Could not find a smaller front sprocket for my duaghters Kazuma mini Falcon 90 which has a 12 tooth front sprocket. So I decided to try something a little unconventional. I measured the chain and concluded that it was a 420, according to info I found on ekchain.com website. There is no direct fit smaller front sprocket I can find. Honda sprockets do not fit. JTsprockets.com lists their sprockets by application. Once you look up a sprocket it gives the dimensions. Found a sprocket from a Suzuki 50 atv that was close on dimensions but, the chain size was correct. Had a friend machine the center out of the kazuma sprocket and fit it into the smaller 11 tooth suzuki sprocket. This was a good plan untill I tried it on the atv. The chain follows the sprocket around untill it reaches the bottom of the gear where it begins to ride on top of the sprocket teeth. The distance between the teeth and the depth are the same as the original kazuma sprocket. Why won't the chain stay in the teeth? Is there something more to making a smaller sprocket for the same size chain? Anyone have a clue? Ordered a new repalcement from raceway to get the quad running again till I can figure out what to do.

 

Thats because it is a 428 chain.

 

Thanks 2manytoys. It was my understanding that the last two numbers refer the the width of the chain and not the distance between the rollers. 420 and 428 chain should be 12.7 mm between the rollers, which this one is. The width is 6.350mm. Not disputing what you are saying, just stating what I found when I was researching this. Thought that I had measured correctly. If this were true wouldn' t the 428 chain fit a 420 gear, just be a little loose because the gear would be narrower? Just looking for help because I don't understand why this is happening. Seems as if the teeth needed to be further apart when the tooth count went down. In holding the 11 tooth and the 12 tooth side by side the spacing and depth are dead on. Thanks again. Am going to remeasure everything and start over.

 

Yes the 420 and 428 have the same 1/2" pitch but the 428 is wider. Is the sprocket that you just put on thinner or thicker than the origional sprocket? My sons kazuma 110 had a 520 chain on it. I would think that if the chain is riding up on the sprocket the pitch is too small. I know the earlier suzuki lt80 had 420 chains but in 89 it switched to a 520 chain. MAybe its is a 520 chain. The 520 is 5/8" pitch.

 

Reading over your post again what you did should have worked. I know if you went with a 420 chain and 428 sprocket it would not fit but the lt50 did have a 420 sprocket and all you did was change the hub in the center of the sprocket it should have worked. Now im stumped. I know on my younger sons kazuma 50 it has the 420 chain but older sons 110 has a 520.

 

Thank you. I will send the sprocket to Sprocket Specialists liks John at Raceway suggested to me earlier. Maybe they can tell me why this did not work. I will post if I come up with anything. Thanks again.

 

2mayntoys,

My 2004 Kazuma has a 530 chain on it. Are you sure yours is a 520? If your is a 520, I would like to know where the sprockets came from. I have been trying to cross reference the 530 over to some make of bike so I can order different sprockets but have been unable to do so.

Cheers

 

I am sure mine had a 520 chain. It was the same as my Polaris. I really have never heard of a 530 chain. At least not on an atv.

 

Gave up on the sprocket idea for now. Got a new replacement from Raceway and atv is running again. Power problem seems to be solved. NGK plug and a replacement carb looks to have fixed it. Carb was replaced for a leak issue. Daughter is happy, so I am too. Thanks to everyone.

 

FYI: the early LT80's were 428 size.
New are 520.
I use #40 chain on my 428 sprockets.