Fxr 150 ?

**Retro XR guy** · 18th December 2006, 09:31

Hello all.....new to this forum I was wanting to pick brains on any dealings with the FXR 150....my son and I race karts and at present are using trusty old XR200 power plants which are getting old and tired.There are quite a few other XRs to compete against which makes racing very close so was wanting something to give me a leading edge,I have been looking into the FXR and it seams they produce a little extra power against the standard XR200 so could be a good start for a new power plant.
So my question to others is this ....is there much that can be done with the FXR to tweak it ....are there many after market mods.....are they reliable....can they take some punishment.
I am coverned to 205cc and the main must for me is that whatever I choose have electric start ,so someone may have another sugestion on another motor....thanks for any help and Merry Xmas

**Grub** · 18th December 2006, 11:51

Forgive me if my numbers are not 100% accurate.

I'm assuming that you're in a 150 class? The FXR motor is a 4 stroke generating about 25HP. The 2 stroke version as found in the Suz RG150 is 37HP .. so heaps more. Since you don't say what the class rules are, I don't know if any of that is relevat

Brett

**Retro XR guy** · 18th December 2006, 12:21

grub...I have done some looking and they FXR is rated 20 hp (14.5kw)....I am limited to 205cc in my class 2 or 4 stroke....are those wee 2 strokes electric start?

**Flyingpony** · 18th December 2006, 12:32

are there many after market mods.....

I've heard there are some after market cams for them.

are they reliable....

Yes.

can they take some punishment.

For those who trash theirs on the track, they apparently can sit on the red-line all day without problem.

**xwhatsit** · 18th December 2006, 14:55

Uhuh, there are plenty of 150cc 2-stroke electric start bike engines. They make shit-loads of horsepower compared to 4-stroke equivalents, but they'll make bugger-all power until high in the rev range; when I've been karting before, on certain tracks, the 4-strokes were doing better than 2-strokes despite being down on power, as they could get out of corners better. Not sure, but there should be quite a few 200cc 2-strokes around too, from dirt bikes, but I don't know about electric start.

**Retro XR guy** · 18th December 2006, 16:30

I would consider 2 stroke (but prefer 4 as you described the power usage on the nose)....tell me what are the elec start 2 strokes?.....cheers

**Tim 39** · 21st December 2006, 19:59

I don't know of any 2 stroke electric start roadbikes (not sure about off road), they all seem to be kickstart

**Str8 Jacket** · 21st December 2006, 20:39

Originally Posted by Retro XR guy

I would consider 2 stroke (but prefer 4 as you described the power usage on the nose)....tell me what are the elec start 2 strokes?.....cheers

Ah dont worry about the kickstart. 2 strokers are awesome, wish id never sold mine!!

**Buddha#81:Me** · 21st December 2006, 21:47

I hate to deflate your bubble but 15hp is all you will get from a bog standard FXR. There are cam's and CDI's avaliable, you might get it to 25HP before reliability becomes an issue. Your hot XR200 will be pumping out more HP. If you decide to go with the fxr stick with a stocker and thrash the shit out of it. The FXR engine will probally weigh 20-30% more than the old Honda.

**vtec** · 21st December 2006, 22:17

Damn man, if everyone in your class is racing something less powerful than an FXR150 engine, when the rules are 200cc 2 or 4 stroke, then all I can say is that nobody has thought particularly hard.

The RG150's and KRR150's are raced in Streetstock alongside such legends as the CBR250 (4 stroke screamer), and they are only a bit down on pace. Seriously get hold of an RG engine, and you will clean up... not sure if they are kick start or electric or both, but I know that they are capable of up to 32hp at the wheels with just jetting adjustments.

**disenfranchised** · 28th December 2006, 08:23

Aprilia RS125??
2 stroke, Electric Start, 29hp

**Str8 Jacket** · 28th December 2006, 08:25

Originally Posted by disenfranchised

Aprilia RS125??
2 stroke, Electric Start, 29hp

Road legal though? Im not to sure that they are in NZ? Could be wrong though....

**disenfranchised** · 28th December 2006, 08:27

Originally Posted by Str8 Jacket

Road legal though? Im not to sure that they are in NZ? Could be wrong though....

That doesn't matter, he just wants the engine for a kart it seems

**disenfranchised** · 28th December 2006, 08:36

Looking at the RG150, it does win on power.
Overall a 200cc engine from an endurance style bike might be better
comparing it to the RG150
http://www.motorbikes.be/en/compare/5419/5114/

More torque, lower revs required, same power....probably easier to get hold of too