Speed Build

Hi everyone i am new to this forum but started a build about a month ago. iv been watchin a ton of youtube videos and learning how to do this stuff and i just realized that most of the peoples videos iv been subscribed to are on this formum like arild365, CSAkid, Fearlessfront and many others. so here is what im workin with.

craftsman lt1000 (around 2001 i think)
18.5 hp briggs intek ohv v-twin
pretty decent tires
new belt
new pulleys
hand throttle
i have a buddy who races karts so im trying to score some brakes from him
6 speed transaxle

My plan for this is to end up with a go cart type thing while staying safe

So far iv only been doing the easy stuff because i have no welder but in the next week im bringing it up to my school shop so i will have a abundance of fancy tools and a welder. when i first got this mower i striped everything off and i had some problems with the carb that are fixed now. the engine runs great. My plan is to end up with around 30 mile an hour. i kow with the engine and pulley ratio i am using now it would easly go around 50mph and theres no way i want to go that fast so i dont plan on usin 5th or 6th gears. This is mainly for around my neiborhood and in the fields near my house not for any major off roading. the closest thing to off roading near me is the tree in my front yard... lol but i have a few large open fields that are near me and therew always kept mowed.

few more things i want to add to build:
1 in square tubing throughout entire frame to stiffin it up like a rock
metal arm rest next to seat to help keep me in
bike pegs to also help me stay in welded on by feet

heres what iv got
(figured out pics)


heres the beast of a engine. i had had some problems with it in the beginning. I completely disassembled the carb many time and cleaned it. there is a anitbackfire fuel solenoid thing in it that wasnt opening when i started it because i took out all the old wiring. once i learned that i hear you can take it out and just replace it with a bolt. that is not the case for this engine turn out it wont run without it. so i just cut the plunger that stopped fuel flow and put it back in. looking back on that i should have just rewired it. also got new fuel filter, new oil filter. cleaned the tank and all the fuel lines, and changed the oil. should be running great now.

( when i got the engine runnin i kind ran into the hood that was on the ground. as you can see in the top picture) my bad... lol:)

ok so heres all the stuff iv gotten done so far


had to move the clutch because it would hit the larger pulley that i put on the engine




had to put in a idler pulley


heres the new engine pulley its around a 6.8 inch


heres the 3 inch pulley that is on the trans axle

heres the throttle that i dont yet have hooked up to the engine because i need to order a longer brake cable

Alright so thats all the small stuff iv done so far the major stuff will come when i get it to the shop. i have not yet tested my clutch setup or even riddin it at all since put in the new drivline setup. im going to wait till i have it up on jack stand to test the clutch and stuff.

Now heres where i need some help. any advice or ideas are greatly appreciated. i want to get the center of gravity as low as possible so it doesn't flip. iv got the front plans figured out but still need some advice on getting lower in the back.

heres the stock front axle. i plan on cutting notches in the frame and lowering it. i am also going to cut the spindles off and fab up a v shape front axle like the one in the picture below to end up with about 4 inches of ground clearance in the front.

this is how i am going to make the front axle

alright now for the rear. this is where i need some help





so as you can see theres about a 2or 3 inch gap from seat to body and about 4 inches from body to frame i figure if i can make the seat sit directly on the body and the body directly on the frame i can lose around 7 inches wich will help alot. Right now there are 20 inch tires on it( witch are huge) i want to find around 10-12 inch tires for the rear so i can lose around another 5 inches. i want to lower as much as possible so please give all your advice. and any advice on any of the build will be apreciated. i am open for ideas.


