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Old 07-31-2011, 10:00 AM
Pycngryn Pycngryn is offline
Motorized Bicycle Newbie
Join Date: Jul 2011
Location: Park City,Utah
Posts: 7
Thumbs up Greetings from 8000 ft.!

Howdy Howdy!
A huge” Thank you” to all those experienced motor bikers who post their knowledge and valuable info on this forum. Your time and patience is greatly appreciated by us Newbies.
I recently discovered motor biking while looking for a lightweight , portable, motorcycle or scooter to do vehicle shuttles to the end of river float trips. Living in the mountains at 8,128 ft. above sea level, I was concerned that the Chinese 2 stroke engine may not perform well or be able to handle the hills around here. After a lot of research and information gathered on this forum, I jumped into my first motored mountain bike build. There were a few challenges and a few setbacks. Finally, I’m became the proud father of an awesome, motored mountain bike that runs great, lots of power on the hills, 39+ mph on the flats and I have not yet gone WOT. Yee Haa! Here is my setup for :
-19 “ Specialized M2 Stumpjumper 8 spd. circa 1995 (very tight engine
fit, custom front mount)
- Judy Rock Shock and Front disc brake (absolutely necessary)
- 2011 Grubbe Skyhawk Silver Slant head 66 cc (milled,
portmatched ,copper gasket sealer)
- SBP Shifter Kit (extra Chain Ring spacer mods and added inside
- SBP Exhaust Expansion Chamber (up mounted position ,custom leg
protector and mounts)
- RT performance Carb 15.5mm from thatsdax - #64 jet (I gave up
on the CNS Carb)
- NGK BPR7HIX Iridium Spark Plug and upgraded cap and wire
- Custom front light system and lots of reflector tape for safety.
- Gel seat, fenders and thorn resistant tubes

Lessons learned after first build:
-Go slow, be patient, and do upgrade modifications upfront and assembly right the first time
-Install “Jump Stop” on shift kit correctly (I put mine in backwards, causing catastrophic derailments that wound up ruining the the front sprocket freewheel $69)
- Don’t waste time on getting the CNS carb to work, get the RT Performance carb from thatsdax. Aside from shortening the throttle cable and switching to a #64 Jet, it was plug and play. The rotating fuel intake, throttle cable noodle and overall small size helped a lot getting things to fit in this tight frame.
-Good brakes a must!
I can’t wait to get started on another bike for my girlfriend and then a boardtrack replica for this winter’s basement project. Until next time, -- build smart, ride safe, love life.
Attached Images
File Type: jpg The Red Barron.jpg (133.3 KB, 69 views)

Last edited by Pycngryn; 07-31-2011 at 10:05 AM. Reason: wrong picture
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