New 79cc build

headtrama said:
I have been riding this bike off and on now for a while. Here are my thoughts of the 79cc motor, it's a dog off the line but once it gets going it's not bad. The motor runs smooth with no vibration, I could probably do a few more things to this motor to make it work better but I'm replacing it with a 99cc.
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Andy, Great race videos. Hey, maybe I am missing something but I can't see any of your pictures at Photobucket. I really want to see that kick start. The main question I have since I have a 79cc build is how did you get rid of that initial roll vibration and clutch chatter? I replaced the spring in the clutch to start pulling at 3100 RPM but the clutch chatter/vibration is still there...Dan
 
Yeah I'm not using a shoe clutch, I am running a cheetah clutch and get no chatter at all. Are you talking about the picture where I said I'll just put a loop in the rope and make a kick start. If so I was just messing around. It's still a pull start.
 
The only problems I have are with what I found on the Internet. It says 3/4" bore drive with 3/16" keyway and my HF79cc is 5/8" drive.

Factory Set to engage at 4000 RPM. The HF79cc engine Maximum speed (rpm) is 3600 RPM with a Maximum Torque (ft. - lbs.) 3.5 ft. lbs. @ 2500 RPM, so I'm thinking this might not work in my case.

This racing clutch looks like what I need if it fit the engine.
 
Already disconnected the govenor. Can you get the 5/8th " sleeve from where you buy the clutch? Where do you guys get a decent price on that clutch?

If anyone is interested I built a charging box out of Radio Shack stuff for around $20 to $25 which will convert a Sturmey Archer dynamo AC to DC and charge 4 AA re-chargeable batteries for a 6 volt lighting system. It puts out .2 to .5 DC when I turn the wheel. Too cold to set up a multi-meter and see what the charge puts out at 40 MPH.

Dan
 
headtrama said:
You need to remove the Governor.
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Buying the Noram Cheetah Clutch should get rid of the clutch chatter vibration, right Mike and Headtrauma?

I guess I asked the wrong question about the Cheetah engaging at 4000 RPM when I quoted the HF79cc engine statistic being Factory Set to engage at 4000 RPM. The HF79cc engine Maximum speed (rpm) is 3600 RPM with a Maximum Torque (ft. - lbs.) 3.5 ft. lbs. @ 2500 RPM. After I disconnected the govenor it opened the engine up to a higher RPM. So ... Headtraums, do you still think that I need to physically remove the govenor from the engine?

99cc-Throt-Link_zps3ad4943d-1.gif


Dan
 
headtrama said:
You need to remove the Governor from the inside.
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Are you sure about this? My understanding was that the bigger 212 predator needed to be removed from the inside, but I recall a number of us simply disconnecting the governor from the outside on the smaller 79cc greyhound and 99cc predator engines. That's all I did on a 79cc I used for several years before selling it and have been using a 99 predator for a couple of years now with the governor simply disconnected. No problems at all and I don't recall hearing about someone blowing an engine or whatever by simply disconnecting the governor from the outside. Could you clarify this?
SB
 
SB......I'm curious about this as well. Hopefully someone will chime in. But, when I pick up my new one Friday I think I'm still going to remove it from the inside.
 
SilverBear,

Did you run the Noram Cheetah Clutch on your 79 and 99 to remove initial clutch chatter and vibration while you bike is picking up speed?

Dan
 
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