Harbor Freight Greyhound 79cc engine

azbill · #31 (**permalink**) 10-20-2009, 11:20 PM

I know the changing the rear sprocket alone will make a big difference
I am waiting for a Q-matic, and have already changed my rear from a 50 to a 56 tooth
right now(with the 56), my gearing is approx 19:1 using a manual 'silent-drive' trans (2500+ miles

)
the news auto trans will be be 17.5-18:1
with the hills here, and pulling the girls/trailer,I am going to be working it very hard to see if it can be broken !!!
if it can, I will, and then we will make it better

xlite · #32 (**permalink**) 10-21-2009, 06:41 AM

Quote:

Originally Posted by Quenton Guenther

Hi xlite,

Have any pictures of the HF motor mounted on a bike? Sure would like to see how you fitted it into the frame. How did you route the exhaust?

Have fun,

The install was a half-fast experiment to see if there was any potential to that motor and compare it to a HS. I would never trust the fragile brackets for long trips (or even short ones for that matter) but was able to determine it had more power than the HS. Spent more time screwing with the governor than anything else. It was also my first venture into a shifter type setup and arranged similar to the Dax in-frame. Stock exhaust. Gave a new meaning to the phrase "hot pants".

I plan to do a more permanent job and will do a build log with photos like I did with the SBP pipe.

bandito · #33 (**permalink**) 10-21-2009, 09:24 AM

I notice on the specs for that motor it has a 5/8ths tapered shaft, the q-matic will work with that shaft? I couldnt find any where as to its weight, how much does it weigh?

Fossil · #34 (**permalink**) 10-21-2009, 09:28 PM

The spec sheet pictures an engine with a tapered shaft but in fact it is not tapered and the Q-Matic works just fine on this engine. The two that I have seen are not tapered. The only thing I needed to do to mount the drive was to drill 4 holes in the drive plate so I could clock the drive at a slight downward angle. This needed to be done so the drive would clear the cylinder that is at a slant instead of vertical like the HS or Honda engines and the exhaust manifold. I think the weight is close to 24lbs. Hope this helps.

Jim

Quote:

Originally Posted by bandito

I notice on the specs for that motor it has a 5/8ths tapered shaft, the q-matic will work with that shaft? I couldnt find any where as to its weight, how much does it weigh?

xlite · #35 (**permalink**) 10-22-2009, 06:36 AM

The HF shaft is compatible with standard bike motor kit clutches but the hole pattern is not and must be re-drilled.

omegaunderground · #36 (**permalink**) 10-22-2009, 07:12 AM

that motor looks sweet, I am gonna see if my local harbor freight store has one in stock to check out today

xlite · #37 (**permalink**) 10-22-2009, 09:25 AM

Quote:

Originally Posted by omegaunderground

that motor looks sweet, I am gonna see if my local harbor freight store has one in stock to check out today

They are on sale for $89.00 in latest flyer.

professor · #38 (**permalink**) 10-23-2009, 10:34 AM

I have been following this post, was at HF and they were sold out (and will have some more in after the sale is over), so if that happens to you- get a rain check from the store and they said they would honor the sale price.

professor · #39 (**permalink**) 10-30-2009, 08:18 PM

I just weighed the greyhound on my scale @ 20 # (no oil or gas). It is wide though,and fairly quiet. The throttle drag is easily adjustabe by backing off the tension nut that it pivots on.

RusticoRay · #40 (**permalink**) 11-05-2009, 08:04 AM

The HF motor has found a new home. It's going on this one's twin that I rode on tuesday 30.9 MPH on flat ground WOT. As mentioned before it has plenty of grunt and will climb at 20mph until it runs out of fuel.

Thats a rack mount, frame mount and pusher seems like with a little modification all are viable.