Thanks... Kerry

hey man direct steer! you definately want it, ive almost killed my self multiple times from leaving the steering alone and going 40mph with it. also if no plans for upgraded brakes atleast use the stock ones and maintain them. its better to have some stopping power than now, ive rearended friends and hit stuff alot of the times because of no breakes, and believe me it doesnt feal good

also i know you want it low as posibly but if i was you id 15's or 16's your not gonna get the speed your looking for with 11's or 12's on the back, plus with the 15 or 16 it would still be low to the ground. and with the front axle you have, ive seen guys just flip the axle upside down instead of building a new on but it loweres it alot

oh yea i definetley had plans for brakes. im trying to get some hydraulic kart brakes form my friend.

i have a pulley that looks just like the one you have on your tranny, my belt ate through it and now i can stick my fingers through it. i dont know if it was just that pulley or if its all the ones like that

hmmm... well i hope it doesn't eat my belt. lol i ordered it for acme mower sports http://acmemowersports.com/index.html so i dont think it will. i guess we will have to see though

here are some pictures of the other side

redzz02 wrote:

also i know you want it low as posibly but if i was you id 15's or 16's your not gonna get the speed your looking for with 11's or 12's on the back, plus with the 15 or 16 it would still be low to the ground. and with the front axle you have, ive seen guys just flip the axle upside down instead of building a new on but it loweres it alot

10-12's was just a guess. ill probably end up goin with around a 15 inch. it just depends on what i can find. and my orignal plan was just to flip it but then i realized with it upside down the entire weight of the tractor is resting on those little c clips that hold the frond spindles on. so that would not be safe.

plus i figure i can widen the front axle by a few inches to make it event more stable

iv been reading through some builds and it looks like im trying to do the opposite of what everyone else is trying. lol everyone else wants big tires and it lifted way up and i want smaller ones and my mower as close to ground as possible. haha:) ha its a shame i had to tear down such a new mower to. i got it for free and i never mowed the grass once(i dont even think there was anything wrong with it)

I have the need for speed as well- after a couple ' failed' builds- im making safer stuff right off the bat.

Right now my mod is a 91MTD - plans are for a 18.5HP opposed twin, lowering, new lowered spindles , 6 speed shift on the fly setup, Ill haveta do an upgraded brake setup tho.

I started it as a 'low cost what i have around ' build- only thing into it is the original cost of the tractor- $25.

I bolted the front axle in to the top of the chassis ( left spindles stock - for now) - all i did for the back was use the stock 8" rims and mounted lower profile tires on em- i bolted the fenders and seat to the frame- which drastically improved a lower seating position/better handling- i had initally tried to see what a stock variable pulley setup, 6" motor pulley, 4" trans pulley and a 14.5HP OHV motor would get me - actually not alot- its barely faster then it was stock .

I had a murray with the 18.5 twin , 6" motor and 3 1/2" trans pulley to a stock 6 speed murray shift on the go trans- it ran me up to over 40mph ( it was scarey fast ) but was way to unstable for those speeds being nearly stock.

I have a spare 6 speed trans thats going in the MTD - hoping to gain some more speed that way by ditching the stock transaxle and variable pulley.


In your case- id definitly drop the seat/fenders- you should try the shorter profile tire trick first. I had to use tubes in mine to seat the beads, and keep em on the rims.

Flipping the front axle over would work- youd need to swap the spindles side for side tho- might be better off with the custom lowered front axle and either aftermarket or custom spindles. Id say definitly to make a direct steer setup- stock craftsman steering is definitly not the way to go- itll have a ton of slop.

Im custom building a set of spindles from 3/4" bolts, theyll be reinforced - mine will be in the center of the stock axle ( thatll be reinforced as well).

Id run some sort of bering hubs or wheels in front- thatll get less resistance from the front wheels- definitly pin or bolt the front/rear wheels on.

The transmission- has the original grease been taken out? Id suggest that- otherwise itll toast it - i broke several pinion teeth off on my first craftsman mod - effectively ending its run as a mod. If it uses oil, id drain it and run heavy duty gear oil, even some lucas oil in it- if its grease- add zerks .

