Jenny's new engine.

[Bike_Builder]

This engine revs up really quickly and smoothly. I gain speed climbing 6% and better grades with my bike. Topping out at about 5600 rpm which equates to 50 km/hr with my gearing. Up a steep hill! She really zings!
Balancing the crank is not only easy but absolutely necessary if you want to ride for more than ten minutes before tightening all of the bolts again. lol
This port map seems to work well with my pipe. I designed the pipe for low-end power, and to carry that through the rpms. The eye-browed transfer ports help the fuel delivery throughout the rpm range. Pipe pressures control the flow better this way than with flat topped transfers.
I'm running a 21mm Tillotson fuel block, and a 23mm exhaust port.
The tight transfers make for snappy throttle response.

 

[TheGeneral1]

This engine revs up really quickly and smoothly. I gain speed climbing 6% and better grades with my bike. Topping out at about 5600 rpm which equates to 50 km/hr with my gearing. Up a steep hill! She really zings!
Balancing the crank is not only easy but absolutely necessary if you want to ride for more than ten minutes before tightening all of the bolts again. lol
This port map seems to work well with my pipe. I designed the pipe for low-end power, and to carry that through the rpms. The eye-browed transfer ports help the fuel delivery throughout the rpm range. Pipe pressures control the flow better this way than with flat topped transfers.
I'm running a 21mm Tillotson fuel block, and a 23mm exhaust port.
The tight transfers make for snappy throttle response.

This engine revs up really quickly and smoothly. I gain speed climbing 6% and better grades with my bike. Topping out at about 5600 rpm which equates to 50 km/hr with my gearing. Up a steep hill! She really zings!
Balancing the crank is not only easy but absolutely necessary if you want to ride for more than ten minutes before tightening all of the bolts again. lol
This port map seems to work well with my pipe. I designed the pipe for low-end power, and to carry that through the rpms. The eye-browed transfer ports help the fuel delivery throughout the rpm range. Pipe pressures control the flow better this way than with flat topped transfers.
I'm running a 21mm Tillotson fuel block, and a 23mm exhaust port.
The tight transfers make for snappy throttle response.

Looks like a Gruber Skyhawk??

 

[Bike_Builder]

It's a skyhawk Gt5a.

 

[TheGeneral1]

It's a skyhawk Gt5a.

Sweet I have built 3 bikes with the Skyhawk...My new bike is my 1st 4stroke and I love it just not good off the line but topping out it will go as far as I want with no protest at all from the engine..Plus u know don't have to mix oil n gas etc. centrifugal clutch takes getting used to but pullstart etc. I'm happy!!!

 

[Street Ryderz]

This engine revs up really quickly and smoothly. I gain speed climbing 6% and better grades with my bike. Topping out at about 5600 rpm which equates to 50 km/hr with my gearing.

Previously you said you use a 48t gear out back! So now 5600 rpm with a 48t on a 26" wheel is only 22 mph or 35 kph and usualy 5700 rpm is the sweet spot for a stock engine and if balence is an issue it's most apparent around 7700 rpm witch would have you at 50 kph with the 48t gear !

 

[Bike_Builder]

Sweet I have built 3 bikes with the Skyhawk...My new bike is my 1st 4stroke and I love it just not good off the line but topping out it will go as far as I want with no protest at all from the engine..Plus u know don't have to mix oil n gas etc. centrifugal clutch takes getting used to but pullstart etc. I'm happy!!!

I love the little Honda clone!! We have a daily runner with one. Very few problems in 2 years! They are great! Nice build on that one, I love the color.

 

[Bike_Builder]

Previously you said you use a 48t gear out back! So now 5600 rpm with a 48t on a 26" wheel is only 22 mph or 35 kph and usualy 5700 rpm is the sweet spot for a stock engine and if balence is an issue it's most apparent around 7700 rpm witch would have you at 50 kph with the 48t gear !

I don't have a tach. on the bike. I know cars aren't going much faster than me up Columbia St., it's a steep one. 40-45 is hard for some cars on it. The engine is balanced for a range between 5000 and 8000 some, on a slight incline or flat she rolls right out to about 8000. Maybe I'm pulling the hill at 6000+.
I'm still lining the pipe up correctly. I move it a bit and gain a bit. I have to use the dyno next week to fine tune the placement. I had it hit really hard last year with the twin carbs on it. The old engine was the same, just had a hollower case. The tuning is changing all the time too. Those dyno numbers are certainly not the highest possible. I just threw it on off the street. No tuning or test runs. I'll dial it in this weekend and max this carb on the pipe once it is lined up correctly. Without being lined up right these numbers make me happy.
I'm keeping up with traffic in a city that has as steep of hills as San-Francisco.