go-kart w/ lawnmower engine, help!

[Figit090]

LOL.... awesome. yeah i want something with a roll bar, but i do like the speed...and i suppose i could achive it...maybe?

yikes. haha..

here's another plan, but its got a pretty high COG compared to the other idea, not horrible, but not the best either.

 

[Clip]

the second one is exactly what im wanting to do, but with a belt drive cent. clutch.

 

[Figit090]

why belt?

 

[Clip]

just cause, never thought about switching to a chain. is there any advantage of chain drive?

update: almost have a 200cc manual atv to take apart and use for the kart

 

[Figit090]

i suppose there isnt an advantage. i never liked the idea because it seemed like it would allow slippage or be weaker than a chain....but then again motorcycles use them, and they can even withstand the rubbing when disengaged on a lawn tractor so i dunno...

i just found this lawn tractor for free, but i'm not sure if its a good engine to use...i think it might only have 8hp and the whole thing is pretty old (60's) so even if i did get it running better it might be hard to find parts for and fully revamped its still only 8hp.... the only reason i'm considering it is the fact it's a horizontal shaft!

-___-_-_-_-_EDIT--_-_-_--

ok i found by searching online that its a 12hp (i believe) Sears Suburban lawn tractor... probably with a Tecumseh engine... unless there are different HP models, it should be 12.

now, with a centrifugal clutch, could i possibly get this thing to have nice torque to maybe rip it up a bit and also hit at least 30 mph? if the drivetrain is fine it has a 3 speed with reverse and high/low gearing.

 

[Clip]

thats exactly what youre lookin for, so h8r says. the 3 speed has bearings, and hell, youve already got a horizontal shaft. torque converters work wonders

 

[Toyota h8r]

thats exactly what youre lookin for, so h8r says. the 3 speed has bearings, and hell, youve already got a horizontal shaft. torque converters work wonders

Yes that is one of the old school rear ends that will take lots of abuse....that one might be a verticle shaft rear end......you'll have to look under tractor though. Some tractors used a horizontal shaft engine and a bunch of pulleys to effectively turn the belt verticle and go to the rear end.....make sense? Sounds like you guys have got the idea and are running with it..:evil2:

 

[Figit090]

Yes that is one of the old school rear ends that will take lots of abuse....that one might be a verticle shaft rear end......you'll have to look under tractor though. Some tractors used a horizontal shaft engine and a bunch of pulleys to effectively turn the belt verticle and go to the rear end.....make sense? Sounds like you guys have got the idea and are running with it..:evil2:

ok cool. well now i have to be a little bit more picky about this...i have one tractor in my yard that has parts like you described...a 3 speed (with blown/broken/misaligned reverse) tranny, a 5 speed tranny, and one running engine. 11hp vert. shaft Briggs.

this one i'm looking at picking up is a possibility but i dont know its condition other than that picture.

here's a pic of what i have. the one nearest is the 5 speed with no engine, the far one is a montgomery ward 11hp with the 3 speed and bad reverse.

at this point i'm not so sure what to use as far as a tranny, and tomorrow i'll call about the free lawn tractor with the 12 hp Tecumseh.

BTW...is a 12 hp Tecumseh from the 60's going to do good in this? it seems old and antiquated but...maybe not? what about parts availability? any ideas?
but yeah, here they are:

5 speed tranny:

3 speed tranny:

And here it is, the 11hp smoker!!!!!!!

i'm actually thinking back and she might run without smoke, i'm not sure. i tipped it sideways to work underneath and oil got in the carb..or something. but now what i think back i'm not sure how the hell that happened...maybe a crankcase breather?? i forgot and without having the engine in front of me that makes NO SENCE but it must be the case... either way, after a few laps around my yard i think it burnt out and might have been fine...but i'm not sure. time willd tell. i have to charge up the battery and see how it runs now. also, there is no throttle...its odd, and only has a weird choke/throttle so its hard to tell how it will react to throttle input. i'll have to power wash it and clean it up a bit to mess with it. but now that summer is here, I CAN!!!

let me know what you guys think!!:biglaugh: :naughty:

 

[Toyota h8r]

The 4th pic down is the very same rear end im using.....how is reverse bad? a simple tear down should reveal problem. Parts are a lil bit hard to find for the 3 speeds.....but if u can find tractor junkyards u will be set. I do have a "few parts" laying around here so guys if u need something ask and i can see what i have. Im gonna sell all my tractors, mowers and stuff minus race tractor....unless someone wants a very close to being done poject:evil2:. The "second version" has the brake petal, gas petal, and misc to hook up and thats it. Im using an 11hp briggs and the 3 speed rear end as of right now due to the 18hp starter dying. i blew the belt to due pulling wheelies wit the 18hp:evil2::evil2::evil2:. No centrifical clutch here.......i rigged an coventional cltuch setup so i can rev up...then slam it to wheelie or fly through mud.......

