FIRST BUILD- Vintage Bike, and TECUHMSEH 3.5HP GO-KART MOTOR

Hello guys! I'm Christian, and 16 years old. I have blacksmithed for 9 years and been welding for about 9 monthes. I had an old bike that my grandfather gave me and an old Tecumseh 3.5 motor that went on my Go-Kart. So what do I do? Combine them! I am a new member, and this is my first post, and my first build. So please give me any tips and ask any questions! Thanks! I'm taking the pedals off, so I guess it's legally a motorcycle xP
P.S. My mig welder is broke and I'm to lazy to fix it, so I am using my SMAW welder, so most of these are tacks till I get the mig welder working cause the tubing is so thin and all I've been doin is burning holes. xD So sorry if the welds look nasty.

Gear Ratio question: I have a 12 tooth gear on the clutch that will go to a jackshaft that will go from an 18 tooth (connected to the clutch) to a 52 tooth which will run to a 24 tooth attached to the rear tire. How will this perform, or should I use a different gear on the jack shaft? The 12, 52, and 24 are pretty permenant, cause I'm using the original 10 speed gearing the bike came with. But I'm just asking how one set up will act to give me an idea on how my bike will perform. Cause I am going to make mine shiftable using the shifter the bike has.
Wellp, Here it is!

 

[AnvilBlockForge]

Yes, 12t to 54t, then 12t to rear cassette.

Sadly, the multi-speed cassettes use thin chains, because of how closely the sprockets are. #415 chain prolly won't work.

Hmmm, will a brand new chain hold up?

 

[motorpsycho]

wow i can't beleive how many people are all over the laws of these things.
I'm so glad that i don't have to worry about that kind of stuff because where i live, it's legal to ride off road 4 wheelers, side by sides and golf carts on the roads. no one gives my bike a second glance.

 

[AnvilBlockForge]

The laws and cops arn't strict about it here. Partly because they don't know what it is, and because they arn't popular. I have a guy ride by my house every morning on his way to work. He uses a chainsaw motor and moves along pretty good. Seeing that he's been doing it for about 4 months now shows that the cops havn't takin it away. But yea, alot of states are very strict, sad. Can't have fun anymore. If we built 'em, we deserve to ride 'em!

 

[5-7HEAVEN]

Hahaha, didn't notice the "?"'s. Hahaha
I don't know if first should be the bigger gear, or smaller. Once again, I'm new to gear ratios. But this is their order from smallest to largest.
15, 18, 20, 24, 28.
So what will give me the most torque and speed? Cause don't I want torque to pull from a stop, then speed after I get moving?

And thanks for all your help! Your saving me from alot of headaches, and mistakes I'll have to fix later

1st(28t) = 10.11:1, to use from a standstill.....
2nd(24t) = 8.67:1.....
3rd(20t) = 7.22:1.....
4th(18t) = 6.5:1.....
5th(15t) = 5.42:1.....

First gear is biggest gear. Fifth gear gives speed.

 

[5-7HEAVEN]

Hmmm, will a brand new chain hold up?

I use an 8-speed shift kit for 2.8hp Tanaka engine. It works, but the bicycle chain gradually wears out, within a year.

Always carry spare chain, several extra links, master links and a chain breaker.

 

[AnvilBlockForge]

Okay! My saddle bags will be pretty large. So I plan to carry basic tools, spare tube, portable hand pump, and a spare chain at all times. Is there anything else I should include?

 

[5-7HEAVEN]

Cut the old floor boards off and put new ones n. I didn't like the old ones, lets face it, there were ugly xP So I used the plywood idea in Curtis's first link. Looks good! Later I'll stain 'em and put some polyurethane on em for strength and take the old floor mat in my truck and cut out some rubber grip for 'em!

How about pegs welded onto the frame?

Simple, unobstrusive, matches the frame.

 

[5-7HEAVEN]

Okay! My saddle bags will be pretty large. So I plan to carry basic tools, spare tube, portable hand pump, and a spare chain at all times. Is there anything else I should include?

How about a gas tank?

Will it fit inside your saddle tank?

 

[AnvilBlockForge]

Ahhh, spare gas! Great Idea. I have little gas cans that come in the same type of can Paint Thinner and Mineral Spirits come in. I'll make a bracket inside the Saddle Bag to keep that in

 

[AnvilBlockForge]

How about pegs welded onto the frame?

Simple, unobstrusive, matches the frame.

The wooden ones don't look that "off" when the motor is mounted. My motor is bulky, haha, so I had to stick the foot rests out to clear the motor. But I like the peg idea. I have a smaller bike I'd like to motorize, I'll use it on that one!