3.5 HP small lawnmower engine

GoldenMotor.com
Sep 4, 2008
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to anyone interested you can check out my vertical shaft powered bikes at my space video vernons video channel or url retired tinkerer/my space. a great place to buy an engine is at small engine warehouse.com in indiana. bought a 6 hp take off with heavy flywheel for 75 bucks this winter. built another bike for my son with it using same system as shown on my space but with 2 3/4 in drive roller whee 35 mph plus!!!! we decided before he does any serious riding were going to upgrade the brakes !!!!!!! retired tinkerer
 

Egor

New Member
Jan 30, 2008
714
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Hurricane Utah
Dan it is easy to make up a drive for that vert engine. Just put a twist in the belt it works well. I think you are seeing the same thing I see when I look at those motors. LOL. If the two shafts are on the same plane it is easy, some of the mowers have a belt done that way to drive the wheels. There is an engine that also has an output shaft off the cam, they just extend the shaft through the cover and you get 2-1 reduction. Have fun, Dave

PS: I have a pile of vert engines just waiting for a project.
 

Dan

Staff
May 25, 2008
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Moosylvania
vernon, your vid still amazes me. The mounting looks like it will out live the motor, bike and us. Ya know, that would sell well. Just the mounting. Add your own mower engine, lol.
I know I would buy one.

Vernon's link


Thats a great thought about the belt, Dave. If run out aft and behind would look really cool and 1900's.

Know what you mean about how ya look at every motor and think "hmmm"

A some day project I have in mind is useing the concept of a ridding mower tranny. A neighbor of mine gave me his old ridding mower with a 8HP monster engine. The cool thing was it has a vertical shaft that spins a large round plate below the engine that looks like a potter's wheel that drives a smaller wheel that drives the mower and blades. Distance from the center to the out side or where the smaller driven wheel is, is how the speed of the output is regulated. Big, clumsy and works awesome! No good for a MB but would be an incredible trike rigged, surrey. Not going for speed or nimble, leaves a lot of wiggle room and with a variable speed tranny, could do some thing wild like steam drive. Just a fantasy, but would really enjoy making a DIY steam engine.
 
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RidingInVegas

New Member
Apr 28, 2009
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Las Vegas
Hi all, first post, love all the great concepts here!

Was wondering if anyone had tried using a shaft driven motorcycle's hub and drive shart with a lawnmower engine? I have a couple of ideas how it might work:

1) Modify the hub to fit the hub of the bicycle wheel and attach the drive shaft to the engine shaft. Would take a good deal of modification to the hubs, and a good solid frame, but seems possible.

2) Attache the hub to the engine shaft and crankcase, and attach a friction roller to the drive shaft spindle coming out of the hub. Less modification to the hubs, and can use mounting concepts from other friction/gravity driven designs.

Motorcycle drive shaft and hub assemlies can be bought off ebay for $35-$100, and proably could be found at the local junkyard as well. Of course brand new ones could be had if desired.

Anyone seen anything along these lines, and if not, am I crazy to think this could work?
 

Dan

Staff
May 25, 2008
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Moosylvania
Howdy RIV, welcome. Not crazy at all and sounds pretty cool. I had thought a shaft driven bicycle wheel would in theory work but dunno if it would hold up under engine speed and vibes. FairRacing found these. My thought was turn it 90 degs. so it is up with and connect to shafts via belt pulleys one being a centrifugal clutch. Belt would be less noisy then chain. Reduction would be kind of odd though as the driven wheel would have to be really big. But that would just add to the funky look.

Post lots of pics. It is a really cool idea and again, welcome.


Hunter S.Thompson's chosen epitaph suggests: It never got crazy enough for me.
 
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robin

Member
Nov 15, 2008
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Penticton British Columbia Canada
It wouldnt be that fast. You could run it off the rim if you wanted to see how it would work. You could set it up nicely if you put some time into the structure. Depending on the motor. there is a chance there is no throttle and if there isn't then it would an ALL on or off set up. I have actually put some decent thought into this idea before I just haven't decided start to spend the time on making it work.

and Lawn mowers can't run for a long period of time at much of an angle the oil and gas will find a way out...sometimes through the air filter and there is a big mess. So you are stuck with it being Vert.
but what if is a stroke it should !!.cptr.
 

RidingInVegas

New Member
Apr 28, 2009
2
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Las Vegas
Thanks for the encouragement, I will post pics and info if I can actually make this happen.

I love the idea of using a shaft drive bicycle to hook straight into an engine. However, I'm not considering turning the bicycle into a shaft drive, but rather keeping the bike intact on the chain/sprocket side, and adding the differential from a motorcycle's hub to the opposite side of the wheel. The drive shaft would then run straight up to a vertical shaft motor mounted behind the seat.

My other idea of a friction drive with the differential mounted under the vertical engine's crankcase seem overkill now that I've seen the videos in this thread, although it could be a simple way to add a shifting system to a friction drive.

If I can get this project off the ground, I'll start a new thread on it. Thanks again for the welcome and encouragement.

side note: quoting your post with a url caused my response to be spam blocked lol!
 

Egor

New Member
Jan 30, 2008
714
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Hurricane Utah
Vegas - I think Yamaha had a little MoPed that had a shaft drive. It would be fun to see if one could be found, and then get one of the little 2.5 hp engines from Harbor Freight for 99 bucks and then point it to the rear from out in front of the pedals. There are so many variations of a good idea. I never look at a bike the same way any more. I was riding my Whizzer around at work and saw a couple of cops on there bikes I stopped and told them that I could put a engine on there bikes and make them go 30 mph, they just laughed. I wonder what the department would have to say if they showed up with Happy Time Police bikes. LOL. Have fun, Dave
- Harbor Freight Tools - Quality Tools at the Lowest Prices 79.5cc four stroke 2.5hp
 

Cody Broken

New Member
Apr 19, 2009
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McCall, ID
ducatiluke, if you could post close-up photos of your engine and tech details I would be very grateful. Most everything I've read online says its a bad idea to run a vertical engine horizontal. I'd love to see how you did it.

I got a 3.5HP B&S lawn mower that is in good condish for $15. One possibility I found it to get a riding lawn mower trans axle.
 

ducatiluke

Member
Jan 20, 2009
39
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los angeles/ south australia
i find this forum's photo loading bs.
send me your email ill send pictures ect

iam member of motoredbikes also under ducatiluke

i modified the oiling system so that the engine can run with the crank horizontal
i used a oil dipper from horizontal shaft this is all that is required to convert the engine

it bolts directly to the con rod and splashed oil the engine running at this angle works perfectly i am a motorcycle , small engine , bicycle , mechanic that is i have been employed in these fields

after a year of riding i pulled the engine down and found no new weari think this engines are very well enginered to last after storage in winter and to be light weight and to be cheap to manufactor
honda motors are heavy and use roller bearings that rust up during long periods of non use
and are expensive to make


ducatiluke at hotmail .com
 
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