 

[Clip]

im thinking as long as the engine has been run a bit, it should be fine (even from the 60s).

 

[Figit090]

awesome, i'm not sure what's wrong with the gears...they ALL went down once, so i ripped it apart on my quest to learn more with mechanics, couldnt figure out what was wrong, re-assembled it, and discovered the forward gears worked. so maybe the shifter is out of whack...i vaguely remember there was a problem shifting...and you had to really mess with it to get it into gear....

so that 3 speed is durable and will handle lots of crap eh? how till a 11hp engine do in terms of speed, torque, and wheelies?

i cant get a hold of that owner of the 60s sears suburban. it looks like it could be pretty sweet (hi/low plus 3 gears and one more hp, and horizontal shaft) but his phone is off!! arrrghhhahgha.

thanks for the help so far guys.

hey toyota h8tr, you should REALLY post up pics of your projects/work, and anybody else if you haven't already or have pics!!

 

[Isphius]

first, the clutch is like an auto trans tq converter. it lets u idle w/o a petal. Hit gas and go.


P.S. bike gear setup wont last for one sec at best.
your talking 1hp(human) vs 14hp (mower engine) Get my idea?

The clutch is called a centrifugal clutch. I used to build racing gokarts for a local 5hp briggs leauge when i was 12-14. The clutches work great as long as you dont get oil on them. And there easy to "tune" using a drill. For later engagement, you just drill the same size hole in each weight. And they are self balancing, so if you mess up the holes it doesnt matter. And BTW, a human can produce 1hp, but a regular 150lb guy can make 400+ ft lbs of torque. So no its not power that will break the chain. the bike chain itself could hold up 1000 lbs if you wanted it to. (the weak link are those clip links they sell with chains, just get a chain tool instead) But with a motor it will stretch and stretch so much and then break. Its the hammering effect of a single piston that makes the chains wear. And the horizontal shaft engines and vertical shafts are identical, except for a few minor details. The oiling system will be fine, just make sure you put a lot of oil in it. all the horiz. engines have is a dipper on the bottom of the crank that splashes oil all over. the crank will splash the oil all over the place and lube everything if you turn the motor upright thou. And The carb just needs to be turned upright again, and that will be fine. You will also need to mount the gastank slightly higher than the carb. But other than that, It should be pretty easy to mount and hook up. If you ever get a new motor, my siggestion would be an OHV engine, or an OHC honda motor. They have plenty more high rpm power and they run much smoother. Im still waiting for someone to make a 4v engine! But the old side valve(L head, flat head) motors are all about putting along slow and making good torque. There ok for just having fun, but the ohv motors do run much better.

 

[Clueless]

I want a shifter cart....oh, I can't wait to see how this turns out.

 

[Figit090]

shifter cart? as in 70 mph on road 5 inch rims carts? cool idea but i want a full suspension beastie with a rollcage but i will be able to shift mine too

 

[Figit090]

by the way...i checked out my 11hp briggs again today. charged up the starter battery and took it for a spin, NO SMOKE!!! so its in good running condition, i just have to fix the carb because i think somebody removed the throttle and did something to the whole setup, there should be a choke but it seems to actuate the throttle and the throttle lever is GONE. sooo...yeah. i dunno.. but at least it runs well. i thought i'd have to rebuild it, at the very most i'll probably try to address the oil leak on the crankcase...but other than that, i'm good!

oh, and as for the the internal oiling design and problems tipping a vertically oriented engine upright for horizontal output...my engine has an oil filler...and a dipstick. sooo that's going to be a no-go. i'm sure it could be rigged up to fix that, but if i plan to use the tranny from this tractor, or most other lawn tractor trannys, i'm going to just keep the stock pulley/pully clutching system and get a shorter belt. the two objects really aren't all that high, and compared to a larger setup on a 18hp or so pre-built with a torque converter, i should end up with a lower center of gravity...every time i look at this engine its smaller. lol.... but anyway...

who knows a lot about these transmissions? i want to open mine up and see whats wrong with the reverse gear. hell i'm not even sure if its supposed to have oil in it or if i even filled it the last time i took it apart..... oops!! but yeah, if reverse is an option with my setup, i must have it, even if it means i have to track down a new tranny.

anybody got good ideas for CV shafts? maybe even suspension arms? it would ROCK if i could get some pre-fabbed suspension parts...just add the shocks and bolt it up.... i'd be so happy! because its going to be hell making sure the setup won't bind.

