Modded my Son's T-Rex 90
 

Being that the stock T-Rex airbox is utter crap it caused enough dirt to ruin the rings on the piston. SO I said to myself why not make it faster while I'm at it.

I put on...

-Exhuast
-24 MM carb (I think it's 4 mm bigger over stock)
-Ported cylinder (new one)
-Race Head
-Supposed 110 cc piston (it looked identical to the stocker so I don't think it's really that big)

Here is the catch. I've seem to have lost the bottom on this thing. When you rev it the motor winds up but it doesn't move until about 1/8th - 1/4 throttle. However....once you scream it (long enough mind you) it hauls buttcheeks!! I let two my buddies ride it on the street today and they were blown away but the top end this thing has. It's quite impressive, but I was looking to get more bottom out of this thing. Anyone have any ideas on what I can do to bring this thing back to it's stock grunt?

Modded my Son's T-Rex 90
 

The larger the carb the more top end you will get but you will also lose some botom end . You need to find out if they ported your cylinder for low mid or high, those are the two things that can effect the power band hope this helps

Modded my Son's T-Rex 90
 

I believe that to get the most out of these little quads you need clutch mods too. It sounds like the clutch needs to kick in faster.

I would also look at gearing it for more torque.

Modded my Son's T-Rex 90
 

You need some clutch work David. Try some stiffer clutch springs, a stiffer torque driver, lighter roller weights, shimming the variator and adjusting the transfer to your kids weight and not yours.
The cylinder you got is probably a 53mm cylinder which took your Dinli from a 95.6 cc to a 99cc.

Modded my Son's T-Rex 90
 

Hey TRexTommy51 how did you know my name?

I took it down the street again it and kicks in HARD!!! Again it takes forever to get there. I'm getting a Transkit which i was hoping I'd get today but it hasn't arrived yet. The vendor that sold it to me said that it should have more grunt than it did stock (which I thought in stock trim it was torqey) with the transkit. When I put it on I'll see. I didn't bother asking about the porting info or whatnot. I'll wait till I get the transkit and post what happens. He does have a clutch kit available (like around 250.00 or so) for this automatic quad. If trans kit doesn't work I'll look into that.

Modded my Son's T-Rex 90
 

Oh and Trextommy I'll look into those options too. The top end is nice.. but not what I was looking for.

Modded my Son's T-Rex 90
 

I had the FBI run a search on you. You've been a bad boy!![img]i/expressions/face-icon-small-happy.gif[/img]

Modded my Son's T-Rex 90
 

Yes I've been bad. How do you know so much on the T-Rex have you worked on any yourself. I should have gotten my trans kit by now. I think I'm bothering the crap out of the vendor. If it doesn't arrive tomorrow I'm going to rant a little. I hope that resolves my problem...


NOw...

How did ya know my name?

Modded my Son's T-Rex 90
 

We all know your name Dave......


Let us know how the transkit works out...

Modded my Son's T-Rex 90
 

I still didn't get it today. GRRRRRRR... I called the guy. His name is Kerry Simmons at Simmon's Racing. I did ask him how does one go about putting that in. I might start tearing off parts of it now. Said I needed a vice, a 14 and 17 mm socket, a LARGE channel lock and something else I can't recall. Hopefully it will get in tomorrow and the kid can start riding a track this Sunday.