100cc four stroke.

[Zoom555]

Thats actually legal to do here without registration or license to drive here in New Mexico because the law designates they have the right to use the roadways in order to access road desert areas in order to go off roading in...Very unusual quirk in the laws that I have seen elsewhere in the country regulating off road vehicles.

Thats actually legal to do here without registration or license to drive here in New Mexico because the law designates they have the right to use the roadways in order to access road desert areas in order to go off roading in...Very unusual quirk in the laws that I have seen elsewhere in the country regulating off road vehicles.

I do not live near any sort of trails but who knows maybe it’s legal.

I contacted a seller of these kits in the past. The transmission is a 20/80 belt drive and the drive sprocket is a 15t. The engine produces 3600 rpm. This will give you a top speed of 23.7 mph on level ground.

That’s what I was worried about. It doesn’t give any real information on the setup.

Honda 49cc are spendy. I know it would run forever. I’m thinking I may do a kit with a belt driven clutch off eBay. The chain driven clutches are not very good from what I’ve been reading.

 

[Sidewinder Jerry]

I do not live near any sort of trails but who knows maybe it’s legal.

That’s what I was worried about. It doesn’t give any real information on the setup.

Honda 49cc are spendy. I know it would run forever. I’m thinking I may do a kit with a belt driven clutch off eBay. The chain driven clutches are not very good from what I’ve been reading.

If you got this kit, ran a 32t sprocket and pedal assisted it'd give you a level ground speed of 32.6 mph with 26" tires. Using 29" tires with a 32t would get you a speed of 36 mph.

I think these engines were originally setup for go karts. So going to a lighter vehicle such as a bicycle, they should be able to handle a 32t rear sprocket.

 

[cloakedvillain]

If you got this kit and ran a 32t sprocket it'd give you a level ground speed of 32.6 mph with 26" tires. Using 29" tires with a 32t would get you a speed of 36 mph.

I think these engines were originally setup for go karts. So going to a lighter vehicle such as a bicycle, they should be able to handle a 32t rear sprocket.

A claimed three horse power will be plenty and gearing can be tuned.

 

[cloakedvillain]

Four strokes generally have relatively linear torque and power curves. So if you get a gearing that launches alright it should power through the whole rpm range pretty easy. This is especially true with industrial engines. Famously torque-y with very little power when compared to revv engines but you don't need to ride the red line.

 

[ImpulseRocket]

I like that you have a choice of a belt or chain drive transmission. I have been considering a 4 stroke build for a while now just for fun. If it does indeed have a 4:1 primary reduction, that makes it fairly similar to most 2 strokes. Makes sense that is has 50% more drive teeth on the drive sprocket when it has about half the rpm to work with.

What I wonder is if you could tweak the limiter a bit without throwing a rod. I know the smaller 4 strokes don't have the most stout bottom ends, but getting it to say 4000 to 4500rpm peak with a better exhaust and maybe slightly bigger carb could make it a bit more fun.

 

[SirLurksAlot]

If it's typical of lifan engines, 4500rpm is doable for short periods with 4000rpm being fine for cruising. Some run their 152f 79cc and 154f 105cc up to 5000 or a bit higher, but i question the reliability of doing so. Unfortunately, no high perf engine parts seem to be available - carbs and exhausts yes, but no cranks, valves, cams etc. At least I've never found them lol

 

[DieselTech]

If it's typical of lifan engines, 4500rpm is doable for short periods with 4000rpm being fine for cruising. Some run their 152f 79cc and 154f 105cc up to 5000 or a bit higher, but i question the reliability of doing so. Unfortunately, no high perf engine parts seem to be available - carbs and exhausts yes, but no cranks, valves, cams etc. At least I've never found them lol

Look up arrow racing 79 & 99cc racing engines. I think this company is getting a reliable 6-7hp out of the 79cc

 

[SirLurksAlot]

Hmmm.... Lotsa arrow racing hits on Google, but not small engine/kart related. You say 6 to 7 hp out of a lifan 152f-3? I *want*!

Edit - found arrow karts. Lookin around now

 

[DieselTech]

Hmmm.... Lotsa arrow racing hits on Google, but not small engine/kart related. You say 6 to 7 hp out of a lifan 152f-3? I *want*!

Edit - found arrow karts.

Sorry its arrow motorized cycles. It's a 79cc predator 6hp. They call it a GT80 kit.

 

[SirLurksAlot]

Yeah, we're talking about a lifan 156f 98cc the op linked, the 154f 105cc and 152f 79cc. No hiperf parts available for them, except carbs and exhaust