Harbor Freight 79 vs Honda 50 and HS50

[MotorbikeMike]

Hello all, there has recently been a lot of questions, comments, ideas, and stated ideologies about some of the small 4-stroke engines which are still very new to allot of owners of Motor Bicycles.

I have ridden the RS35, and it was a nice smooth underpowered engine for my taste. I own and ride HS-50 and Honda gxha50, and I can tell you that both of these engines perform VERY well, and far above the results I had with RS35.

However, most recently, there has been a bit of a buzz about HF's 79cc Greyhound 2.5 hp OHV. There have been statements made as to its performance as a superior Motor Bicycle engine, even though it is rather long, and actually pretty wide.

What I propose is a chance to run these bikes together, and see what the results may be. So, I am in Sacramento CA., and there must be many 4-stroke bike owners within an hour or two of here?

Stock engine, the only mods allowable are remove governor (if equipped), open the exhaust, and use any air cleaner you like. No disassembly, nor internal mods accepted, this is not to see if you, or your friends, likes to hop-up "stock" appearing engines.

26 inch wheels, bicycle of any "normal" type (i.e. no plastic recumbents with streamliner bodies)

ANY gear ratio you like, BUT no shifting, no CVT, no Nuvinci, just see what the engine will do, not what kind of transmission you might scare up.

Anyone who wants to play, 4 stroke stock engines, BUT especially with the HF is welcome! I stock a lot of parts, and if you have trouble with your build I am willing to help you, no labor, just whatever parts used.

One major problem area is exhaust on the HF and I have solution for that here.

I await your entries!

Mike

 

[Nuttsy]

Apples to Apples

Large Deal! Your V8 Muscle car can outrun my Cummins Turbo Diesel. Big whoop-D-freaking do! And my CTD can pull a house up a mountain! Ooooooh!
You are talking about two very different motors built for very different purposes.
People are gonna like what they like for what benefit it can provide for THEM! PERIOD! One engine is not superior or inferior to the other. Its just a matter of what one chooses for a given purpose. And what kind of half-assed challenge is it to say all things have to be equal? Again, would you put a Porshe engine in a Freightliner and expect it to turn in the times that the Porshe would. And vice versa?
I may be Nuttsy, but I'm not STUPID!

 

[HoughMade]

I guess my question would be- when one puts an engine on a bicycle....what relevance does a sports car to semi comparison have? Frankly, a few people pull a trailer, a few build trikes, but I would venture a semi-educated guess that 95% of MBers want to run around on a bike with 2 wheels and no trailer. Probably 60-70+% would like to cruise close to 30 or a bit over. Given that background, a Greyhound to Honda/HS comparison with like bikes makes a lot of sense...especially with varying claims about speed, on both sides, out there. You aren't interested? One more topic you don't have to read.

 

[Nuttsy]

You are missing the point. The relevance is the fact that the engines were designed for different tasks. Now if you want to do this "challenge" with the HS v the Honda, all else being equal, OK. Or if its a comparison of what two HF engines can do with setup 'A' and drive system 'B', OK. Keep it apples to apples. But to tie the hands of either engine and not let them pull to their best benefit, then it's not a comparrison at all since one can spin to 8K RPM and the other 4-ish. What kind of contest is that? If what I have read about the HF 79 and all it's 'grunt' is true, then such a 'contest' on a steep hill with a load wouldn't be fair either. How can anyone not see that?
H, when did you acquire the attitude? I probably won't follow this thread since the theory is flawed from the start, but who are you to tell others what they do and don't have to read? The new thread police?

 

[spunout]

I think it's a great idea, mike, regardless of any potential naysayers. you are comparing two completely different motors and thats exactly the point. edit: the results of one motor may appeal to one, while the other may have benefits that are more of what someone else will be looking for. apples to apples.
i'll keep watching this thread because i'm interested in the results. and thats great you're willing to help out with parts.

 

[Youngbird]

Count me in too. I just got a HF 79cc today for $71.00 and change, so Im looking at all the comparables I can. Go for it.

 

[Tinker1980]

One thing I like about the HF engine is you don't have to get really elaborate with your gear reduction. If you only have to deal with gentle rolling hills, you can gear the engine to run 30 MPH at 3600 RPM and it will pull me (200+ Lbs) along just fine. If you've got a six or seven speed spare bicycle wheel, one can use the axle and cassette from that wheel, and using a 48 tooth happy-time style gear on the back wheel with a 10 tooth centrifugal clutch, you've got all the gearing stuff you need - just have to assemble.

The engine starts very easily, even in this unusually cold winter (0 degrees F) that we're having. One pull at full choke and it starts; run the engine on half choke for a little while if it's very cold outside. (If the engine isn't warmed up, and you open the choke, it tends to stall out when given throttle.)

The only complaint I have with this engine is the small fuel tank, and the screen inside that small fuel tank. There is a filter screen for when you put gas in it, it catches all the bad stuff that might get poured in. It makes it hard to fill up at the gas station.

-Mark

 

[atombikes]

If you've got a six or seven speed spare bicycle wheel, one can use the axle and cassette from that wheel, and using a 48 tooth happy-time style gear on the back wheel with a 10 tooth centrifugal clutch, you've got all the gearing stuff you need - just have to assemble.

-Mark

Mark, I recently purchased one of these HF engines, and am planning a build. Thanks for your insight; it sounds like you have already built one? I don't follow what you mean in the quote above? Are you suggesting using the 6 or 7 speed freewheel as a mid-drive (jackshaft)?

I started a thread on my Harbor Freight build here:

http://www.motoredbikes.com/showthread.php?t=25019

Thanks, ED

 

[Tinker1980]

You've got it - I plan to use the 7 speed axle as a jackshaft. I haven't yet finished my build, I'm working on it as time (and money) allows.

-Mark

 

[snowbanana]

does the harbor freight engine even compare with Hondas as far as reliability?