wiring harness, kill switch............

I'll give you a review when we get that bigger carb on there and such...........

[woodsracer144]

Originally posted by buildinitnow
Stuck the 125 lifan motor/combo in over the weekend in a 98 trx90 stock chassis............. its been a nightmare.

What has worked: motor in engine, trx90 intake and stock carb, exhaust, motor mounts all lined up......

Not worked: combo carb, intake tube, air filter, clutch cable, throttle cable, 26mm carb, and the kick start lever, wiring harness...

We did ride it around, but we did not have the correct jets for the carb. I had a 125 pit bike on hand to grab the parts we needed off of that: wiring harness, kill switch............

I'll give you a review when we get that bigger carb on there and such...........

im not sure what one of you's it is but i know whos account this is, why did you just take the whole harness off the bike, with the carb and all that and put it in the 90? i know im not there so i cant really see it in person. what size carb was on the pit bike? that 26? as far as a kicker your gonna need another kicker knuckle, then i dont know if that mig is up there or down in Chippewa or where but then take that and get a small chuck of round stock and weld the one knuckle to the end the other on the other end, just so you can clear the frame. is this for luke's 90 or mat's? are you going to run the 90's exhaust or the bikes?


Kirk check out Orion Pit bike sales, i think its like opbs.com or something like that, they have a spot just with race motor, if you had the coin i would look for a crf150, the air cooled would be easiest but what ever works. i know theres alot of the china crap when you get in the pit bike motors but there are some really good set ups as well.. i think you would get some really good deals if you would join a mini fourm... ( http://planetminis.com/f11/ ) that will take you right to the honda stuff... there are some sick set ups on there, i had 2 bikes one was a SDG 110 that was a strong bike... then i had a Drz/ klx 110 that was tricked out with all the bells and wistels... they both were fast bikes... that sdg was one hell of a bike out of the box, i really miss it but the trans was going on it... sold it to a buddy and he put a 160 in it i think...

[TEMPESTRACER1]

So the lifan kits are no good for the TRx 90s?

[woodsracer144]

Originally posted by TEMPESTRACER1
So the lifan kits are no good for the TRx 90s?

im not really sure. i know some are a all down shift patteren, some are one down 3 up some are 4 up. the all down takes time to get use to, the one down 3 up some times is a pain cause you fine N when you dont want to and then when you want to you cant find it to save your soul. some of them will only start in N cause of Decompression thing that activates when the clutch is pulled in... or something like that, it wont start when you kick it over in gear and clutch pulled in... why i dont know... just take your time and look things over and join a mini moto fourm they know alot more then i do... i think i would take a GPX 160 over a lifan

[davetat2]

tried lifan and gpx go with the lifan much better quality harder to get power from(longer stroke) but lasts longer and more torque no its not honda if you want the best money no object check out
www.tjr-motorsport.de they built the land speed record holding 142cc engine think it was 106 mph