Performance for the 50 CC XR50R ONLY !

[Hilltop Cycle/ATV]

OK,
My daughter races the 50cc Harescramble series in Iowa. She has to stay at the 50CC displacement in order to compete in that class. I am wondering what mods I could do that would help performance and still keep displacement ? She only weighs 70 lbs so, I think suspension will be fine.
Jets,Air Filter, porting heads, cam ? Which do you think would help ? And the most bang for the buck.
Thanks,
Raz

 

[Jaybird]

Leaving it stock, saving your money, and letting her learn how to race would be the most bang for the buck.

 

[Wolf]

I'd agree with Jaybird, but if you are looking for some easy stuff, here is what I did for my son's...
pod air filter, jetting, pipe.
The air filter change helped quite a bit in conjunction with jetting, the pipe was not nearly as effective.
I also added a taller seat for him to improve ergos.

 

[Hilltop Cycle/ATV]

What size jet did you go up to ? Did you drill it out or buy a bigger size ?
Thanks,
Raz

 

[Faded]

...here is what I did for my son's...
pod air filter, jetting, pipe.
The air filter change helped quite a bit in conjunction with jetting, the pipe was not nearly as effective.

Wolf, glad to see pod filter is working for you.

Also, you might try the larger XR70 carb (or one like it), the stocker is on the small side.

 

[Wolf]

The bigger carb was on my radar, will check into it some more.
I raised the needle by one position, and I think the main jet is a 58(?) I can't remember.

 

[Jasle]

suspension

Even at 70lbs the suspension is crap! It will beat the snot out of her. I think suspension mods would help quite a bit. Anyone on a big bike will tell you once their suspension was sorted they were way faster...Well the same goes for the kids. Nice suspension pays its dividends in the confidence department which in kid racing is about 99% of the deal.