Big Engine Bicycle 79cc 4-stroke

[macarollo]

I am thinking of using one of these for my next build.... remove the limiter of course!

What about mounting it on a rack above rear tire... using a jackshaft to connect the engine to the rear derailer?

It could be a good combination.... 6-7speed + 4 stroke engine!

 

[ZnsaneRyder]

Wow, forgot this thread was still here! LOL

Macarollo, my original plan when I bought my Staton wheel was to Rack-Mount this 2.5HP engine. It ended up being used on my brother's bicycle trailer instead! This little engine is quiet, lightweight, and get 135MPG, what more could you ask for? Also 38MPH top speed. Not super-strong acceleration, but plenty to move you, and a toolbox other cargo stuff as well.

I still plan on doing the rack mount with another 2.5HP engine in the near future. I plan to retire the 6.5 and use the little 79cc. It will be lighter, and most MBikes are "80cc" anyway, so a 79cc 4-stroke would be gas efficient and powerful.

 

[Rgvkid]

Hey Znsane, Its been awhile. I like the 2.5 setup. How does it do on the steep uphills?

I just received an HF coupon flyer in the mail for the 6.5 at $99 until April 13th. I don't have the money for another one right now, but what i do is call all the local HF's until i find one that is out of stock, then i get an IOU for the sale price and i can get it later on when i have the cash. They will still honor the price even if it is past the sale date.

 

[srdavo]

2.5hp HFT Greyhound-- --Rolling

Testing: so far, so good.... runs quiet.... plenty of POWer.

('cept for the rear wheel, with the broken spokes!!
To be fair.... I started with a wheel, that had at least 4000 happytime miles.)

My new wheel should be done today. Josh, my LBS guy has some fatty spokes... more later.



http://www.motoredbikes.com/showpost.php?p=193644&postcount=96

 

[ZnsaneRyder]

Testing: so far, so good.... runs quiet.... plenty of POWer.

('cept for the rear wheel, with the broken spokes!!
To be fair.... I started with a wheel, that had at least 4000 happytime miles.)

My new wheel should be done today. Josh, my LBS guy has some fatty spokes... more later.

View attachment 16522

http://www.motoredbikes.com/showpost.php?p=193644&postcount=96

WOW! That 2.5 got some power to break that wheel, even if it was previously used! I'm glad to see you are enjoying that 2.5 engine! It's starting to get more popular, and at least it's not 196cc, lol.

We were going to build my bro's trailer with a 6.5, but the trailer was too narrow for it to fit without modification, and the 2.5 fit better, and is easier to control because it's lighter and smaller.

How does that trike handle at speed with the 2.5? Are you able to go fast and keep it stable? I've really wanted to make one after seeing your AWESOME build!

 

[srdavo]

I doubt the engine had much to do with the wheel damage.... it's age & miles....coupled with the unusual stress of turning without leaning, prolly did it in.
I mostly ran straight roads, at speed. I did test my steering in a big gravel parking lot.....some swerving & some tight U-turns.... tight meaning... a 24' turning radius!!

I'll update more in my thread, when I get my new wheel & get some more miles on 'er.

As for the Little greyhound....I wish I had a couple more of them....I'd luv to build a 2-wheeler frame around one!!

 

[Nuttsy]

I've had one of these since last Oct./Nov. and have been running it every week to break it in so that when I do build something around it, she can just rip. Need to know tho, to disable the governer, is it just a matter of removing the spring or is there more to it than that?
Thanks
WC

 

[ky biker]

I have two of the Harbor Freight 2.5hp engines,one on a side pusher motor that I have been riding since last summer and been doing fine, the other I put on a trike and at about 200 miles the exaust valve spring keeper broke and let the spring come off it did not do any damage to the valve or piston. I went to ever small engine shop in the tristate and was unable to match it, finally had to order from harbor freight catalog store and will have to wait 6 to 8 weeks for delivery. I orderd 2 exaust and 2 intake keepers in case it ever happens again. I think this was a fluke and other than than the keeper breaking these seem to be very reliable engines.

 

[macarollo]

I've had one of these since last Oct./Nov. and have been running it every week to break it in so that when I do build something around it, she can just rip. Need to know tho, to disable the governer, is it just a matter of removing the spring or is there more to it than that?
Thanks
WC

If the engine is anything like the 196cc the governor is internal. You can either connect your throttle directly to the Carb and bypass the stock throttle return arm...

OR you can use the throttle return arm, but you will need to remove the governor, open up the engine and pull the governor gear off.... kind of tricky since it has a tiny retaining clip.

 

[Nuttsy]

Macarollo,
Thanks. That's the info I was looking for. I haven't had anything apart yet but it sounds like the same setup on both size engines. At least according to my blow up diagram. I was hoping I wouldn't have to go in and take that gear out.
WC