Opinions on what I am doing to my bike

CalebG0770

CalebG0770

New Member
#1
#1
Currently I am running an ungoverned predator 212 with a Amazon vm22 carb and a straight pipe with 18lb springs on my Coleman ct200u trail I just ordered some sun f tires that are an inch bigger and a 40 tooth sprocket I also have a torque converter and I’ve done the math and I’m pretty sure I’m gonna be doing about 60 miles an hour is this smart or stupid I can’t tell because I just wanna go fast as heck on a little machine
 
Triley41395

Triley41395

Well-Known Member
#2
#2
CalebG0770 said:
Currently I am running an ungoverned predator 212 with a Amazon vm22 carb and a straight pipe with 18lb springs on my Coleman ct200u trail I just ordered some sun f tires that are an inch bigger and a 40 tooth sprocket I also have a torque converter and I’ve done the math and I’m pretty sure I’m gonna be doing about 60 miles an hour is this smart or stupid I can’t tell because I just wanna go fast as heck on a little machine
Click to expand...
Yes it's stupid, but sounds fun. Get a helmet...
 
CalebG0770

CalebG0770

New Member
#5
#5
Davis said:
Doubt that motor could turn that gear ratio other than pointed downhill. You should shoot for at least a 6.1 gear ratio.
Click to expand...
I’ve been running a 5 to 1 gear ratio for about 8 months and it’s been doing great I actually don’t like how much torque it has cause it wants to pickup the front end that’s why I’m going down to a 4 to 1 ratio for more speed and less torque
 
Biffmini

Biffmini

Well-Known Member
#7
#7
CalebG0770 said:
I’ve been running a 5 to 1 gear ratio for about 8 months and it’s been doing great I actually don’t like how much torque it has cause it wants to pickup the front end that’s why I’m going down to a 4 to 1 ratio for more speed and less torque
Click to expand...
 
SAS289

SAS289

Well-Known Member
#9
#9
The speed calc (the math) isn't always accurate because engine power and load are not in the equation.

5:1 gearing is already not very good for performance against a 19 inch tire. 4:1 and a taller tire would be horrible and you would need a lot more road to get up to speed.

Another thing about this. What good is a slide carb when you are turning 3500 RPM or less? Just better throttle response and a little more torque than the stock carb? The slide carb should start doing its thing once you get into the 4K RPM range with a 60 tooth sprocket on there and you should see a higher road speed. Hopefully it will top out before you start breaking stock internals or even worse blowing the flywheel. Get a tach so you know what RPM you are turning.

I understand what you mean about the low end and wheelies. But there's a trade off. You may better control the wheelies with a smaller sprocket but sacrifice the rest of the bikes performance after you get rolling.
 
Last edited:
sparkwizard

sparkwizard

#10
#10
You need 5:1 or 6:1 with a torque converter in order for your engine to rev enough to shift the belt up and get into "overdrive" to go the fastest you can go. If you install taller tires, and gear it 4:1 behind the converter, you might as well have a 2:1 jackshaft and 5:1 rear gearing, because your converter will never shift up. It is acting as a clutch, and it will smoke belts.
Have fun and be safe.
Oh, and I agree with installing the stock carb and connecting the governor. Better control, better torque, no hassles and no stock parts letting go.
 
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