Built an absolute screamer

[nickaloadien]

So I been building these motorized bikes for some time now and had this engine kit laying around in parts in my garage for months. Decided to go out and buy a cheap bicycle and throw it together took a couple hours. (First time I did this it took me nearly 1 week!)

Every one of these I’ve built with the standard 66cc china motor and NT carb + 26 inch wheels 44 T sprocket has done about 45km/h to 60km/h. I was expecting this one to do about 35/40km max as I didn’t really mod s**t on it. But WOAH I was ripping down the street doing nearly 85km/h and I weigh 220lbs! I wasn’t even full throttle as well.

Is this a fluke engine or what cause man I didn’t expect that. One thing I did do was port the cylinder intake and exhaust it’s also a G4 open transfer cylinder. Gonna check the durations and see what kinda numbers I got running on this. Also I got the squish down to like .7mm which is important. Oh also I just remembered I either advanced or retarded the timing a little I can’t remember. I guess I did do some mods now that I realize it lol. I use 94 Octane ethanol free and 40:1 ratio

 

[GW's Motorized]

Those are some great numbers for a CG. It's probably a combination of the light modifications and the light fra.e of your bike. Have you chopped the tube out of the mugfler?

 

[cloakedvillain]

Those are some great numbers for a CG. It's probably a combination of the light modifications and the light fra.e of your bike. Have you chopped the tube out of the mugfler?

Don't do that, china dolls are too loud to begin with.

 

[Whitewill1412]

What kind of porting did you do?

 

[nickaloadien]

Those are some great numbers for a CG. It's probably a combination of the light modifications and the light fra.e of your bike. Have you chopped the tube out of the mugfler?

nope I did not remove the muffler baffle.

 

[nickaloadien]

What kind of porting did you do?

I can’t remember what I did i’ll check the numbers and get back

 

[Sidewinder Jerry]

So I been building these motorized bikes for some time now and had this engine kit laying around in parts in my garage for months. Decided to go out and buy a cheap bicycle and throw it together took a couple hours. (First time I did this it took me nearly 1 week!)

Every one of these I’ve built with the standard 66cc china motor and NT carb + 26 inch wheels 44 T sprocket has done about 45km/h to 60km/h. I was expecting this one to do about 35/40km max as I didn’t really mod s**t on it. But WOAH I was ripping down the street doing nearly 85km/h and I weigh 220lbs! I wasn’t even full throttle as well.

Is this a fluke engine or what cause man I didn’t expect that. One thing I did do was port the cylinder intake and exhaust it’s also a G4 open transfer cylinder. Gonna check the durations and see what kinda numbers I got running on this. Also I got the squish down to like .7mm which is important. Oh also I just remembered I either advanced or retarded the timing a little I can’t remember. I guess I did do some mods now that I realize it lol. I use 94 Octane ethanol free and 40:1 ratio

I've done 50 mph (80 kph) on my 4 stroke 33cc RS35. Oh I live in the mountains and was going down hill.

At 85 kph on a level road using 26" wheels with a 10\44, your minimal modified engine would have to be turning 12,318 rpm. All of this from an engine you were only expecting 5000-6000 rpm at best. Because in the past the best you were able to get (I'm assuming with engine mods on 26" tires using a 10\44) was around 8700 rpm.

 

[DAMIEN1307]

Because in the past the best you were able to get (I'm assuming with engine mods on 26" tires using a 10\44) was around 8700 rpm.

With the exception of the new Phantom 85s with no mods, they are capable of spinning out to at least 9000 to 10000 RPMs by design and because they are using a chainsaw, one piece, cylinder system along with the 52mm windowed piston and reed valve.

 

[Sidewinder Jerry]

With the exception of the new Phantom 85s with no mods, they are capable of spinning out to at leasdt 9000 to 10000 RPMs by design and because they are using a chainsaw ,one piece, cylinder system along with the 52mm windowed piston and reed valve.

Which puts the P85 doing around 69 kph (42 mph) on 26" tires using a 10\44. When the so called super speeds are claimed; math can verify or deny them.

 

[DAMIEN1307]

spinning out to at least 9000

@ImpulseRocket crunched some numbers for me when I hit 51 MPH and still had plenty of throttle left to go before I chickened out...lol
He told me that I was at approx 9100 RPM and corroborated that they are indeed capable of these higher RPM ranges which I was quite surprised to hear...lol.