My Top speed?

saolom

New Member
Oct 14, 2008
48
0
0
Australia
Hi all, Today I took my little 70cc skyhawk bike out for a ride and clocked 53km's! I tried to go faster but had no more guts. Is this the maximum it will go for a stock kit? The only modifications was the stock air filter with extra holes drilled 8 times. I was wondering what type of speed you can achieve with these little beautys. :ride:
 

thatsdax

Member
Feb 22, 2008
869
1
16
www.thatsdax.com
30-35 mph with a 26 inch wheel is good. Anything above 28mph is great. Yours is running great. If you want more speed, you can change out your rear sprocket for a smaller one. The best for speed is the 36T. The best for speed and climb is the 41T. It seems that the 41T is becoming a favorite for the little 2 strokes . It seems to be the magic number being that it reduces vibrations greatly and adds some speed while climb ability is still there as well. With the 41T you seem to get all three, lower vibration, increased speed, and still offers great climbing. With the 36T you get lower vibrations and speed is increased greatly, but climb ability is reduced greatly. The 36T is good for smaller hills but great for speed. I love the 36T for my 2 strokes and I love the 41T for the Titan 4 stroke since it does increase my speed and since it climbs good, it is easy on my auto clutch. since the 2 strokes do not have an auto clutch, the 36T is what I love for my 2 strokes. The 36T may be too fast for most riders.. But.. I love my speed !!! Enjoy the ride..
 
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saolom

New Member
Oct 14, 2008
48
0
0
Australia
That 36 teeth sprocket sound good! what will it cost to melbourne Australia? Wouldn't mind extra speed at all. thanx
 

Motormac

New Member
Sep 23, 2008
108
1
0
Ontario Canada
Hi all, Today I took my little 70cc skyhawk bike out for a ride and clocked 53km's! I tried to go faster but had no more guts. Is this the maximum it will go for a stock kit? The only modifications was the stock air filter with extra holes drilled 8 times. I was wondering what type of speed you can achieve with these little beautys. :ride:
You must have been going downhill to get 53 Kms hour?? I ride a 700c bike and am lucky to get 41. thats with an after market performance air filter.Are you running a regular 44 tooth sprocket now?
 

saolom

New Member
Oct 14, 2008
48
0
0
Australia
Yes I was going down hill. On a straight road I could only get 46km's. Yes only the standard 44 tooth right now but will upgrade. I was lucky I think to get a good clean Kit because I have been going full throttle now for days and still running very smooth.
 

Motormac

New Member
Sep 23, 2008
108
1
0
Ontario Canada
Yes you got a good engine thats putting out a lot of power, look after it and don,t run at full throttle all the time, find a nice cruising speed and stick to that unless you need a sudden burst of power.
 

saolom

New Member
Oct 14, 2008
48
0
0
Australia
I forgot to mention that before I change the gas and oil with BP 98octane mix with FUCHS sIlkolene Scoot 2 ( 2T semi synthetic ) I only got crusing speed of 40km's. With the New mix I could feel the power screaming smoothly!
 

Andyinchville1

Manufacturer/Dealer
Dec 26, 2007
502
1
18
Scottsville, VA
HI,

FWIW here is what a customer of mine who bought a 27T sprocket from me had to say:

Aloha again...
With the 27 sprocket, i have gone 41.8 mph on the flats and 45 mph on slightly downhill
roads. Both I had to face about a 15 mph head wind...and I easily cruise at 35mph.
So now I want to go 50mph. I'm thinking about one of your custom exhaust.
How much is it? Keep in that I'm in Hawaii. My bike is a 43centimeter 27
inch wheels 370 series trek racing bicycle, it's bottom of the version of
Lance Armstrong.

Have a great day
Rick-Hawaii

....I have sold a number of 27T sprockets to people on the flats...

Hope this helps.

Andrew
 

80ccspeedster

New Member
Jul 28, 2008
18
0
0
Aloha,

Achieving higher speed is doable with these 2 strock engines. But It took me a lot of tinkering to get to the sweet spot. Along with the type of bike i'm using, I drilled 16 holes into the stock carburator; replaced the plug wire with a 8.5mm performance pw(any type of pw will do); adjust the stock plug from .040 to .025 this produces more sparks; and juiced the gasoline with a shot of octane boost (four caps full). But One thing I am finding out that is very important is to find the right amount of oil and gas mixture. On that day I made those numbers, I poured more oil mixture than usual because I wasn't measuring it. My guess is that the extra lubrication helped the piston do it's thing, push my bike to incredible speeds. The oil ratio is between 16:1 to 32:1.

