RPM Range? Claimed HP and torque? Dyno runs?


Local time
11:38 AM
Mar 20, 2008
So what RPM range are these motors designed for? Has anyone done a port map of one? Has anyone thrown those numbers into a calculator? Or used something like the 2 stroke handbook to design a pipe?

So, what's the claimed numbers on the 48cc? 60cc? 80cc motors?
I believe the 48cc is 1.6 horse and the 80cc is around 3 hp. They say they peak a little higher. I have used both engines and they are not terribly impressive as far as engines go but they are actually designed for bicycles and are resonably priced.I started with a 48cc kit and peaked at 28mph and now have a fairly modified 80cc and have peaked at 38mph.
So there is a diffrence between the 50cc and 80cc engine, i thought i read somewhere they are the same engine.
they most likely are, just with different pistons and barrels.

so who can talk to the RPM ranges they're designed for?
I use a section of a mile long main road to get a rough idea on the engine's strength ( those aware of the section in Adelaide, it's the section between Main North and Bridge Roads, going up the hill starting at Gepps Cross).
The 50cc will strugle a bit, the 70cc won't strugle as much.
During the heat wave we just had, the 50cc got hot, but it was new then and not fully runnin, helps if you pedal and not strain a new engine, any engine for that matter.

I have switched fuels from 92 Octane to 95, may cost a bit more, but found I get better MPG with the 95.
When the engine is fully runnnin I'll try 98 Octane fuel and see how it goes.
Yeah I've had both engines. The (80) cc engine seems a little more torquey and seems a little better overall. Can't say it's twice they power as advertised. These engine run a 6 to 1 compression ratio which is totally lame. I don't have a tach hooked up but I'd say it starts to struggle about 5-6000 rpm. Which again is lame for an engine this size. A good two stroke this size should easily hit 10,000 rpm but you get what you pay for and thank uncle sam for the chinese import ban on 2 cycles. There are other engines out there and I'd be intersted in what works. Most engines I look at in the 80cc range put out 8-9hp which is like 3 times the power of these engines.Maybe someday I'll do some more experimenting but for now I'm happy just to be up and running fairly well. So far I've meessed with intakes,carbs,exhaust, gas/oil mixes,intake resonators and even nitrous oxide but the improvements hav'nt really been worth the time or money.
feelin, the trick, is to read up, and follow the math. That's why I asked what I did to start this off. :) go read the 2 stroke tuners handbook, or any of the many 2 stroke books out there. These motors could easily make 5-15hp depending on displacement, it just depends on how far you're willing to go with the dremmel. :)
Going to take alot more than a dremel. I'm sure nero could enlighten me with all his knowledge. You tune one of these to 15hp and I'll send you a thousand bucks for it, sound fair??
15hp...for how many seconds?!!?
This engines couldn't handle...the clutch couldn't, the gears couldn't, the head bolts couldn't, the crank couldn't...
So I don't know what part could.
maybe 6hp or so tops.