there really arnt ALL that many differences between a modern CRF and TRX machine... other than the more aggressive ignition timing and bumpstick over a stock TRX....
remember...the 06/newer machines all carry a very similar valve train design.....Ti intakes, same style of porting, but w/o the CRF cam (which by the way is not larger or more aggressive than the HCII, it is actually slightly less aggressive, but makes for some serious Acceleration vs more mid/top end).... it is basically the platform these engines ride in.... take your TRX engine out and put it in a MC frame....then perform the same tests.... watch the difference in performance....
Also....someone mentioned how much faster stock for stock the YFZ450 and Zuke 450's are over the TRX450R... well, that aint really true..... a bone STOCK YFZ and Zuke is about identical to the TRX........ the TRX however just requires a little more work to OPEN them up.... the YFZ can be opened up rather easily due to a dual cam design.... your able to simple 'twist' the cams in order to increase the valve overlap and duration... whereas on the TRX you have to purchase a NEW cam in order to accomplish the same task....they did however re-map the ICM for better performance once the Sub Harness is installed (green wire mod)..... (HRC kit for example)...the Zuke is the easiest to mod....cuzz all you really need to do is purchase the 'cherry bomb'....cuzz all the mods are already done for you.... you just need to allow the computer to work... ignition timing and fuel mapping....which can all be done electronically thanx to the FI..... I hafta assume once Honda goes to FI, they will have a similar mod.... you will get the cam and ICM and pipe STOCK but DE-tuned...then a cheap plug in 'tuner' (cherry bomb) will open her up......or at least I would HOPE Honda would go this same route....
**06 450ER**... #3 (Dale lives on)
86TRX250R (mostly stock 66mm bore x 72mm stroke) **for sale**
86TRX250R (ESR310 72.5mm bore x 72mm stroke '298cc' fully modded) **SOLD**
88TRX250R (ESR330 77.5mm bore x 74mm stroker '345cc' fully modded)
HRC kit (all but gone)
Hot Cams stage III
Okie porting w/ATP CV4 springs (36mm Ti/31mm)
Venom/KBR N2O Porting w/KW springs (37mm/31mm)
Venom/KBR 487 100mm 14.25:1 piston
Cold Fusion Nitrous**
Venom 'QP' pipe
ESR Pro Series pipe
ESR modded intake w/RAT stack
42mm Taper-Bored FCR
Direct Drive clutch lockout, CR500 springs
GT Thunder-Link w/Durablue Lowering Link
Durablue Anti-Sway Bar
Modded shock mounts
Rage Modded Tranny
Jetting/Carb: #168, #45slow, NGPR needle 3rd clip, #55 Leakjet, Pilot 2 turns out.
Jetting/N2O: 22N/21F (22hp)
*STU Comp Cut 21x12x8 (6) paddle 'Padla Brats' on Douglas Blue label 8x8.....
Thanx to: Venom/KBR (Mixxer/Kam), Rage ATV (Dee), Sredum (Chris), and many ORG members