Old 14HP B&S engine

[Nagoshi]

Following my other post that got 0 replies. Decided to rethink my stuff.

Got an old Roper 14HP yard tractor with a 14HP B&S engine in it that I could salvage basically everything on it. It still works great. It's a 5-speed + reverse but 1st won't work anymore. Struggle upon start, but no problem once it's running, so Ill have to find a way to help him start during winter.

Is there anything good to do with that? Everything on the tractor is good, even the seats, frame and tires. Im not sure how the transmission is linked to the engine tho, if it's fixed on it or another piece.

So, do you think that cuold be salvageable and turn this into a small off-road gokart?

Another silly question - could I turn the PTO, which is normally used for the blades to cut the grass, into some kind of supercharger (following another guy's idea about supercharging his kart engine ^^)? I could turn it on when I want more power and turn it off when I dont need it... The same idea could be used for powering the two front drives if ever needed (stuck in snow or mud...) or anything else it could be used for!

Just found a picture that made me laugh... but that would be the kind of thing Id like to end up with... my hood is similar to that one, so all I would have to do is cut pieces to make them fit, and find a way to put a suspension on those four wheels. I would also use the frame and cut it as low as possible while the engine, and all components, still fits there.

 

[jr dragster T]

That thing already looks pretty racing-ish. The supercharger idea wont work. I dont think theres enough RPM to turn a blower fast enough. Plus it takes HP to make it and 14 hp isnt a whole lot to spin a blower in the first place.

 

[Nagoshi]

I was asking that... simply by checking if my engine would still be able to run at maximal speed without losing too much torque when I engage the blades, so I wa telling myself "if it can rotate such a system of straps and blades with no problem, I could surely make it fit a small fan and make it blow in the intake". Besides, if the PTO turns at a 500RPM speed, I could gear it at a 6:1 or 8:1, it'd have plenty of power to do so, but then I wonder if a fan running at 3000 or 4000RPM would be enough for that.

It's not like it's a blower designed for a car, but for such a small engine I told myself a forced intake setup could help... assuming it can bring more than what the engine would lose by making it work!

That picture was something randomly found on the net. But I like how low it sits, for a tractor that size. And since it's gonna be used for off-road use I dont know if it would be all right without any kind of suspensions. Plus, that one in the picture can do 50mph easily

 

[ryf]

hmm, I built a full on mini buggy off a verticle engine mower.. there are Racing groups that build racing mowers, but they tend to frown on back yard bashing. I missed the Ski cart thing, neat idea, the general rule is going faster requires better braking, the stock brakes on a mower are GARBAGE. so add a new gocart rotor and caliper to the axle so you don't end up in a tree or rolled over. you can get alot out of those mowers, the 14hp briggs has ALOT of racing parts for the engine to let it spin up higher, but they are ridiculously expensive. most racing mowers change the tranny side pulley to a smaller one, but you need a calculator and some time, because drastic pulley adjustments =drastic changes in speed (back to the brake thing). many people also recommend welding/bolting the front steering bar pivot, this keeps it from throwing weight left to right as much, and for high speeds, is HIGHLY recommended.

superchargers for small engines are normally made from 70's Chevy engine smog pumps, but the results are.... hard to confirm? but anything that increases flow into the intake is good, so even good scoop to make air flow positive to the filter instead of pulled through the filter would help a little. if your going to run a supercharger, I would not hook it to the PTO switch, as this would cause your ride to be rich when you have it off, or Lean when its on, either way isn't great and too lean could be bad bad.

 

[Jerryburger]

Jeez- I'd think your mower, stripped down to just what essential for Karts, and re-geared (with the 14hp) would be a handful enough? Most of the lawn tractors have a belt or two going from the PTO to the transaxle input. You swap the existing pulleys for ones that give you more of an over-driven ratio. A decent LawnTractor would be a fun project! A neighbor had one with a Kohler 7hp, that'd pull wheelies if you reved it up and dumped it into 3rd! (Slow, 15 mph wheelies, but it still got your attention if you were driving it!) If you want suspension, it'd almost be easier to transfer the guts to a proper kart frame than to try and modify the tractor..
My .02.

 

[ryf]

this is what I did with 17.5 hp, no supercharger, 23" tires, over 50 mph sustained on GPS. a mower seemed a little under built for getting airborn

lots of guys are making trail mowers now, that might be something to look to for more info. these are pics from after mockup, before testing.. so chains aren't on in pics, but I wasn't updating my build thread

 

[Jerryburger]

Clearly evidence you have some Mad Max in your blood! COOL!

Now- shave your head, get multiple piercings/tatts, drive out with your kart into Sunday traffic and lean out SCREAMING at people in the lane next to you!
Do it! DO it! DO IT!

 

[Nagoshi]

this is what I did with 17.5 hp, no supercharger, 23" tires, over 50 mph sustained on GPS. a mower seemed a little under built for getting airborn

lots of guys are making trail mowers now, that might be something to look to for more info. these are pics from after mockup, before testing.. so chains aren't on in pics, but I wasn't updating my build thread

WOW Thats something Id like to drive. Nice job there dude ^^ Seriusly, that's the kind of thing Id like to end up with... thanks for the pictures! If you dont mind Ill print them and use them to build something.

