New to forum. How to make a 48cc faster?

dthcore · Nov 12, 2013

Im sure this has been asked before and i dont mean to annoy anyone im new to the forum.

My friend is 6'1 And a pretty heavy dude an easy 250 ish pounds.

He has no license and is buying a 48cc motor installed in the bike. Its brand new i think ill post a picture of it.

My question is, since he is a big dude and weighs quite a bit. Wouldn't the bike accelerate slower and Not go as fast? And if so or if not. What can he do to modify it or upgrade it to accelerate and go faster?

Im a newb. Dude has no access to internet so im helping out and hoping you guys can help me out haha.

And im also considering buying one and have been for over a year now. Just haven't done it. It seems like a bad ass hobbie.

.shft.

2door · Nov 12, 2013

First let us welcome you to the forum. You've come to the right place for answers.

How fast is "faster"? What kind of speeds is your friend seeing now? 25 to 30 is about average. There are faster bikes but when you start approaching the 40mph mark you need to keep in mind it is a bicycle, not a motorcycle. Bearings, rims, brakes, frame integrity all play into the safety factor. In fact your friend needs to pay close attention to those fenders. They can be a real hazard if not reinforced properly.

As for increasing speed you can reduce the size/tooth count of the rear sprocket. Smaller will give you more top end but impact hill climbing and acceleration. Engine modifications range anywhere from mild to ridiculous. Replacing the stock kit muffler with an expansion chamber type of exhaust is one quick way to gain a few miles per hour but isn't going to make it keep up with traffic. Proper carburetor tuning, aftermarket cylinder heads, engine porting and balancing are also ways to squeeze a little more performance from that engine.
Oh, and the engine on the bike you pictured is probably a 66cc engine, sometimes referred to as an 80cc. The older 48s had a more rounded cylinder and head. That one is squared off indicating it is the larger displacement.

Tom

dthcore · Nov 12, 2013

2door said:
First let us welcome you to the forum. You've come to the right place for answers.

How fast is "faster"? What kind of speeds is your friend seeing now? 25 to 30 is about average. There are faster bikes but when you start approaching the 40mph mark you need to keep in mind it is a bicycle, not a motorcycle. Bearings, rims, brakes, frame integrity all play into the safety factor. In fact your friend needs to pay close attention to those fenders. They can be a real hazard if not reinforced properly.

As for increasing speed you can reduce the size/tooth count of the rear sprocket. Smaller will give you more top end but impact hill climbing and acceleration. Engine modifications range anywhere from mild to ridiculous. Replacing the stock kit muffler with an expansion chamber type of exhaust is one quick way to gain a few miles per hour but isn't going to make it keep up with traffic. Proper carburetor tuning, aftermarket cylinder heads, engine porting and balancing are also ways to squeeze a little more performance from that engine.
Oh, and the engine on the bike you pictured is probably a 66cc engine, sometimes referred to as an 80cc. The older 48s had a more rounded cylinder and head. That one is squared off indicating it is the larger displacement.

Tom

Thank you for the welcoming. Well he's not buying the bike anymore, you were right. It is a 66cc, the reason is he does not have a license and the 48 is the only one that is legal here in Arizona.

Well hes planning on having a cruising speed of 20-25 he does not want that to be his top speed because he wants the option of going faster but only if he has to and he doesn't want his engine kicking, spitting and screaming to keep that speed consistent haha. He's a heavy dude like I said.

But he is in a 150 dollar budget after he buys the kit. That money is only for making his kit do what he wants or atleast better then stock. Whether its a significant deference or just a small one.

dthcore · Nov 12, 2013

And any suggestions of places that sell 48cc kits for a good price? I will look at the sponsors but if you have any other suggestions I would appreciate it.

MotorBicycleRacing · Nov 12, 2013

dthcore said:
Thank you for the welcoming. Well he's not buying the bike anymore, you were right. It is a 66cc, the reason is he does not have a license and the 48 is the only one that is legal here in Arizona.

Well hes planning on having a cruising speed of 20-25 he does not want that to be his top speed because he wants the option of going faster but only if he has to and he doesn't want his engine kicking, spitting and screaming to keep that speed consistent haha. He's a heavy dude like I said.

