HF 6.5 (200cc) motor on a bike?

[buck0]

Wow this is a great thread as I am building a 6.5hp hf engine. I will have to copy everything to Microsoft word so it's easier for me to find future references.

 

[oldtimer54]

There are two vibration issues we've had to deal with. The first is vibration upon clutch engagement. When we open the throttle from a dead stop and accelerate without pedaling, we would get an annoying vibration as the clutch is engaging. Once the clutch is fully engaged the vibration is gone.

There are a couple ways of dealing with this. You can pedal to get the bike moving which greatly reduces the vibration felt upon clutch engagement. You could modify the clutch to engage at a higher rpm. A typical MaxTorque clutch engages at about 1800 rpm. Changing the spring and/or shoes so the clutch will engage at a higher rpm will reduce the amount of vibration felt. And changing to a lower gear ratio greatly reduces the amount of vibration.

One of our 79cc bikes is geared 12.44:1 and the clutch is setup to engage at about 2400 rpm. The vibration upon clutch engagement is not bad and there is no vibration in the higher rpm range. This bike will climb very steep hills and it will do over 30mph.

The other vibration issue we've experienced is with the highly modified 6.5hp engine on one of our race bikes. This bike has a final gear ratio of 13.43:1. We do not experience the vibration when clutch engages on this bike like we do on the 79cc bike. This is due to the gear ratio and stall speed we are using on the clutch. However we do experience a lot of vibration in the higher rpm range. These engines vibrate. They are out of balance. Some are worse than others. The tolerances on these clone engines vary greatly sometimes so one engine will vibrate more than the other and one will outperform the other due to the varying tolerances.

We have customers who have taken their rotating assembly to a machine shop to have them balanced. This will eliminate much of the vibration the engines produce. The more mild engines don't vibrate as much and probably will not be an issue. I have a bike with a stock 6.5hp engine and the vibration is no problem. I have a couple engines producing about 15hp and they do vibrate.

Sorry for the long winded reply. There is a lot of information to share. Anyone can call me or email me to talk about these engines more.

This is great stuff. By the way I have a 53 tooth sproket on the rear. Did anyone look at the pics? As soon as I start my bike the cvt is engaged from idle. Idle is smooth ( does not rise or fall with lots of vibrations in the engine) but as soon as I give it any gas the bike bogs. Thanks

 

[oldtimer54]

Ok Ive found my jet drill bits. Going to drill out the main jet today. I will cut down the sleeve on the throttle cable today as well. Could you guys look over my pics and see if Ive made any glaring mistakes.

 

[culvercityclassic]

The bike looks good. Are you using that jack shaft set-up I see in the pictures?

I would also change out that quick release to the rear wheel and install a axel with some good nuts, the torque of this motor will pull that wheel right out of the drop-outs.


Keep us updated on this and how it runs.

 

[oldtimer54]

The bike looks good. Are you using that jack shaft set-up I see in the pictures?

I would also change out that quick release to the rear wheel and install a axel with some good nuts, the torque of this motor will pull that wheel right out of the drop-outs.


Keep us updated on this and how it runs.

I tought as much so I have a cromemoly axel lined up. I use the jack shaft for chain alinement.

 

[oldtimer54]

Ok Ive drilled out the jet to the next larger size and all of a sudden I have a engine that revs. Its still kind of boggy but once I can ride this thing Ill try drilling out the jet to the next larger size. Fixed the cable so I can ajust it. Now the CVT is engaged no matter how low the RPMs? Is there any advice as to how to ajust this tranny? Ive looked for instructions with the paper work but I cant find anything right now as everything is packed in storage. So how do I get this tranny to disengage at low RPMs?

 

[scotto-]

Ok Ive drilled out the jet to the next larger size and all of a sudden I have a engine that revs. Its still kind of boggy but once I can ride this thing Ill try drilling out the jet to the next larger size. Fixed the cable so I can ajust it. Now the CVT is engaged no matter how low the RPMs? Is there any advice as to how to ajust this tranny? Ive looked for instructions with the paper work but I cant find anything right now as everything is packed in storage. So how do I get this tranny to disengage at low RPMs?