I dont exactly remember if it's a 14HP or a 12HP I have. And as I said previously, I know it's hooked to a 5-speed tranny but I have no idea at all of how it's all hooked up. If I could simply put a CVT or centrifugal clutch and use sprockets for ratios it'd be one hell of a ride. Also, Im not gonna start tuning the engine (cmon, it's like 25 years old! and I got no money lol)

I know I would have to find brakes somewhere... do you think car drum brakes would work if I use them with the wire? I guess I could search scrapyards for some kind of brakes to put there.

As for the suspension... I do know it's gonna be a hard time trying to manage something in there. Maybe I could find another frame and make something out of it. At least, by salvaging that mower, Ive got basic stuff to start something - steering, direction, probably the rear axle, the engine itself...

ryf, about the ski kart thing, i wanted to use a small 3-ski (downhill rocks!) and put a small engine in it and either put two small knobbed tires or a small strap and turn it into a small snowmobile. Actually, I may still end up doing somehting similar... it shouldn't cost too much ^^

 

[ryf]

on the ski thing, use a horizontal engine, it will require far less to do it with, and less weight on snow is better. you might try 1 ATV sand paddle tire, just a though, less equipment, less cost, etc.

I wasn't recommending a build like mine by any means, I kinda went whole hog on it. chain drive might be tough, chains on their side are hard to keep on if they stretch, belt might be a better match to your application. use a kevlar mower belt, advance auto sells them by diameter, so you should be able to get something, I'd use a spring loaded idler to take out the slack though, as they do stretch with use.

I would start with getting it going safely, on using axle brakes, if you are using a transmission (no axle built in) I used a car rotor from the front of a ford aspire a friend had junked, drums are much much harder to mount, but the cable operated for the e-brake would work if you can get it to mount/welded on. I'd try if its cheap enough! most of the racers spend about $150 on go cart/cable or hydraulic rigs, but only because car parts cost about the same and weigh 4x as much. I wanted car parts because they would last 100x as long, even if you landed on it.

 

[Nagoshi]

yeah for the ski think I was thinking about a weed whacker engine or a chainsaw one. Weed whacher wouldnt be powerful enough tho.

I dont have access to the whole mower right now, cause I live 1h30 car from my parent's home so Im gonna digg this up this week-end and snap pictures of the old tractor. Im gonna ask my father first if he's still planning to use it, since he's got a brand new John Deere 24HP ^^

I was thinking about going wired brakes instead of going with a cylinder... since I did not want to mess up everything. I might even try turning it street legal (if Quebec's gonna allow that, of course... gonna send the car insurance thingy an e-mail to know about that!), that thing could be fun driving in the city. Plus Ive got a set of winter tires my girlfriend had when she sold her '98 Accent, they're brand new... all they need is a set of rims. And they're slim 13inchers, so it'll reduce the weight (altho my old set of 205-50R15 Toyo Proxes4 would look great on your offroad mower on the street with my Neon mags ^^)

Im gonna try to find some cheap brakes I could use with a wire, too. If drum's too complicated then Ill screw the idea up... I dont want that project to take whole years!

Do you have an idea of what I would do with the tranny? I dont want to spend hundred in it, but I wanna go more than 10mph too... also, clutch or no (never tried shifting on the go with it since I have to hit the brake first) I dont mind, but a centrifugal or CVT clutch would be great (but probably bring the prices up alot, since I have to bring the vertical power to the horizontal in some kind of way. Do you have an idea on that?

 

[ryf]

I'd go either mower clutch setup (idler pulley is pring loaded, hooked to pedal, or prefer centrifugal, I went idler because a proper centrifugal clutch for a 17+ hp rig is pretty expensive.

if money was no object, I'd go with a Comet type/infinite clutch system, costs alot, but having 5 speeds that are really wide band would be like making your engine spin to 7000 rpm. since these also provide the clutch action.

I'd drop to a smaller pulley on the trans, pulley's are cheap, so I'd try a couple, if you don't want it to be a shifter, you're gonna be limited to about 20-30 mph, but on a mower, thats pretty quick considering there is no suspension.

there are LOTS of 80-90's ATV's that had cable brakes, so the choices are endless, I'd find an ATV junkyard if you can, they provided me with my whole front end suspension (frame,4 arms and shocks, spindles, hubs... etc) for under $100!

theres also band brakes, they are pretty short lived though, work great with cables, if you decide to run band brakes, buy spare bands when you buy them, and plan on replacing them. you might run to run them double because of vehicle weight though.

 

[Nagoshi]

Thanks on the tip. Do you think a centrifugal clutch for a 11HP would cost alot?

Crap, just checked and it's an 11HP. And it's either a Briggs or a Kohler... I just dont remember which one.

If I go for an idler pulley with a clutch pedal, and that I can find a way to remove the brake there's on that thing, is that possible? And is there a way to... modify all that trans cheaply so that it can supports much higher speeds?

Thanks on the ATV idea, I did not think about that. I may as well use the whole frame and build something up... If I can put a suspension system on my mower frame Ill go with the frame, of if I can, Ill go with a custom frame, and I could probaby start with an ATV one.

Would disk brakes from an ATV be strong enough for the use?

And here's a picture of the same mower than I have... except mine got no front tires right now, the side skirts with "11HP" written on them are stored away (they could make great side skirts for anything if they are reversed ^^), the hood and skirts are made in fiberglass and I dont know if the large rear part is in fiberglass too, cause there's no rust on those panels. Frame itself got little to no rust... Even if it would have some, it's not rotten so it's still perfecly salvageable.