ok every1 will most likely sayy im lieing but i have a 2002 trx 90 it has a exhaust from a ttr50 on it i bent it to fit jet kit an a pod air filter. an with a gps zip tied to the haddle bars i got it to 45mph no down hill or anything im 225lbs. i alsohad a cop clock me at 41mph passing a car in a no passing zone an the speed limit was 30. but i know every1 will say thats impossible but whatever come over an ill prove it.

 

I clocked my son's 06 TRX 90 at an honest to God 43mph with me on it and I weigh right at 175. It was clocked with a GPS on flat, hard pavement and the unit is stock. The little booger will run.

Now having said that, the old Honda 90s motorcyles from the 60s will run as fast as 60 to 65 mph and hauled 2 people around with no problems.
My cousin had one when we were teenagers and we rode the living daylights out of that thing!
The Honda 90 engine is one tough motor and Honda has been building that basic design for years

 

I have a 2003 Trx90x (completely stock besides rear tires) and it easily goes 35 mph on dirt! Thats with a 120 pound rider.

 

I just installed a 110cc elec. start full auto with reverse in a 94 trx90 dratv has my sons bike on his customers bikes pics the mad max one

 

Put a 110cc in it easy swap

 

I have a spare trx motor right now I am willing to sell