My RPM is it to HI (8800RPM)

[vermi]

Hello,
I have my Kymco People 50S 4 strokes, with a 72cc kit, power camshaft, the original air filter, original CDI (modified), jet #92, polini variator, with rollers 7.6g and original exhaust.

My top speed is 46 mph (75 km\h) (on my dial), but I feel that I could going faster. I feel my engine retained at high speed.

At 46 mph (75 km\h) my digital RPM indicates the engine turns 8800 rpm!

But at this rpm, the motor comes down at 8500rpm and goes back up...


Is it possible is the CDI ?

What is the maximum RPM this engine can go ?

Do you think i can go faster or it's the maximum my motor give ?

[Peters]

Engine can rev very high

Does no good with stock exhaust though

Heavier rollers will bring the rpms down

[vermi]

Engine can rev very high

Does no good with stock exhaust though

Heavier rollers will bring the rpms down

I try  heavier rollers to see, i have 8.0g and 8.5g in stock.

[JJJoseph]

Your speed is almost exactly what I get with similar mods.  I can sometimes get to 9500rpm with a tailwind, or downhill,  but mostly 8500 max on the flat in still wind.  Max speed: about 75-80km/hr, depending on wind.

[MotoRandy123]

  You have to be very careful of over revving an engine. At some speed the rod will break.
There is usually a maximum acceleration the rod will handle. You changed the load on the
rod with a bigger piston so the max RPM will be less. On some motors the valves will float
limiting max RPM. That sounds like what you are experiencing
 
"At 46 mph (75 km\h) my digital RPM indicates the engine turns 8800 rpm!

But at this rpm, the motor comes down at 8500rpm and goes back up..."

  That being said the manufacturer usually builds in some cushion. I found out (by accident)
that my bike will rev 1000 - 1500 RPM's higher than it does in stock form...

  46 MPH is good for a 50! Most do 30 stock and 40 modified...