Moe's Motovox drag mini.

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moetrout

Active Member
#21
#21
Finally getting around to making some of the changes I had planned. I have lengthened the wheel base by extending the rear out 7" and lowered the rear end by almost 4 inches. Still thinking about raking the front end a few degrees. Did a physical measurement of the trail and it looks to be around 4 inches. The stock rake is somewhere around 30ish degrees. If I rake it I will have to make longer forks as the frame is less than 3 inches off the ground in the front.

I started tearing down the motor. I need to do an in the hole measurement and then I can start ordering parts. I bought a tach and did some high speed runs to see what the rpms were before mods. The new tach showed 5800 rpms, the goal is 7000.
007.JPG
 
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M

moetrout

Active Member
#23
#23
Already had the flywheel and CS cam with 18lb springs, and carb was jetted bigger, all by the previous owner. I am putting in the billet conn rod, going to 22 lb springs at the suggestion of Dyno. I found out during disassembly that the PO had done some porting. That work looks ok, so I will probably just clean it up a little. The CS cam is only rated to 7000 rpms so I don't think I will get it to 9000 with that cam. I've been holding back on the carb. I want to see where it's at after I get it back together and then choose a bigger carb. I'm thinking .650 bored stock carb or a 22mm mikuni.

Got some more work done on the frame this weekend. New forks, mounted the brake bracket, and worked on an idea I had for a nifty kick stand. The kick stand does not work and I need to figure some things out still.
 
M

moetrout

Active Member
#24
#24
The beginning of my aluminum gas tank. Thanks to my buddy Art who donated the 3 inch tube and end plates. Now I am just trying to find someone to weld it for me.

 
David wulf

David wulf

#25
#25
Mr moe the bike looks trick ass hell , for Chinese. Lol
The forks look good . As far as rake I would leave it at 30 degrees, it will be plenty stable with that rake . Anymore an she starts to not turn as well .
 
M

moetrout

Active Member
#29
#29
Well, I always thought of it as a golf cart tire, but no, not really. That's what leather is for right? Seriously though, I would like something better. That tire is 15" tall. I haven't found a 15" tall slick. To change the tire size for me means changing gearing too. It's not just a tire change if I want to maintain gearing and speed. I have been looking into what I can get in scooter tires, the ones that look like mini sport bike tires. Ideally I'd like an aluminum rear rim with a 3 or 4 inch mini sport bike tire as close to 15" tall as I can get. Got any suggestions?
 
M

moetrout

Active Member
#31
#31
Getting ready to reassemble the engine. Governor was removed by the PO, but he left the arm/shaft in the top of the block, so that is removed. Removed the governor gear form the crank. Not seen in this pic is that I plugged the governor shaft hole with a 1/4 20 bolt. I could not find the right tap in my toolbox so I let the bolt do the tapping and it worked out just fine. I have also soda blasted the block, side cover, valve cover and head. The soda blaster did a great job on the carbon build up in the exhaust port. I have already cleanup the ports by hand with emery cloth. Next up is to polish the exhaust port and then scrub everything clean with hot soapy water. Then finally I can start putting it back together.
 
M

moetrout

Active Member
#32
#32
some updated random pics:

Finished porting, was a little more aggressive on the intake port than the exhaust port. Smoothed out some of the rough porting done by the PO:

Reassembled into a roller. Sanded, primed and painted satin Navy blue. Left the forks bare steel and only painted the triple tree. Polish the forks for a little shine:

Hurt my back this weekend and motor work stopped right after putting the head on. Starting to get exciting to see the end product of all my work. I've had a vision in my head of what I want it to be and only hope I can come close to that with the skills I have. I am a computer programmer by trade so I am not use to doing engine and metal fab work.
 
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M

moetrout

Active Member
#34
#34
Updates from this weekend. Just need to figure out carb linkage and I will be ready to fire it up.

A better pic of the frame with new color:

Silly puttied valve to piston clearance check:

Assembled engine, removed the OHV on the valve cover and polished it......you can still see the OHV if you look real close:
 
M

moetrout

Active Member
#35
#35
Carb linkage was easy and that is done. Updated pic with the rough seat and new aluminum tank mounted. 2 things currently blocking completion. First is the brake mount. It's a little crooked and too close. I've tried to bend it back just a little but that is not working. I am think about cutting it off and remounting it with a new bolt mounted bracket. My hope is that would make it easier to precisely mount it where I need it. I would use bolts and an axle style spacer cut to the proper length. Crazy idea? Should I just re-weld it? The other issue is the new aluminum tank. The filler neck got warped when it was welded. The cap will not go on. At first I thought I just needed to chase the threads clean, but last night I measured and it's 48mm in one direction and 49mm in the other. Anyone have any tricks for that? My thoughts were squeeze it back to round with big pliers, heat and squeeze or heat and then try to thread the cap on to correct it, lastly cut the threads back on the high side by .5 mm on each side for a total of a 1mm reduction. I dunno, I could use some opinions on these things before I do something I regret.

 
M

moetrout

Active Member
#36
#36
Got my gas cap fixed. I used thread files and took a half millimeter off each side until the gas cap fit. The threads were a little rough so I used valve lap compound (coarse, then fine) to smooth them out. Gas tank is mostly done, just need to go to the hardware store and pickup a hose barb. On to the brake mount problem.
 
M

moetrout

Active Member
#37
#37
Repainted the frame to candy blue metal flake. Tank is mounted. Seat covered with blue jean and mounted. Might do some stainless steel trim on it. LED lights on order. Sent the head out to be milled .050". Brake disc is not straight. Have a new one to put on.
 
M

moetrout

Active Member
#39
#39
It's been a long delay from switching from a .010 head gasket to a .045 head gasket and having the head milled .050. With help from my good friend Rick on Saturday we reassembled the top end, checked PTV and PTH clearances, and mounted the motor. Somewhere along the way I lost the exhaust nuts so we did not get to start it. On Sunday after 2 trips to the hardware store for the exhaust nuts and then later a hose clamp for the gas line I was finally able to start the motor. It came right to life but idled high. A small tweak to my newly made carb linkage and she idles just fine. Sounds mean too! I still need a kill switch, brake cable connected, and lastly the chain put on, then it will be ready for a test ride! After running the motor a bit my newly made gas tank started vibrating loose so I have to come up for a fix to that as well. Here are a couple of updated pics.
 
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Dukmang

New Member
#40
#40
I'm really digging this build. There's a Motovox on the local Craigslist that I'm thinking about pulling the trigger on. I'm also wanting to build a drag oriented bike and it looks like the Motovox is a decent starting point.
 
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