Free power for your xr100

[esacco]

Thanks to all on this site!! Great info really appreciated!

I have a street leagal xr100 2002 so I needed more top speed.

I did the following:

BBR 120 kit

24mm carb

35/15 gearing

cut airfilter screen

Uni filter

cut air box

The last mods I did which were free were:

Cut the weld flush inside the header of the pipe.

Added a breather on the spark plug side of the valve cover. I used a 3/8 inch brass plummers elbow and clear hose and some foam stuffed in the end of the hose as a filter. I ran the hose up the frame so the oil will not flow out from residual blow by. I drilled the elbow out for better flow and used the largest tubing I could get that fit the elbow. I drilled the cover with a one inch drill bit and then dremmeled it to just a tight fit. I then JB welded it in and the outlet needs to face towards the front of the bike. It is the only way to route it so it runs up the frame to keep the oil from running out. If you are pro you can get a plummers tap for the elbow. This was recommended by BBR. This really frred up the pressure in the motor.

These last two mods made a significant difference!!!

I hit an honest 60 mph on a slight downhill and 50 on the way back. It is now perfect for general street use.

Thanks guys!!

[Campisi]

I'd like to know more about the second free mod you described. What does it do? Why do you need to vent the valve cover?

[zbnutcase]

Its all about crankcase venting. Every small Honda single i have seen has too small of a breather in the crankcase. What happens is too much positive pressure builds up and it forces oil past the rings at high RPMs. As you might imagine, increasing the displacement only adds to the problem. If anything you want a negitive pressure in the crankcase. 'nutcase

[hornetgod13]

Congratulations on the bike. I'd love to see pictures of it. My Son's bike has 15/46 gearing with a BBR120 kit and 26mm carb and recently had his up to 57.2 mph on a dirt road. There's still more speed in the bike. I still think your rear sprocket is too small. I think a 40 to 44 would better suit your street riding. That 35 is geared too high.

[socalxr]

Glad it worked out. ?

[esacco]

Thanks!

I will post some photos. I know the gearing is high yet I do not want to over rev the motor. You have to ride it to belive it as I feel it pulls it really well with the right RPM. If anything I can just drop to 4th and reduce the speed.

Overall it pulls great and I can still power wheelie in 1st and 2nd.. I need to tug on the bars though!

You helped me a lot as you did many of the mods I did.

Talk soon!

Eric

[esacco]

Glad it worked out. ?

It really made a NICE difference! Thanks for the advice! If I can find a deal on the BBR pipe that would be next using the stock slilencer.