100cc four stroke kit?

[Jesus Tralfaz]

That's a chain drive with two little sprockets, and sometimes with one chain or two chains inside. The chain maybe a #25. The clutch in the chain drive engine is usually this type of clutch. It can be hassle to get working correctly. It doesn't seem to spread out and grip much and the shoe material is hard and dry.

Much appreciate the info, thanks.

 

[ZekeNoScooter]

Anyone have any idea what the difference is between these two clutches? Is one belt driven, and one gear?
I've been interested in getting one of these for a while, and since I first started looking, the second one has appeared in the results. Thanks!

On the left is a pit bike type chain drive, that same housing is sometimes a single chain sometimes a double. Super cheap, around $30, usually. Bike Berry offers one for around $80, but is much nicer quality with an added freewheel to throttle down and coast. Single chain way too weak for motorized bike, IMHO. The other on the right looks like belt drive standard on most 49 and 54cc 4 stroke kits. It's alright, but pricey to replace if it breaks. I paid originally I think 160 or 180 for the whole kit, new trans was 120. (My backing plate broke in 2 driving down the road. Chinesium. You could see the casting flaw when you examined the break.). I think too, that that chain drive fits tapered shaft main and belt only fits straight shaft.
Back

 

[petesimon4]

Single chain way too weak for motorized bike

I removed the cover and looked inside. The single chain seems to be a #25 or very similar. Do you think replacing the stock chain with a 'H' heavy duty chain would be good thing?

 

[ZekeNoScooter]

I removed the cover and looked inside. The single chain seems to be a #25 or very similar. Do you think replacing the stock chain with a 'H' heavy duty chain would be good thing?

You won't make it worse. 25H and new is better than regular 25 and used. But, honestly, my opinion is single chain is for a VERY light setup. Tiny pitbikes or scooters. 10 - 15 mph. Go to a double chain. Not that pricey. Or the belt drive is usually pretty well built. I broke one once but it had a flaw in the casting.
Good luck!