PDA

View Full Version : Lawnmower engine


Nic
02-23-2007, 04:06 AM
Hey guys, I am a student at All saints college in perth, australia. We are currently working on a go kart. We have got hold of an 11hp Briggs and Stratton engine off an old MTV ride on lawnmower. Do any of you guys have any suggestions how we would go converting a vertical drive to horizontal. So far we have thought of a 'twisted' belt system, do you think that will work?

TIA,
Nic :)

robertdjung
02-23-2007, 12:44 PM
If you dream it enough, you can do it. Belts won't last as long, which will be a bummer, though. And you'll still need to figure out how to get the belt power onto the axle for the wheel power, if that makes sense.

maybe make some drawings and post 'em!

Nic
02-26-2007, 05:30 AM
Yeah ill think about it and hopefull come up with a sketch.
Also another idea I thought of is to have a box with two bevel gears in it, although I thought they might not stand up to all the high rpm's. What do you guys think.

TIA,
Nic

funky ole
02-26-2007, 06:48 PM
i used to have a book on building karts.there was a twisted belt idea in there.it used 2 belts,one twisted,the other was loose and had a idler pulley on the non power side of the belt.they used a jack shaft to go from engine and twist the belt.the second belt was set up loose,and you pushed a foot pedal to make the kart go.hope this helps.

jrjulien1
02-26-2007, 06:51 PM
i feel that there is only one good way to use a horizantal shaft engine and unfortunately no one sells a kit to do it anyways it is to use a case with bevel gears in it preferably sealed with some oil in it for lubrication but if thats not available just grease them regularly


hope this helps

robertdjung
02-26-2007, 09:11 PM
kit for what? frame + engine?

Nic
03-09-2007, 04:18 AM
Thanks guys for all ur help

robertdjung
03-09-2007, 11:55 AM
of course! stick around and let's dream up some more projects. have you made any progress?

my_mini_bike
03-09-2007, 03:52 PM
yep, bevel gears. you can get them of moped scooters, but they have to be shaft driven not chain of course

philip metzner
03-09-2007, 04:38 PM
you can use a rider transmission, but the trick is not to speed the rpm up on the trans, it will burn up. you could speed it up a little maybe. what you have to do is use a large sprocket on the transmission output, and a fairly small one on the axle or wheel. also remember most little lawnmower engines use a aluminum flywheel cause they rely on the weight of the blade to run smoothly. make sure you have a iron flywheel on there. the transmissions im talking about are mostly on small riders and are a box like thing bolted down behind the engine.--phil

kibble
03-13-2007, 09:01 PM
i used to have a book on building karts.there was a twisted belt idea in there.

Is this what you're talking about?

my_mini_bike
03-14-2007, 02:24 AM
good diagram but what about the plywood engine mount ???

kibble
03-14-2007, 11:05 AM
good diagram but what about the plywood engine mount ???


Yeah, I don't necessarily agree with the plywood mount but that came from a book called Midget "Motoring and Karting" from the 60's or 70's. It's a bit dated, but it's got a lot of good information on it though.

ryf
03-14-2007, 08:12 PM
I'm making mine with a 17 hp

heres a few motor area mockup shots, not fully welded, but more than enough for mockup. its under 50" wide which makes it legal in our local forestry service areas. keep in mind, most of these trannies are design for 20" tires to run at 6-8 mph. I'm going a little over 2 to 1 on my rear axle (25 tooth to 11 tooth) ad going up to23" inch tires.

keep in mind, these transaxles are also used for lawn mower racing, and are pushed beyond 35mph pretty reliably. my area is too hilly for a truely "fast" go kart, but torque and momentum is a definite need. I plan on down gearing the pulley's and opening up the governor from 2000 rpm to about 3000 rpm. I am planning to use a double pulley system from the motor to transaxle to reduce slipping and give me a better shot at having it work out well....

http://i129.photobucket.com/albums/p224/ryf_photos/Heymow/P1000744Small.jpg

http://i129.photobucket.com/albums/p224/ryf_photos/Heymow/P1000745Small.jpg

http://i129.photobucket.com/albums/p224/ryf_photos/Heymow/P1000743Small.jpg

I joined to post this so go easy on me.

kibble
03-14-2007, 08:18 PM
That looks like a pretty mean machine you've got going! Nice, nice!

Crabapple
03-17-2007, 12:24 AM
I love the seat, and the idea.
Just keep on building!

buzzwest
04-01-2007, 07:15 PM
hey that's really good work, because i have a 5hp verticle shaft engine and I was really woundering how i was going to make it work. I'll probably just use it on a little road contraption so the twisted belt would probably work fine.
-good luck to you-