I have that same tranny (less the extra j-shaft) and I would say start riding the bike as the belt should limber up a bit and lessen the constant engagement.

 

[oldtimer54]

Ok got it running and took a ride. Every thing seems great. Sure has lots of power and is nice and smooth. Going to check the plug for color and go from there. I love the sound of this motor. The frame, forks and disk brake realy work nice with this engine. Iam jazzed.

 

[kevinkrg6]

Ever get stopped by the coppers?

Ummmmm....it's 50cc lol.

 

[oldtimer54]

Where I rode my bike today:

 

[culvercityclassic]

Very nice pictures...looks like you are on top of the world.

How is that bike doing? Looks real good.

 

[oldtimer54]

Running great. Yesterday I took it all apart and stiffened up the jack shaft. The motor has sooo much torque that it was bending the metal the jack shafts bearing holder was brazed to. Iam adding a 100watt 12 volt generator to the bike and the angle iron I stiffened the jack staff with will make a great mount for it. Going to add a rack to the back of the bike to hold a regulator and a battery that I will be putting into a metal box. By the way those pics where taken at well over 10,000 feet.

 

[oldtimer54]

Hi guys my bike is running great but the rear brakes just don't cut it. I rode down a long hill and the rim got so hot from the friction that I blew the tube. Some how I need to install a disk brake on the rear. The disk on the front dosent quite do the job? Can you guys look at my pics and give me advice?

 

[chainmaker]

Widen the stays and go with a new 135 mm hub, if you went with a sportsman hub you can get the sprocket as well to fit, but it's a drum hub. Shimano makes a disc hub but you would need a top hat that allows a sprocket and a disc.

 

[PAracer]

Here's something that would be real cheap to try.

Stick a v-brake on the front fork (in addition to the disc). Run the cable to a dual pull lever so that you have front and rear brake on one lever, and the disc on the other.

 

[oldtimer54]

I have a 6 hole disk rear hub with a sprocket bolted to it. I was thinking of trying to use a my jackshaft for a brake but I have my generator pulley there?

 

[chainmaker]

Ok so you have a disc hub, it doesn't look like you have the brake mounts, I think Norm at venicemotorbikes has a rear brake adapter available for sale, and a top hat adapter from kingssalesandservice will allow a disc brake and your sprocket.

 

[oldtimer54]

I looked at the top hat adapter and its made for a 9 hole sprocket and turns it into a 6 hole? (or did miss something?) My sprocket has 6 holes. I just ordered this disk adapter: http://www.busettii.com/disc-brake-bracket-for-bikes-with-no-tabs-busettii-brackets.html
I might have to make some kind of spacer to get it to line up with the disk?

 

[dmb]

a hydro front works great call venice for one. and put a disk on the jackshaft, it doesent have to be on the end. warning they lock up easily so easy does it. any brake is better than none as you know.

 

[scotto-]

I just bought a HF 6.5 motor for $59.98 (at that price I just couldnt help myself lol) and I want to put it on a bike. But other then the indian 1911 thread I havent been able to fing anyone who is using this motor to motorize a bike? My grandfather rode one of those indian bikes in his day and filled my head with visions of tooling down the road on my own indian but this is as close to one as Ill ever get. Now just getting to town and back is ok but I need something a little more reliable then our HT motors. Then I could maybe go to the nearest city once in a while or maybe go exploring. Can I use this motor with a bike is there any info here that would get me up to speed? If I can use this motor how would my SBP heavy duty shift kit hold up to that kind of horse power? Do I need a tranny and if so where would I get one and what one should I get? Looks like Iam going to need some help with this project is there anyone here that has tried this and would be willing to give me any advice? Thanks guys.

Oh that's just crazy putting that big of an engine on a bicycle.....

Or is it???