But he is in a 150 dollar budget after he buys the kit. That money is only for making his kit do what he wants or atleast better then stock. Whether its a significant deference or just a small one.

The Arizona law only allows 48 cc or smaller but in certain areas they will
throw the book at you for going over 19.999 mph which is the speed limit
in the AZ law.

You will be treated as if you are riding without a drivers license on an
unregistered motorcycle which is big fines.

The stock 44 tooth sprocket goes about 30 mph so I wouldn't change it.

A 48 cc should cruise OK at 20 mph even with a 250 lb rider and not be
screaming with the 44 toother.
I know 300lb guys that do OK but on 66cc bikes because almost no one
uses 48 cc motors in California.

dthcore · Nov 13, 2013

MotorBicycleRacing said:
The Arizona law only allows 48 cc or smaller but in certain areas they will
throw the book at you for going over 19.999 mph which is the speed limit
in the AZ law.

You will be treated as if you are riding without a drivers license on an
unregistered motorcycle which is big fines.

The stock 44 tooth sprocket goes about 30 mph so I wouldn't change it.

A 48 cc should cruise OK at 20 mph even with a 250 lb rider and not be
screaming with the 44 toother.
I know 300lb guys that do OK but on 66cc bikes because almost no one
uses 48 cc motors in California.

We wish we could buy 68cc, well im jealous. Haha

We kind of live in the middle of now where. Kinda, there are not too many cops around and i dont think they would bother. If they do then wed get in trouble obviously.

But back to the question. With a 150-200 budget what can we do to go faster and make our motors more reliable and safer?

Also any recommendations on websites that supply 48cc. Ive seen the sponsors and other websites but im wondering who you guys would recommend.

.xx.

MotorBicycleRacing · Nov 13, 2013

dthcore said:
We wish we could buy 68cc, well im jealous. Haha

We kind of live in the middle of now where. Kinda, there are not too many cops around and i dont think they would bother. If they do then wed get in trouble obviously.

But back to the question. With a 150-200 budget what can we do to go faster and make our motors more reliable

The 48cc 2 stroke kits cost as much as the 66cc kits.

With an additional $200 budget you can afford to buy a 49cc Huasheng 4 stroke kit with a T belt transmission.

This will be stretching your budget but you will be better off in the long run.

PS: This advice to buy a 4 stroke kit is coming from a seller of the best 2 stroke motor on the market.

biknut · Nov 13, 2013

If you're not worried about going over 20 mph, then why worry about being over 49cc? No one will know what size the motor is anyway. It almost impossible to tell the difference from the outside.

dthcore · Nov 13, 2013

MotorBicycleRacing said:
The 48cc 2 stroke kits cost as much as the 66cc kits.

With an additional $200 budget you can afford to buy a 49cc Huasheng 4 stroke kit with a T belt transmission.

This will be stretching your budget but you will be better off in the long run.

PS: This advice to buy a 4 stroke kit is coming from a seller of the best 2 stroke motor on the market.

Alright I will look into it!!

thanks for the reply!

dthcore · Nov 13, 2013

biknut said:
If you're not worried about going over 20 mph, then why worry about being over 49cc? No one will know what size the motor is anyway. It almost impossible to tell the difference from the outside.

Well, I can't afford to get fined. If for what ever reason I'm going 25 or 30 and a cop pulled me over that would be worst than if I had the 49cc. That is if he knows its a 66. I'm just not too positive if I'm willing to take that chance.

MotorBicycleRacing · Nov 13, 2013

dthcore said:
Alright I will look into it!! thanks for the reply!

Be very careful that you get a 4 stroke Huasheng kit with a reliable gearbox.
There are a few variations but a lot of them although initially cheaper will cost you more in the long run and may not be upgradeable to a reliable gearbox.

Sidewinder Jerry · Nov 13, 2013

I'm going to assume you don't have many steep hills to contend with. That being the case a single gear drive would work just fine. However if you lived in an area like I do (Tennessee) where 30% grade hills are common then you'd need a shift kit.

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New to forum. How to make a 48cc faster?

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