200cc Tecumseh Build

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Jasanabia

Jasanabia

New Member
Aug 7, 2011
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Goleta California
I finally got it running. I sanded the magnet and the flywheel some more until I got a spark with the NGK plug. Then I checked the valves again and as I was taking the valve cover off I knocked one of them off, so I put it back on and it started on the first pull with the valve cover still off. I have it all back together now except there's no oil in it. It leaked after I took the crankcase off so I have to jb weld it.
Here's the video of the grip shift throttle:
http://www.youtube.com/watch?v=aGp2ewKaOZY
 
Jasanabia

Jasanabia

New Member
Aug 7, 2011
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Goleta California
So the frame was kind of ugly, and the engine had some extra space, so I decided to try to make the bike shorter. On my first attempt I raked the forks out like a chopper.

Heres how it looked:

As you can tell, the design was really weak, as soon as I sat on it, the joint broke.
 
Jasanabia

Jasanabia

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Aug 7, 2011
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Goleta California
There is a wedge of 3/8 in thick hardened steel adding support. Now the front end is really strong, I've tried slamming the frame against the ground as hard as I can, and it seems fine.
 
Jasanabia

Jasanabia

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Aug 7, 2011
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Goleta California
Right now im just having trouble getting the chain lined up. I might have to use a file and modify the shaft so the clutch can slide on further, like a lathe. (with the engine running)
 
dracothered

dracothered

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Jul 25, 2012
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Howell, MI.
Jasanabia said:
There is a wedge of 3/8 in thick hardened steel adding support. Now the front end is really strong, I've tried slamming the frame against the ground as hard as I can, and it seems fine.
Click to expand...
I would also weld a wedge into the bottom bracket and the one going up to the head tube.
 
Jasanabia

Jasanabia

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Aug 7, 2011
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Goleta California
Exactly what I was thinking, already have the piece cut out, the same 3/8 steel.
I wasn't able to line up the engine with the sprocket, because of the key I can't use the centrifugal clutch backward like I had it. The plan now is to use the pedal crank bearing thing( I don't know what to call it) as a jackshaft.
 
Jasanabia

Jasanabia

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Aug 7, 2011
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Goleta California
To use this as a jackshaft, I had to extend the left side sprocket out far enough to line up with the engine. To do this I started cutting off the ends of bicycle cranks I had laying around and welded them together.



 
Jasanabia

Jasanabia

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Aug 7, 2011
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Goleta California
The throttle wasn't hooked up, but I wanted to try it, so I tied a piece of string to the throttle on the carb and started it. I sat on it and pulled the sting gently and it launched forward with a ton of torque. I had the idle adjusted a little high, so the clutch was engaging without pulling the string. Without giving it any gas, it accelerated to about 15-20 mph down the street. The back brake wasn't connected yet so the wire was dangling loose. When I turned around, the wire got caught in the chain and threw it off, and the chain slammed into the bottom of the carb, making a hole in the float chamber. Now i'm letting it drain into a bucket, I think ill have to get a new float chamber, it got pretty messed up, never a good idea to ride it before its ready.
At least I know it works well, the gearing seems good. The sprocket on the left side is slightly smaller, so it gives it some extra torque.
 
Dan

Dan

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May 25, 2008
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Moosylvania
Uber cool Jasanabia, love the DIY spirit.

Bummer about the minor mishap but think we have all done the "just had to try it before it was ready" thing.

Really think highly of the Tecumseh engines. A few days back, I dragged out our snow thrower with a Tecumseh engine. Had forgot to change the oil or empty the gas last spring but just had to see if it would fire up. (That and I didn't want to push it from a shed to the garage, up-hill, both ways)

Dang thing started first pull. In no way was it happy but did fire up. Changed the oil and gas and it purred right along.

What do you have planed for foot pegs?
 
Dan

Dan

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May 25, 2008
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Moosylvania
That is the cool thing about works in progress and DIYs. They are works in progress. Can't be wrong until they are. Then they only need some tweaking.
 
LabRat

LabRat

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Dec 24, 2011
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Ruston, Washington
Tecumseh Death Machine - part bicycle part machine - do not put an onboard computer on it or we are all in trouble!

"Death Machine" a 1984 British movie
 
Jasanabia

Jasanabia

New Member
Aug 7, 2011
76
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Goleta California
Got a new float bowl from a friend, and a new bolt for it after I broke the original one. I forgot those bolts are hollow with holes for the jet. Now the engine runs fine again, but I broke off the left side sprocket, the circuit breaker tripped about 7 times while I was welding it so I'm not surprised it didn't hold up. After I weld it back on the bike will be rideable, but still needs a chain guard and foot pegs.
I also got the back brake and the throttle hooked up, not using the top of a tin can anymore. It was too flimsy, now I have a strip of 1/8 in steel bolted on.
Ill upload pictures soon
 
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