Planet Minis

fireman_343

So, after racing my NSR50 stock, then jumped up to a 63 big bore kit for the last few years, I thought it was time to try out a 4 stroke...
Read up about it here, News LOTS of pictures and what not!

Still need to put a few spacers and new bolts in the motor, but that is getting done tomorrow!

-Brian
TEAM QUAZZYMOTO RACING # 4

shw911

Nice website, Brian.
The bike looks awesome. Do you have any videos of it running with the new engine?

fireman_343

Thanks... I'll have a video of it running very soon! I'll post it up when I get one.

supernes550

great info! it'll be useful for those who plan on doing the same swap.

any plans on producing the brackets?

fireman_343

I've been thinking about it.. if I can get a friend of mine to cut them out with his CNC then yeah!!!
More on that later, after the racing season is over!

FourDoor

Thanks for sharing and taking lots of pics. Now on to the questions:

How much HP is the XR100 motor with the BBR kit supposed to put down?
Just to confirm, it was just that small little 1/8" section on the old mounting section of the frame that had to be cut? Everything else pretty much bolted on to place?
Budget wise, how much did the new motor (minus the exhaust) cost?

supernes550

if you can stay with in or below the price of the jdm kit it would be cool.
good luck with the season. that thing looks like a blast to ride.

fireman_343

FourDoor, a stock XR100 puts out a little more then 7hp at the rear wheel... the BBR kit puts an extra 2-3hp depending on what cam you use, exhaust and all that other stuff plays a small roll in it as well. I'm hoping that after I do a 6mm stroke, the Powroll cam that I'll be above 10HP at the rear. Any more then 14hp on these motors and the tranny becomes a problem... so I've heard.
The major gain in doing this swap is the amount of torque you'll get out of this motor... with a high compression piston and a stroker kit, this thing will rip!

And yeah, after I made my own mounts, I just had to cut that small part off the bottom, where the stock 50cc motor mounts to at the bottom, and it was good. About the size of a thick washer. I did end up putting a thin washer in there, just to keep things tight and not "pull" in the bottom of the frame too much when I bolt down everything nice and tight.

I've got it broken down cost wise..

$200 for 2 XR100 motors, one was a 89 the other a 02.
$250 for the BBR120 kit still in the box... got it off a friend, but they are $275 new
$200 to a friend, for some parts that I needed, head, flywheel, CDI, etc..
$35 for a EBC clutch kit
$120 for more parts from service honda... small things that I needed, gaskets, bolts, timing chain sprocket and tensioner, flywheel cover, etc...
$250 for the custom exhaust to be bent.
$45 for the exhaust can on ebay
--------
total is $1100.. I sold all my 2 stoke stuff and a few college school books to pay for the conversion! I've got around $100 left!

FourDoor

Thanks for the breakdown fireman. Its nice to see the costs of the entire swap as I always neglect to factor in the parts after the initial main purchase of the motor.

10hp at the wheel with the torque should be awesome. Keep us posted on any other issues or other nice surprises you run into running this motor. I'm still heavily leaning on the Lifan/GPX chinese motors for my future swap but am very interested to see how well your XR100 w/ BBR kit holds up an performs. It may just convince me to go back to the right side and spend the extra $ on a true Honda motor.

fireman_343

Yeah, I plan on taking it to a dyno shop in town... We'll see what the "true" numbers are. Before and after the stroker and race cam!

firepower354

Cool swap! I'm a big fan of the uprights

I'd be tempted to get a good head before a stroker. The stock valves and ports are tiny. Maybe an 80 trans for a cheap close(r) ratio box, and a lighter flywhel or inner rotor?

fireman_343

The flywheel is already lighter, I see no need for a 80 trans yet.. and I'll put a kitaco head on when I get some more money! Stroker is only $250, the kitaco head is over $500 new!!!

firepower354

Where'd you get a $250 stroker? I know this fat old guy needing some cheap torque

fireman_343

POWROLL PRODUCTS FOR THE HONDA XR100 2001-CURRENT

A 6mm Stroke is only $250, you already know you'll have to split the cases and ship out the crank, but I've already got all the stuff to rebuild the bottom end when I split the cases... only extra cost is going to be the shipping.

Momo

If you got sample parts or drawings I can make them and anodize them, if you want.

Luckystar64

Looks awesome Brian! You get a chance to ride it at all? The exhuast looks awesome too. ---T

fireman_343

Tony, Kent is coming over this weekend to help me put some stuff together.. I should have it up and "running" by this weekend, and make the 1st race Aug 17th!

Luckystar64

What kinda stuff? Did you get it on the dyno yet? You should use the dyno to get a reading on Kents' stock motor first.

How does a dyno calibrate itself for wheel size and gearing? Or do you have to use the same bike and gearing in order to determine the power diff before and after engine work? --L*64

fireman_343

Kent is going to help me with the BBR kit..
And I'll put it on the dyno with the BBR kit, after this winter and the stroker kit and race cam, I'll put it back on and see what gains it made.

I know a stock XR100 puts out around 7-8hp depending on where you are, what dyno is used and if the Gods allow for a good run, etc.. I'll be happy with 10HP if I can get that out of it with the mods I'm doing. The light frame of the NSR, 12" tires, some gearing, the cool exhaust, etc.. will help it outa little bit off the dyno! Dyno numbers don't mean much, other then a number. The true test is out on the track! I ran my stock NSR50 with BD's 80 in the corners, but he would take off like a rocket out of them... it was like a 600 and 125 or 250 racing! Fun stuff!

firepower354

Ahhh. I was thinking (bad plan) they were $350. Maybe do an 80 crank instead? Lots lighter, same stroke. Shame to split the cases and not tighten up the gearing too