NitroRunner

Hey guys, I am currently working on a 12hp craftsman lawnmower that I want to make fast. I have already changed the gearing on it and it runs about 25-30kmh. I was wondering If anyone had any ideas as to how to make it even faster. I am putting an electric turbocharger on it right now, I know it probably wont help that much but I am going to do it anyway because I have the parts. I might even put a bigger engine in it, but that wont be for a while. I am 15 so funds are limited. Il post pics tommorow. Thanks

TeamTFR

My Feedback: (45)

I wanna do the same thing with my lawnmower....sorta...lol. I want it to be faster, but I still have to be able to mow lawns with it.....post up some pix of yours..

The_Collector

You best devise some sort of way to regulate the speed of that blower. Too much forced induction on these engines will result in engine damage and will set you back big time.

What brand engine does it have? If it's a Briggs, you're lucky, if it's a Tecumseh...then it's a Tecumseh[:'(]. The guys that make these into racers usually put on smaller wheels front and back, take off the deck, and modify the frame and axle to bring it down. I'm not sure what they are doing with the rear. They are getting these things up to around 60 mph, so I wouldn't be suprised if they are pulling the transaxle and putting in a direct drive with a regular clutch, like a go cart. The best I could do with my one rider is 10 mph, thats with a Kohler 20 and the smallest possible engine pulley. It will do that in less than 2 seconds, but it is only 10. The gearing has most to do with the top speed, so engine mods will only get it up to top speed quicker.

Your setup is a good one to start with. You have a single cylinder, and if it's an older cast iron or aluminum/ cast flathead, even better. If it's an OHV, and it's running okay, don't even bother to crack open the valve cover.

People do alot of interesting things with these mills. There are aftermarket parts available to modify these things, and they can be made to be some pretty wild engines.

NitroRunner

Ya im tryin to make mine faster too... but I cant think of much else other than a bigger engine, Its night now and my flash isnt great on the camera so il take some tommorow. Yup its got a briggs with a cast iron block. Ive thought about modifying the back end for speed, but again im only 15, Il see what i can come up with though.

The_Collector

It's a pretty restricted type of vehicle. Unless you like to weld and be VERY creative, you are stuck at the speed the factory gave you. They put LOW ranges in these gearboxes. The only way to add more usable speed without hacking would be to change the engine pulley and swap out the transaxle to a known compatible one with more speeds. This mod is limited, however, because only a select number of machines are known for this. For example, the early 90's Murray I have with a 12 HP Briggs has a 5 speed with reverse. At that time, the same machine was available with a 4 speed, and some with a 6 speed. I could make mine a 6 speed by cutting another inch or so out of my shifter throw and installing the 6 speed unit. To go from the 4 to the 5, all that has to be done is install the 5 speed and paint a "5" on your center plate .

It's kindof a shame really. With these 20+ HP V-twins they are putting in lawntractors, you could easily cruise over your field at 40 mph . It's really a matter of safety, though. We would all be buying a seperate driver's license for riding mowers.

-Inverted-

See avatar....

The_Collector

Those little JD's are goofy. I would feel like less of a man to ride one of those. They might as well put the Playskol logo on the front instead. [sm=lol.gif]

-Inverted-

I just hooked it up with photoshop.

The_Collector

Not bad. Love the NOS.

-Inverted-

I added the nitrous system
matching shifter knob
sparco racing seat
Giovanni rims
mesh grill in the slots on the hood
eyelets on the lights

As a joke I put a ferrari emblem on the induct
brembo decal on the side
and made a license with my name on the front. Unfortunately I dont have the big picture anymore, the avatar is kinda hard to notice some of the details.

NitroRunner

I like the oldies, I have an 81 roper with a 18 horse onan, and a 76 white with a 10 horse briggs

The_Collector

If that White isn't too far gone, and if you are really into it, you can restore that thing and get some good money. YES, there is a market for vintage little tractors.

NitroRunner

Its in pretty good shape, il think about it

The_Collector

If I remember, I'll post pics my beast after I get home from work.

Diesel_Fuel_Only

I'm sure its been mentioned in here, but can't you swap the pulley that's on the engine shaft with the pully on top of the tranny? I should do that with mine... LOL. Its a V-Twin 20hp B&S, and already that thing'll move. Or maybe I'll just jack my neighbor's diesel 4-wheel-steering Kubota :P

The_Collector

Yes Diesel, that is a possiblity. It really depends on how it is set up though. I have seen some pulleys that are just welded on from the factory.[:'(]

NitroRunner

I have replaced the rear pulley and the main drive belt, the rear pulley is now much smaller, i can still go bigger on the front but its an really odd pully so il have to think of somthing creative. Im gonna try to get the turbo on tonight and then il take pics after its on

NitroRunner

Heres a pic of the turbo, im working on a mounting bracket il take a pic of that in a bit

Kemo

SOrry dude, ur a nerd, and I say that w/o meaning it as an insult. If you can make me that lawnmower in your avatar, i'll see what engine i can get you for an rc

NitroRunner

Well the turbo is bolted on now. My little bracket turned out very nicely, now im going to run some hose to the intake box and thatll wrap up this little project.

-Inverted-

What do you think I didn't make it?. It was just a little Photoshop fun when I used to "photochop" stock cars and customize them.

The_Collector

Hmmm, does that have the carb with the adjustable main jet?

NitroRunner

Not positive but i think so, whys that?

Diesel_Fuel_Only

Haha I like that little turbo... does it make any noise like a real one spooling up? I'm not being an idiot, I doubt it does, but if it did that would be cool.

The_Collector

You might have to mess around with the main jet to compensate for the turbo.

I came across a site dedicated to modifying riding mowers. It was a while ago, can't remember the name of it. It had some pictures of a single cylinder briggs, much like yours, that had a crank-driven supercharger with a pulley and belt. He fabricated a shroud for it and everything. It looked really cool. The pictures didn't show the manifold and carb too well, so I have no idea what he had for an intake. I think it runs on testosterone.