Rick - Hawaii
 

Venice Motor Bikes

Custom Builder / Dealer/Los Angeles
Mar 20, 2008
6,631
439
83
Los Angeles, CA.
Yeah, I found that a few times when I just dumped a lot of oil in the tank (way too much) & added gas, the bike ran very fast! But they were also on cold DRY mornings!
 

jasonh

New Member
Jun 23, 2008
1,590
0
0
37
Longmont, CO
16:1 is way more than you need. A lot of people use 24:1 or 32:1.

I'm wondering if the reason more oil helped is the fact that more oil = leaner air:fuel ratio. You might try running 24:1 or so and move the clip on the carb needle up a notch and see how that works out.
 

ibcnya

New Member
Oct 29, 2008
220
0
0
Concord NC
Aloha,

Achieving higher speed is doable with these 2 strock engines. But It took me a lot of tinkering to get to the sweet spot. Along with the type of bike i'm using, I drilled 16 holes into the stock carburator; replaced the plug wire with a 8.5mm performance pw(any type of pw will do); adjust the stock plug from .040 to .025 this produces more sparks;
Rick - Hawaii
How does reducing the pulg gap make it run better? I tried this with mine yesterday and it was really boggy at WOT until it picked up speed. Opened the gap back up and it pulls real nice off the bat. Its a NGK BTW.
 

jasonh

New Member
Jun 23, 2008
1,590
0
0
37
Longmont, CO
How does reducing the pulg gap make it run better? I tried this with mine yesterday and it was really boggy at WOT until it picked up speed. Opened the gap back up and it pulls real nice off the bat. Its a NGK BTW.
If your spark is too weak with a wider gap, closing it will help. if not, no need to. I believe you actually get a hotter spark with a wider gap.
 

xPosTech

The Old Master Motorized Bicycle Builder
Oct 23, 2008
209
0
0
SETexas
Yes Jason the wider the gap the hotter the spark. Since the coil has to build up a higher voltage to jump the wider gap, It will be a little hotter.

Also it will minutely affect timing. The longer the coil must build voltage, the later the spark will be. So, the wider the gap, the later the spark. We ain't talking long, though. :)

Ted
 

OSCAR383

New Member
Jul 22, 2008
243
0
0
36
WEST FRANKFORT, IL
HI,

FWIW here is what a customer of mine who bought a 27T sprocket from me had to say:

Aloha again...
With the 27 sprocket, i have gone 41.8 mph on the flats and 45 mph on slightly downhill
roads. Both I had to face about a 15 mph head wind...and I easily cruise at 35mph.
So now I want to go 50mph. I'm thinking about one of your custom exhaust.
How much is it? Keep in that I'm in Hawaii. My bike is a 43centimeter 27
inch wheels 370 series trek racing bicycle, it's bottom of the version of
Lance Armstrong.

Have a great day
Rick-Hawaii

....I have sold a number of 27T sprockets to people on the flats...

Hope this helps.

Andrew

i got one of the 27t sprockets on my kids bike and i can do 35 full throttle clocked by analog speedometer on bike and brother driving my truck next to me .
 

Bikeguy Joe

Godfather of Motorized Bicycles
Jan 8, 2008
11,843
237
63
up north now
The best way to increase your speed is to go on a diet. rotfl
FO'SHO'!

Speed is a funtion of horsepower. A 20" bike with a 27T will go about the same speed as a 26" bike with a 44T or a 40T or a 36T.

You can't infinitely "gear up" and expect to go faster and faster, it doesn't work that way.

Sooo...to increase top speed, low gross weight and small, streamlined frontal area are key.

Thanks for listening.
 

saolom

New Member
Oct 14, 2008
48
0
0
Australia
Overall results for a 66cc/80cc motor kit for me MAX out is 63km's! Cruzn speed on flats is 45km's + , thanks to the 36t racing sprocket! Made such a difference!. I will not go back to a 44t sprocket ever! Hope to achieve an extra 2-4km's once I've hooked the boost bottle up. ride3