Will this work out fine?

[iVuo]

My friend recently passed onto me a mini bike that's been laying in his shed. It originally came with a 49cc motor. I have plans to weld in a new mounting plate and put in a 99cc predator engine. I've read if you gear these things wrong that you could easily burn up the clutch. I learned this the hard way with this engine on one of my go karts by putting bigger tires on the rear. So before I get everything put together I just wanted to make sure that the result won't be a burnt up clutch and more money out of my pocket.
Here's everything I've got into this so far:
15 inch tires,
11 tooth max torque centrifigual clutch,
And a 44 tooth rear sprocket.

I'm not very educated on this whole gearing thing and how it works. I've heard the bigger the sprocket, the quicker it is. And the smaller the sprocket, the faster it is, but the quicker the clitch goes. I've also heard that going with a 72tooth rear sprocket clutches won't be burnt up as fast.

So my question is, will this curent setup work out?
http://i44.tinypic.com/ibxmxj.jpg

 

[GregMartin]

That's a really tall gear ratio. I don't think it will work very well.
With regard to the rear sprocket, more teeth equals better acceleration and less teats equals higher top end speed. So you need to get the ratio right for you particular needs. Maybe a 60 tooth sprocket would be a good compromise.

 

[OzFab]

Weight is also a determining factor when calculating gear ratios. Just about everyone on this forum will tell you that a good starting point is 6:1; my current build now runs at 5:1 without a problem because:
1. it has small (10") tyres &
2. if it wasn't so big, I could pick it up by myself.

You may get away with 5:1 but, I agree with Greg, 4:1 is pushing it

 

[Oxymoron]

I agree that 4:1 is a bit steep. I'm running 5.41:1 on one of our mini bikes, and I like it right there. Although, we're probably throwing a TC on there very soon.... so, a static ratio will no longer exist.

6:1 seems to be that "golden ratio", but somewhere in the neighborhood should be fine. Obviously, tire size plays a major role, as well as weight, as both have been noted. All are equally important.

 

[iVuo]

Further investigation showed me that I messed up when getting everything right. My back sprocket is for a #25 chain, and the chain I have is a #25. The clutch I have is for a #35. Time to order a new sprocket and chain. I'll be going with a 60t sprocket (my rear hub is weird and it's the smallest sprocket I can find.

So if I'm correct that's a 5.45:1 ratio.
So with stock rpm I should do around 30mph. Not to bad.

But when this engine was on my go kart with a 72 rear, 11t clutch, and 16in tires, I was getting up to 45 mph.
So I'm guessing the governor is off and I'm getting around 5500 rpms. With my current set up, I should do about 45mph, if my math is correct. Which is still pretty fast for a mini bike.