market for 4stroke kits?

[Hollywood]

2 cents!!! I have both, a 99 Whizzer which was a real pain until Whizzer came out with a upper end upgrade ($400) which made it much more fun to ride.The Whizzer 4-stroke is a much more heavier engine and makes it harder to pedal when you only have pedal power.The 2-stroke Happy-Time engines which i have used to build over 10 bikes is a much lighter engine which makes it easyier in the pedal mode. As for performace i can make a 2-stroke with a little tweaking go as fast as a stock 4-stroke Whizzer.Happy-Times are way more cheaper to maintain.I have a new Grubee 4-stroke in the box and will start putting in a bike next week.At that time when i am done with it i will way in as to the 2-stroke kit verus the 4- stroke kit.For now APPLES AND ORANGES or what toys you like to play with.

 

[BSA]

The problem with 4 strokes is (in my opinion) that they are big and cube shaped. They are a pain to fit on the bicycle frame. Also I don't like the idea of belt drive. The chinese engines would be better if they had multispeed gearboxes. I originally was going to buy a villiers engine for my bike, but I went for the Chinese 60cc instead, which is excellent.

BSA

 

[Sianelle]

Someone mention Villiers?

 

[BSA]

yep, a villiers 1f engine. They were great on the old autocycles. The problem was that it went too expensive and I was not willing to take a chance on being able to mount it on the frame. Maybe a villiers for a future project as I have read the repairs manual about 20 times. I know the 1f like the back of my hand by now.

 

[atcspaul]

getting alot of mixed views. to make it simple will a 4 stoke 48cc keep up with a 2 stroke 48cc motor. some say one has more power then the other. i am getting real close to ordering a 4 stroke but don't want to get disapointed with a big loss of power.

 

[azbill]

the power is similar, the size is not
the 4 is much larger physically

 

[ulmo]

getting alot of mixed views. to make it simple will a 4 stoke 48cc keep up with a 2 stroke 48cc motor. some say one has more power then the other. i am getting real close to ordering a 4 stroke but don't want to get disapointed with a big loss of power.

Long story short.
It is important to understand difference between torque and power.
An internal combustion piston engine power comes from burnt fuel. The more fuel gets burnt during the given amount of time, the more power engine produces. Theoretically - the higher the engine is revving, the more power it produces.
Torq is force (force comes from pressure of burned fuel to piston head) multiplied by moment arm. Moment arm is half the stroke of piston. The longer the stroke, the bigger is torque and smaller power.
Why? Because if stroke is long, then piston has to move much faster at the same rpms and accelerating and decelerating piston and piston rod means losing power, the are also limits of acceleration moving parts can bare.

2 stroke engines have higher specific power, because they burn fuel at every crancshaft revolution, but they do not burn as effectively as 4 stroke engines. So it is fair to think that 2 stroke engine is about 1.5 times more powerful at the same rpm, than 4 stroke engine. They give more power, but not more torque.
It has nothing to do with the feeling of acceleration an engine gives to your bike, torque is what makes that feeling. As said, torque depends on the lenght of the stroke.
Hight torque and low power engines are installer, for example on cruisers, high power and lower torque engines are installed on supersport bikes.

 

[HoughMade]

getting alot of mixed views. to make it simple will a 4 stoke 48cc keep up with a 2 stroke 48cc motor. some say one has more power then the other. i am getting real close to ordering a 4 stroke but don't want to get disapointed with a big loss of power.

Show me a 48cc 2 stroke that will exceed 35 mph with my 220 lbs. on it. My 4 stroke Honda will...with power to spare...with a 56 tooth sprocket...and I have a 48 tooth just lying around.

 

[jtotton770]

The bottom line is If the only way was to have two rats in a cage running on a treadmill
hooked up to a chain I would still do it . And would probably feed them drugs to make them go faster too .

 

[Andrew735]

Im going to buy a 4-stroke just b/c i can stop anywhere and fill up. i dont know much about them so i was wondering if someone could tell me if this kit is a good one or if i should look somewhere else...

http://www.bicycle-engines.com/49cc-complete-powered-engine-p-156.html