Harbor Freight Replacing Greyhounds

GoldenMotor.com
Hmmmmmm, lets do the math.

If the 79 CC is 52 X 38 MM then it is 80.7 CC.
If the 99 CC is 56 X 40 MM then it is 98.5 CC.

What if a 99 CC piston was stuffed into the 79 CC motor?

If the 79 CC is 56 X 38 MM then it is 93.6 CC [very interesting]

4 MM = .15748"

Just thinking outside the block [Box]

Have fun,
 

daRog

New Member
Apr 15, 2011
98
0
0
California
I've already seen these new engines at a local Harbor Freight in CA. No worries about them not being sold here.
You've seen the 99cc ones specifically? I haven't been to my local HF lately but as per their website, some of the Predator engines are CARB and others are not.
 

scotto-

Custom 4-Stroke Bike Builder
Jun 3, 2010
6,505
24
38
Ridin' inSane Diego, CA.
And the cheapest price so far for the 99cc........drumroll..................? Anyone, anyone?

Looks like I'll have to go to the new location (5mi. from home) on Friday and find out for myself. dance1 The two closest locations were both 20mi. away, one way......not nowdance1dance1dance1

dnut
 

worksmanFL

New Member
May 25, 2010
579
0
0
Palm Coast, FL
Hi All,

2-1/2 HP Horizontal OHV Gas Engine

Is this the engine you are referring to?
Does this have the same engine opening standard of 78mm?

What else would be required to install on a bicycle?
a. clutch?
b. ignition kill?
c. mounting bracket?
d. sprockets?

In the store,unless it was mislabeled I saw a price of $69.99, and with a 20% off coupon, that makes it $54.00.

Wow! Thats a deal!

I searched the topic but couldn't find anything.

Thanks guys!
 

silverbear

The Boy Who Never Grew Up
Jul 9, 2009
8,325
670
113
northeastern Minnesota
If it's blue then it is the old Greyhound and is 79cc. On sale because it is being discontinued, but still a **** of a deal and a good engine. I have two of them. Plenty for a bike. If it is black then it is the new Predator which is replacing it and is 99 cc. A little bigger footprint, but not much. The engine is the cheap part... making it into a motored bicycle is another story.
SB
 

worksmanFL

New Member
May 25, 2010
579
0
0
Palm Coast, FL
If it's blue then it is the old Greyhound and is 79cc. On sale because it is being discontinued, but still a **** of a deal and a good engine. I have two of them. Plenty for a bike. If it is black then it is the new Predator which is replacing it and is 99 cc. A little bigger footprint, but not much. The engine is the cheap part... making it into a motored bicycle is another story.
SB
OK, please tell me/us more?

:)
 
Hi worksmanFL,

You will need a drive system, exhaust system, motor mount, chain, throttle control [with kill button], throttle cable, gas tank, fuel line, fuel filter, rear wheel sprocket, and misc. bolts, nuts, washers, etc. Sadly the support equipment will cost far more than the motor, and will be hard to justify. I know of many that ended up spending far more than actually buying a complete 4-stroke kit, because parts are much cheaper when bought in large quantities.

The drive system can be fabricated in many different ways. You can use a jackshaft plate, bearings, a clutch on the motor crankshaft, a primary chain, sprockets, secondary chain etc. You can also purchase the Q-Matic drive already setup for the HF motor [often cheaper than buying all the parts and fabricating a "homemade" system]. Considering the clutch is wide, understand if located on the motor crankshaft the motor will be very wide, and will require some serious attention to the pedal arms clearing the motor.

If you use the Q-Matic drive, then the current available 4-stroke motor mount can be drilled to fit the motor, whereas other drive systems may require a custom mounting plate to aid in "off-setting" the motor to line up the rear chain path.

The exhaust port is in a poor location, and most route the pipe up and towards the rear, I personally don't care to have the hot pipe near the seat, therefore I suggest the pipe be routed to the front and then down under the motor.

Another issue to consider is the final over all drive ratios, since the motor is a low RPM motor, special attention must be paid to "get it right". You need a final ratio of 12 X 1 [11.5 X 1 to 12.5 X 1] to take advantage of the motor's torque, and overcome the narrow RPM range, if lower or higher it will require pedal assist, and or a very low top end speed. A few tried 9 X 1 and had to offer serious "man power" to get in motion, and found the motor struggling to climb small hills. Some tried 18 X 1 and found the motor wound out and the top speed under 20 MPH.


Hope this information is helpful, as we have a lot of experience with the HF motor, and several of our authorized dealers have been using the HF motor for several years, in fact I think Jim and Chris Davis in PA were some of the first to use the HF motor on a bike.

Currently we are using the HF motor to test our prototype 2-speed drive, and is a great candidate because of the narrow RPM range.

Have fun,
 
Hi worksmanFL,

Always consider adapting any motor to motorbike use will cost more than the motor selected. There are 4-stroke motors from the HF 79 CC to the HS 142 and prices range from slightly over $50.00 to just under $200.00 for various motors.

A good example is found in todays cars, as a youth, transmission repair was cheap, and rebuilding the motor was far more expensive, however today the transmission repair is far more costly than rebuilding the motor. This is true with motorbikes, the connecting parts [drive system] and mounting systems cost more than the motor, by far.

Overall the cost to build a motorbike is normally worth it because of the fun, and more importantly the never ending increasing fuel prices. Most 4-stroke motorbikes will pay for themselves in a short time, as many get above 150 MPG, and you don't have to purchase oil [it isn't free]and mix it.


Have fun,