Average speed of 2/stroke

[AussieSteve]

You think wrong. There is no such law in Australia, yeah.

Three engines from three vendors? Which three vendors?

I think that Grubee engines have a plate, because they're intended for the US market, but I haven't seen them on others unless, again, they're intended for the US market.
There is no capacity restriction on our engines, only the 200W power limit.

My engine has a four-character serial number, but that's all.

 

[210061741]

Ok
Here is the deal.

The 48 cc revs up faster cause the piston is smaller and weighs less. ( Fact )
Lighter piston = faster revs.

I think out of the box most of the engines will go 20 to 30 mph.
Not dependant on engine size.

Alot depends on the users ability to proper tune the carb.

The carb being a hair rich or a hair lean makes a big difference on the overall engine performance.

Too rich and it will 4 stroke and loose power and speed.
Too lean and you don't get enough fuel in the engine means it runs way hotter and the max speed is limited by the amount of fuel you can get in the engine.

I would spend a huge amount of time to get the carb right cause on a stock engine it will make the biggest difference.

The second largest contributing factor is the engines ability to breathe.
To pass the required volume of gasses through the area of the cylinder port in the time provided by the duration that the port stays open efficcently at the desired RPM.

Even with the best of porting configurations a cat exhaust or any exhaust with a small header that is restrictive will reduce the engines ability to breate.

That is where the Expansion Chamber comes into play and is the best upgrade to buy 1st.

#1 it allows the engine to breathe and #2 the sound waves cause suction and closing of the exhaust port which increases the pressure in the cylinder and produces more power.

SO IN A NUTSHELL THEN....the engines ability to breathe and the proper carburation are the 2 factors that determine the overall speed of the engine.

No matter what brand....There all the same except for the PK 80.

The PK80 has a longer stroke but a shorter connecting rod.
Also the shape of the combustion chamber and the piston produce higher than average compression which outputs more power.

I wont go into the con rod to stroke ratio stuff cause it is far too complex.


Bottom line..........Get the carb Perfect and put any and i mean any Expansion chamber on there

THE REAL DIFFERENCE IN SPEED FROM 1 STOCK KIT TO THE NEXT IS THE STATE OF THE CARB TUNE AND THE RESTRICTIVENESS OF THE EXHAUST.

I can make any engine as fast as the next.

I hope this was helpful.

 

[motorpsycho]

my engine came with a little yellow sticker stating the mfg. date, serial #, c.c.'s and some other misc. information.
That sticker was the first thing i took off.

 

[Crobo]

my engine came with a little yellow sticker stating the mfg. date, serial #, c.c.'s and some other misc. information.
That sticker was the first thing i took off.

me too.

" i got the engine off of a weedeater officer, i think its around 30cc"

 

[Hajuu]

That's good to know aussiesteve, cheers.

 

[AussieSteve]

What surprises me, Mike, is that in their haste to ban mopeds from the MB category a couple of years ago, they forgot to set a maximum speed and engine size for motorised bikes.

The poor moped riders are limited to 50kph and 50cc maximum and have to pay rego and hold a license for the privilege.
We're limited only to the posted speed limits and have no maximum capacity limitation. (Although the 200W limit caps that pretty nicely.)

 

[motorpsycho]

man i'm glad i live in the U.S.A. and in a town where i don't have to worry about all of this mumbo-jumbo!