Lawnmower Engine Retrofit?

[arceeguy]

What about using the verticle shaft as a friction drive, running against the side of the rim rather than the top of the tire?

This guy is my hero! Check out the videos, he shows exactly how he got a vertical shaft engine to work on a motorized bike!

I'm guessing that the engine he used had a "heavy" flywheel, as most lawn mower engines have lightweight flywheels and they depend on the inertia of the blade to keep them running smoothly. If you pull the blade off of most lawn mowers, they will be difficult to start and will not idle even if you do get them running. Another hurdle is that they often use 7/8" shafts, where common pulleys and centrifugal clutches are designed for 5/8" or 3/4" shafts.

Shame that they are so difficult to adapt for bikes and go-karts because they are so darned plentiful. Passed by two mowers in the trash on the way to work. I bet that all they needed was a good carb cleaning to get them running again.

 

[Jax Rhapsody]

They arent hard to use for gokarts. You just need a riding mower axle or a front axle off a fwd push mower. I seen someone made a trike out of a ridin mower on craigslist. Just think of everything being turned 90 degrees and a tilted up axle.

 

[Large Filipino]

This guy is my hero! Check out the videos, he shows exactly how he got a vertical shaft engine to work on a motorized bike!....

WOW. That idler wheel on the other side. That's the secret,dawgs.
That's the secret.
Yea it probably has something of a flywheel.
But whatever because IT WORKS.
Thanks for that link "a"guy (uuh! Bad words!)

It's videos like these that show ANYTHINGS POSSIBLE.

All I need is a welder,some angle iron and a lawnmower engine and my trike is good to go for the front wheel.

 

[muddawg]

i knew somebody somewhere had to have done it
just too many around

mike

 

[grouchyolfart]

Man, I was just about to go out to clean up my old lawnmower to sell at a garage sale. We cancelled the garage sale so I'm going to spend the morning taking the thing apart so I only have the engine left. Hey, the engine's easier to store than the whole mower. I just know someone's going to come up with an affordable kit for these sometime soon.

 

[mslipac]

how would a guy set up the carb on those engines so you can idle it low and control the engine speed...all lawnmower i ever had only have one speed as you fire it up

 

[muddawg]

different applications will have different carbs
and many will interchange

mike

 

[imperfectionst]

Well, my old mower is 6.5 Hp, that'll get 'er done! I wonder how many cc's.

 

[arceeguy]

how would a guy set up the carb on those engines so you can idle it low and control the engine speed...all lawnmower i ever had only have one speed as you fire it up

Some mowers are equipped with a throttle. Usually the older and more expensive models. The ones with the fixed speed usually use the same carb minus the throttle control. The "throttle" on a mower doesn't connect directly to the throttle plate on the carb, it is connected to the governor and changes the governed speed. So when you pull the cable, the throttle plate goes WFO until the engine reaches its governed speed and then it closes. This could lead to some very jerky starts! Probably best to connect the throttle cable directly to the throttle plate and bypass the governor for smoother throttle control. The holes for the throttle stop screw (idle speed adjustment) are probably in the carb, but I've seen cases where you would need to drill/tap. Might be easier to find a carb from a mower with a speed control or possibly mount a small motorcycle carb which would have many more tuning options.

Well, my old mower is 6.5 Hp, that'll get 'er done! I wonder how many cc's.

A typical 3.5HP B&S side valve engine is 9 ci or roughly 148cc. Lawn mower power ratings are merely "opinions" if you ask me because the last time I looked, the "6.75" on the engine wasn't actual "horsepower" but some vague "gross torque" rating that probably can't be compared to another manufacturers engine. Surprised to see L-Head side valve engines still being produced with the ever tightening EPA and ridiculous CARB regulations.......

 

[graucho]

Well, my old mower is 6.5 Hp, that'll get 'er done! I wonder how many cc's.

All of my minichopper builds had 6.5 hp honda's installed. 198cc Not bicycle street legal.