79cc Predator build

GoldenMotor.com
Dec 11, 2014
628
14
18
Tucson
This bike is not street legal in our area. It is a shop project done for a repeat customer that already owns 2 two strokes and a 49cc four stroke we custom built for him. The basics of the build are as follows: 79cc Predator, governor removed, custom intake manifold, NT carburetor with main jet drilled and high flow filter, oversized kit tank & fuel valve, automotive fuel line & filter, adjustable 4 stroke mount with base plate strengthened and lengthened 1.5" rear mount block flipped, custom 3rd /motor mount/exhaust brace on top, kit throttle & kill switch, full custom 7/8" exhaust fully wrapped, pit bike muffler, mini bike jackshaft plate with 5/8 shaft, Max Torque go kart clutch, mag wheels with direct mount rear sprocket, SUN high volume tires, Kulana frame/fork, C9 gel seat, solid aluminum quill stem, 4" riser bar, foam grips, ultra wide bottom bracket axle and crank, hydragraphics dipped motor tins, front and rear BMX calipers with special pads. Initial testing confirms the gearing is to tall which was expected, I am switching from a 44 tooth rear to a 56 and that should be really close. And it looks like a rear axle kick stand which was my last choice is the only one that fits. Other than those minor tweaks the bike came out nice and rides great. We have a plexiglass jackshaft chain guard not in the pics until we get the mount for it finished.









 
Last edited:
Dec 11, 2014
628
14
18
Tucson
We have an engine size restriction here in our state of 49cc or smaller to qualify as a motorized bicycle. To go larger you would need to be legal as a moped or motorcycle with lights, insurance, tag, registration, etc. Arizona has some pretty loose requirements for buggies and home built motor vehicles though so we have thought about tagging and insuring this one.
 
Last edited:

thingswithwelding

New Member
Mar 22, 2016
120
4
0
Long Beach CA
We have an engine size restriction here in our state of 49cc or smaller to qualify as a motorized bicycle. To go larger you would need to be legal as a moped or motorcycle with lights, insurance, tag, registration, etc. Arizona has some pretty loose requirements for buggies and home built motor vehicles though so we have thought about tagging and insuring this one.
Well, thats ok then. At least you can if you want to jump through those hoops. I just dislike when we build something and they dont allow it no matter what you do. Thats the real bummer. Again, at least is possible. Im actually interested in a blinker kit for my build. I want something I can work with though and make clean and custom. I dont mind sporting it but dont want to mount just any arrow that iluminates. Know what I mean? A nice old school chrome headlight can type too. All battery operated for now. I could just maybe get the kit and customize with various lenses and brackets and parts etc. Make it custom to where its hiddn and clean.
 

thingswithwelding

New Member
Mar 22, 2016
120
4
0
Long Beach CA
Motorized bikes in Arizona are 48cc or less and can not go over 19.99 mph without big fines especially if you don't have a drivers license.
You do not need a drivers license or a helmet if you qualify.
I have a question while we are here. On my build, its all mostly fabricated by myself. My bottom bracket was purchased as a blank shell online. My headtube was made by me. They both have no serial numbers. The only part that was a previous bicycle is small portions of the rear chain stays and the rear dropouts. They were from a Nirve switchblade frame that my buddy chopped and customized. He was going to trash them so I kept them for my project. And those pieces have no numbers as well. All the bars I bent and rolled myself. So my question is, ***How can I register my motorized bicycle that I made if I have no serial numbers to write on the California license plate form? I mean, Its my bike. I made the thing. Are they going to say I need a manufactures license to stamp numbers in it and Im out of luck?
 
Last edited:

thingswithwelding

New Member
Mar 22, 2016
120
4
0
Long Beach CA
This bike is not street legal in our area. It is a shop project done for a repeat customer that already owns 2 two strokes and a 49cc four stroke we custom built for him. The basics of the build are as follows: 79cc Predator, governor removed, custom intake manifold, NT carburetor with main jet drilled and high flow filter, oversized kit tank & fuel valve, automotive fuel line & filter, adjustable 4 stroke mount with base plate strengthened and lengthened 1.5" rear mount block flipped, custom 3rd /motor mount/exhaust brace on top, kit throttle & kill switch, full custom 7/8" exhaust fully wrapped, pit bike muffler, mini bike jackshaft plate with 5/8 shaft, Max Torque go kart clutch, mag wheels with direct mount rear sprocket, SUN high volume tires, Kulana frame/fork, C9 gel seat, solid aluminum quill stem, 4" riser bar, foam grips, ultra wide bottom bracket axle and crank, hydragraphics dipped motor tins, front and rear BMX calipers with special pads. Initial testing confirms the gearing is to tall which was expected, I am switching from a 44 tooth rear to a 56 and that should be really close. And it looks like a rear axle kick stand which was my last choice is the only one that fits. Other than those minor tweaks the bike came out nice and rides great. We have a plexiglass jackshaft chain guard not in the pics until we get the mount for it finished.









Can I ask how that Max Torque clutch is working for you? Is it smooth from start to cruising speed and all the way around? Im hearing my clutch that came with my AGK clone jackshaft kit is terrible. I might be in the market for another clutch and read Max Torque clutches is a fix for this. Thought Id ask since your post says you are running one on this build. Thanks
 
Dec 11, 2014
628
14
18
Tucson
The laws in California are different and I really have no knowledge of them. The Max Torque clutch has some chatter with the current gearing but it is way to tall. I will be testing with a 50 tooth on the rear today and hopefully that eliminates a lot of the chatter. This bike is just a weekend toy and in the end we may sacrifice a bit of low speed performance to keep the low RPM high speed cruising how it is now. The Max Torque is just a consistent cheap clutch, the tunable race clutches are in a different world and this bike will probably get one eventually.