Harbor Freight Greyhound 79cc engine

[joker]

hey kilroy
have you rode it enough yet to compare it to the china motors ?
i am building a bobber bike and am planning on using a greyhound just out of pure curiosity.
obviously will have more torque
when i was a kid i had a mini bike that i rode the wheels off of and it had a sintrifical clutch so i think that is the route i will take
good lokin build

ride on

 

[KilroyCD]

Hi Joker, sorry for the late reply. I haven't ridden it since the rally at Cape Henlopen because it's been sitting over at my brother's (aka Fossil on this board) undergoing some modifications. I'll see it next at the Motorcycle Extravaganza at Allentown PA on he 12th/13th of this month, but I won't have a chance to ride it there.
At the rally I liked the grunt it exhibited, plus the vibration is greatly reduced over the 2-stroke China Girl engines. It shows good potential as a bike engine.
Two words of caution though. The stock muffler is at the top of the engine. If you take it off and use a flex-pipe exhaust (as we did), it too will exit upward. Be very careful about exhaust placement, as it can turn the bike into a real crotch-burner. Below is a photo that shows how we routed the exhaust.
The second word of caution is to make sure you use heavy spokes. I know of a guy who mounted one on his tadpole trike, and the torque twisted and broke the standard 14ga spokes on his drive wheel. We have heavy-duty rims with 12ga spokes on our build.

 

[joker]

hey kilroy
so making a custom exhaust is out of the question ?
i guess torque is what they are about.
do you have a transmission of some kind or jack shaft ?

 

[KilroyCD]

hey kilroy
so making a custom exhaust is out of the question ?
i guess torque is what they are about.
do you have a transmission of some kind or jack shaft ?

Actually, making a custom exhaust would probably be a very good choice. The transmission we are using is the EZM "Q-Matic", which employs a centrifugal clutch.

 

[denali]

ok, Iregistered on to the fourm, now what?

 

[Dan]

Howdy Denali, welcome. The spam thing got to be a major deal. So now it is an automatic thing to block links and such from unknown sources until ya post a few times. Really makes for a better place to hang out. Is nothing but a safety net sort of deal.

Glad to meet ya!

 

[Quenton Guenther]

Welcome denali,

Have fun,

 

[denali]

Thanks Quint, I have read this thred on the hf 2.5 engine along with many others for the past 2 weeks, spent hours reading. Which leads me to relate to you that some men learn by reading and those that learn by watching and then there are those that just keep peeing on the electric fence. Any way the local HF has the motor, 2.5 79cc on sale for $89.00 which I think I will pick up tomorrow. I want to get in touch with Kilroy, I sent him an e-mail which he should soon reply to. He is not that far from me and I want to talk to him about my project on parts and adice. He seem knowledgable on the tech stuff. Open ato all suggestions, thanks Pat

 

[azbill]

chris and his brother jim (fossil) are pretty cool guys,,,lots of good advice from them

 

[Dan]

chris and his brother jim (fossil) are pretty cool guys,,,lots of good advice from them

Big time. Great folks!

 

[denali]

Hello. I went to harbor frgt today and got the last 2.5 they had in the store. 89.00 on sale with an extra 20% off, so with that,tax and I bouh=ght the extended warranty, 20.00
That gives u 2 yrs return for new replacement. So I can blow the engine and get a new one free. I think a good deal. Now I need a clutch and what ever else. I want to use a friction drive. Going to put it on a Ross mt. bike. It already has heavy spokes and gas fork. My problem is how to mt a twist throttle since the bike already has 2 twist shifter grips, help!!! any suggestion, changes. This will be my first attempt at this bike motor thingy take care Pat

 

[denali]

Oh, the total out the door$97.50

 

[Dan]

Could use a thumb throttle. Huge motor for a friction drive. Might be a problem. I am sure some one has done it and can advise.

Post lots of pics

 

[Fossil]

Change the right hand twist shifter to a lever and make that twist handle the throttle. That's the way I would do it.

Jim

 

[Dan]

That's a great thunk. Cheaper too

 

[denali]

Fossil, that right hand shifter has no less than 7 positions. Would the lever to replace workthose 7 also? Dan I think you are right about size. I will try to hold that motor i place for center mt but dont think there will be enough room. Still kicking around options I want to change the handel bars to cruiser style, dont want to lean forward all the time, not that young anymore,lol. HF also has what they call a log carrier, looks to be pretty substantial, I think that could easily be adapted to a nice trailer.

 

[azbill]

I replaced the 7spd grip shifter on my Jaguar with a lever shifter, it is rarely used so it doesn't even have to be an 'index' shifter (locks/notches into the correct position)

 

[RusticoRay]

Denali,
I recently used a thumb throttle and moved everything to the left 1 1/2 inches. I use my first two fingers on the brake and have the throttle spun around and the last three fingers for throttle. I'm with Bill on the shifter not much use.
That HF is to big in my opinion for rack mount. The MT bike for a center mount would require some cutting and welding but I suppose anything is possible. If you could drum up a cantalevier frame it would fit with a little modification. Can't beat the price.

 

[denali]

Ok Gentlemen, I picked up a thump shifter today and will use that. But I think I will take your advice on the size of the engine too big for friction drive. Also a pain getting clutch for this engine. I am going to change direction a little and take it back to HF, and then look for the best friction drive kit, I want the leastamount of fabrication as possiable. I do want the best engine with the most torgue I can get. I live in a very hilly area. I weigh 160#s so thats a plus. I know some of you can fab just about anything but not me. I like diy up to a point. Thanks for all the advice and look for more since I am as green as you get when it comes to motor bikes. Pat

 

[RusticoRay]

Pat, Several venders have FD kits with motor or without.
I recently like christmas day put a BMP kit on a hybrid schwinn, just waiting for a gas tank BICYCLE ENGINE PARTS, MOTORIZED BICYCLE PARTS . Good option if you have a weedwacker motor or another motor with a 76mm clutch, price is right also. I went with the 1.25 roller. Also Results Page has the kits complete with motor. Not the greyhound 79cc but will get you around nicely.