mounting an EZM drive to a HF 79cc engine

GoldenMotor.com

azbill

Active Member
May 18, 2008
3,358
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Fountain Hills, Arizona
I know there has been a few members here that have mounted an EZM drive to a HF 79cc engine,,,
I also know the drive needs a different mount hole pattern and the drive needs to be angled down at the rear to clear engine parts,,,

my question is, does anyone have a template for this or any advice to do this easily ???

BTW, this is for weekend-fun (Sam), but will help others as well :)
here is a link to his thread :)
http://motorbicycling.com/f3/4-stroke-ezm-silentdrive-boardtrack-attempt-24035.html
 
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silverbear

The Boy Who Never Grew Up
Jul 9, 2009
8,325
670
113
northeastern Minnesota
Bill,
I wouldn't mind seeing that template either. I'm planning a Greyhound for a 51 Schwinn cantilever this winter. I think Jim Davis knows about this as much as anyone. Hopefully he will weigh in here with some help.
Hey Sam! How's your new school in California?
SB
 

Don P

Member
Sep 1, 2010
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0
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indiana
Hi all
if you got the owners manual that comes withe the engine.
it has a "2-9/16" (65mm) hole distance" it is square. with "m8 threads"
hope that helps
 

silverbear

The Boy Who Never Grew Up
Jul 9, 2009
8,325
670
113
northeastern Minnesota
Hi all
if you got the owners manual that comes withe the engine.
it has a "2-9/16" (65mm) hole distance" it is square. with "m8 threads"
hope that helps
I not only don't have the manual, I don't have the engine either. The local (hundred miles away) HF was sold out, so I have a rain check to cash in a couple of weeks from now. 2 9/16 from what, the corners of the engine base? What are the dimensions of the base?
SB
 

azbill

Active Member
May 18, 2008
3,358
5
38
63
Fountain Hills, Arizona
thanks Jim !!!

Scotto, if you want a pdf, let me know (pm me your e-mail) and I will forward it to you (I already forwarded it to Sam) ;)
 
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Hi Jim,

Please send the PDF to Scotto and myself. I need it to help others attach the Q-Matic to the HF motor.

I know you are using the adjustable front pulley, but don't know your final settings or which belt I sent.

I will be setting up a drive for the HF later [for a dealer] and will start with a 2.5" front pulley as a guide.

Have fun,
Quenton
 

Fossil

New Member
Mar 15, 2008
228
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Guthriesville Pa
I will be setting up a drive for the HF later [for a dealer] and will start with a 2.5" front pulley as a guide.

Have fun,
Quenton
I ended up with a diameter of 2.75" for my setup. Also a very large sprocket on the wheel. 62 tooth is what I am running.
I see Bill is distributing the file but if anyone else needs it, please let Bill or me know.

Jim
 
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Hi Jim,

"Ticking" is the term used to describe when the clutch first starts to enguage.

The ratio from the motor to the clutch must be different in order to start the process on a low RPM motor such as the HF 79 CC.

On your brother's bike the ratio is 2.70 X 1 in the primary, meaning the motor turns 2.7 times per clutch revolution. His motor idles approx at 2200, whereas most low RPM motors idle near the 1000 RPM range. On his motor at 2700 RPMs the clutch is turning 1000 or near the "ticking" speed. His system starts to connect about 500 RPMs above idle.

Your HF will need to turn 1865 RPMs to make the clutch spin at 1000 RPMs [near the "ticking" speed of the Q-Matic clutch by Max Torque]. Your system starts to connect about 800 RPMs above idle.

It is hard to notice either motor advancing the first 1000 RPMs above idle, and both motors work well with the Q-Matic.

Have fun,
 
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silverbear

The Boy Who Never Grew Up
Jul 9, 2009
8,325
670
113
northeastern Minnesota
If anyone has photos of the EZ tranny bolting up to the motor could you post them? Visuals are always good. Also, some of you have installed the HF with success. I would like to do a how to thread for installing the HF motor on a Schwinn cantilever frame, a good platform, common and has been done. (I'm thinking of your Corvette, Jim.) I just got my Greyhound motor yesterday and was thinking how nice it would be for me and even more so for someone with no prior experience building a motored bike to have a clear step by step description with photos of how to go about it. From the simplest stuff to the harder. I'm picturing something like a photo of the motor right out of the box. Getting familiar with the motor... what is what on it and what you are going to remove. How to remove the gas tank, the muffler. Adapting or making an engine mount specifically for that frame. How to hook up the throttle. How to attach the transmission. Even if someone was using a different transmission, it would be helpful to everyone using the HF motor. I kind of like that motor. The way it looks is OK (except for that air cleaner). My motor came to less than $82.00 out the door at HF. That's pretty compelling for a four stroke. Some of us like to fabricate and "build" our bikes even if it is on a tight budget and this motor mated to a good transmission can make a great bike. Let's do a how to. If I start one on my 51 Schwinn, will you guys contribute? I'll do the wrench work and take pictures as I go, but a group effort would draw on others' experience and would be a great help to other builders down the line. And photos of other mounts or ways of doing things would be good. And you dealers could then have a thread to point to for a customer of one of your transmissions as a reference. What do you say? Will you help?
I'd also appreciate a link or two for a source for the adjustable pulley you guys are talking about to make an automatic clutch work well with the HF motor. Where did you get yours and how much did it cost?
Once upon a time as a much younger man I was a teacher in the public school system, first teaching English, speech, theater and film making to secondary students. Later I was involved with something closer to my heart as an Indian advocate, tutor and director of Indian Education in our local school district, working with Native children. I guess I'm still a teacher at heart. I like sharing knowledge and there's nothing like it when you can help to empower someone else. These motored bikes do that, too. So lets help empower some new people. What do you think?
SB
 

silverbear

The Boy Who Never Grew Up
Jul 9, 2009
8,325
670
113
northeastern Minnesota
I just took a look at Sam's build thread and I see he is using the older Silent drive transmission. I now have a Q matic and love it, but I'm curious about how different the silent drive is from what is being sold now. I assume it was not an automatic. How is it different in terms of using it, performance. Is the low end torque different? Do you need to pedal before letting out the clutch? Is it still being made?
SB