 

[speed]

I don't know about CV joints, but when I was building mine I got front A-arms from a place online.. i'm trying to remember the name. It was a farm store, but they had all sorts of homemade gokart shit- brakes, diffs, arms, steering, suspension, solid axles, pretty much everything. IMO, don't try and go with an IRS- the amount of fabrication is going to be pretty hefty. Go with a solid rear with a diff and call it good. Save yourself a LOT of trouble.

 

[Figit090]

ok. that sounds like a good idea... what about suspension? i'd like to have something if i have this much HP and speed... i dont want to be jostled so much my back hurts. i have a little 3.5 hp cart and when i go with any speed through the messy stuff it hurts my back. and no i'm not old. its f'ing ruff unless i air down the tires, and its still bad... (they're small though too so...maybe larger ones will help)

i thought independent because i didn't want the engine and tranny jostled around either. will it be fine to stick them both on a large swing arm section and just suspend the frame/seats on the suspension? i know prebuilt carts do this but somehow i just didnt like the idea of my engine and drivetrain bouncing around like that. but maybe it wont hurt anything....

i only figured if i could find some good CV shafts, i'd mount the tranny, and attach the CV's to the tranny's output shafts instead of affixing wheels. in your example i will still be affixing shafts but they will be solid and serve merely as an extention so i have a larger wheelbase.

plus with your idea i have less ground clearance, but i'm not building a supercart i suppose....

if you can find that site that would ROCK.... was the stuff well made and not too expensive? my idea on this project is cheap...if i have to learn how to weld good enough to make my own a-arms i will.

i have some automotive background and RC background so i know how things go together, its the welding skills that will be an issue....

i suppose i should first worry about whether or not i will be able to weld up a frame on my own/with dads help.

how much will steel tubing used for this application cost me?

gosh so many questions. sorry i should have waited for the rest until later but i dont want to forget anything and its' bedtime. ack. i'm impatient. sorry!!!

 

[speed]

K i gotta be honest, I'm a little drunk- and thats just too many words to actually read. I'll comment tomorrow.

 

[Figit090]

k thanks for waiting

when you do read it, also look at these plans and tell me what you think..

http://s24.photobucket.com/albums/c14/theo44/Sprint/

the one and main problem i see in this design is the obvious fact that the camber on front AND rear tires is going to be changing uncontrollably whenever the suspension moves.... problem? i dunno. hopefully someone with more experiance will chime in. personally i would rather have a dual A-arm setup to keep the wheels straight up, and allow only little changes in camber.

 

[speed]

Ohhh you're building a dirt/offroad kart. Mine was a street kart.

As for ground clearance, a solid axle won't sacrafice that much realistically, howevever if you're going to be going fast offroad, you really should go with IRS. If you do do a solid axle, yes you'd need to mount the motor/trans on a sway arm. If you do the sway arm, be sure that the engine is mounted both at the base and at the top. If it doesn't have a top mounting tab, you really should weld one on. If you do IRS you'll be fine mounting it in the chassis.

About the amount of tubing for the frame - since mine was a street kart, it didn't take as much as an offroad buggy will. However, I'd brace it considerably more than he did. Try going to a metal recycler place, or anywhere that might have left over tubing. The whole thing doesn't need to be the same thickness, (though do be careful when welding different thicknesses of metal together), but by finding scraps you can save a whole lot of money. Spend a full saturday practicing welding (I'm assuming you'll be using a MIG?), so that you can get the point that you get full penetration. don't worry about it looking pretty, you can always grind it down, the important thing is that the metal is properly fused. I picked up MIG welding in about 5-6 hours, shouldn't take you much longer than that. The trickiest part about frame building is getting both sides to match, and notching the bracing so that its snug.

As far as camber going, don't worry about it. It won't be at negative camber enough to really affect anything.

If i left anything out, please let me know. Its pretty slow at work so I'll have time to browse the web