Its cool youre planning the build out to be a safer ride- not just slapped together hap hazzardly.

dangeroustoys56 thanks for all the input. I was wondering how you did the shift on the fly setup? i have not yet switch the oil in the transaxle but it is definetley in the plans. With my build i am trying to be as low cost as possible seeing as how im 16 with no job. lol but i still want it to be as safe as possible. i want to have fun riding it not bieng scared of fliping or wrecking the whole time.

heres a list of what iv actually payed for


-6.8 inch front pulley $18 plus shipping
-fuel filter $2-3 plus shipping
-oil filter $3-4
-3 inch rear pulley $8.50 plus shipping
-1/4 inch keystock $2.50
-penzoil 10 w30 $3-4
-gas $3 a gallon
-champion park plugs $3 each
-96 inch belt around $20

heres a vid of the engine runnin without muffler.its runnin fine then but right after this i started havin some old problems again. i killed it and then when i tried to restart it it didnt want to start. it finally started but it was running real ruf. i tried to give it a little gas and it died instantly. seemed to be flooding cuz i could see a puddle of gad building up in the air intake and when i killed it gas was coming out of the exaust. anyone no whats wrong? it was running fine like 2 seconds before

Alright so it looks like im gonna gonna have to take the carb apart... again. but no big deal. heres some pics with the body peices off. they werent even bolted on before they were just on for picture taking purposes.




Now heres where im worried about fliping the spindels



ok so theres the top of the spindels it might be covered in grease but theres is a non load bearing c clip holding the spindel there. all the wieght is on a weld at the bottem of the spindel. If i flip it over all of the tractors weight will be sitting on that c clip and i dont think that will hold.

i havent done the swap yet- since before Christmas havent had any time to tinker - i took a whole shift on the fly setup off my parts 94 murray - it worked awsome on my 94 mod murray - the stock setup actually engages the clutch ever so slightly when shifting gears - im hoping i can make it work correctly on the MTD . If i cant, then ill run a straight rear axle, and either attempt to make my own right angle gear box out of an old lawntractor transmission or use my peerless 700 trans .

I have like 3 mod builds- 2 of which im working on- my MTD- a 80's MTD wizard into a 'go kart' , and a future wheelhorse/MTD rat rod build . Im also partially working on a 80's agway for light duty offroading- id like to get the agway and wizard together actually first- so can ride around over at my nephews place out in the sticks.


I swapped my MTD spindles around - i have my tie rod in front of the axle now , when i lowered the axle it wouldnt fit under the frame - had to use a spindle off another MTD that had the pitman arm on left side ( some MTDs have the pitman arm on either the left or right side ) so i could run the tie rod in front. you might benefit more from building your own spindles and locking the front axle solid. When i build the new spindles for the MTD - itll sit a whole lot lower.

My wizard im building super low right off the bat- custom spindles, straight rear axle, 5HP honda horizontal shaft, go kart clutch, 6" wheels, bering front hubs - i figure itll be about 4-5" off the ground - im building it super strong for phase 2 - addition of a twin cylender horizontal shaft ( when i get one)- itll just be something to mess around with once its built.


Just lowering the front end and shorter profile rear tires will bring the stance down - lowering the seating will also add to stability- my MTD handles tons better sitting lower - feel like im riding a 'big wheel trike' when i was a kid - i can really push it in the corners nicely.

yeah i havent had much time to tinker either with the rain and cold but im tryin to get work done when i can. oh the shift on the go is something of anoother tractor? i was hoping it was something simple that i could build. lol once i get this thing into the shop next week all the major work will begin.

im hoping to find another tractor to use for donor parts. i dont think ill be lucky enuf to find a bigger engine but thats cool cuz this one is plenty big

alright so ealer today i started having carb problems so i tore it down down and also fixed some things iv been needing to fix anyway



engine shroud off. not so pretty like that... lol pretty rust free exept for the flywheel. i sanded some of the rust on the side of the flywheel to get a better spark


got the carb off. heres where it sits with the throttle and gov. assy


heres the carb. it a twin barrel niki



k so what had happend was the pin holding the float on had slid almost all the way out and it was jammed causing it to flood like crazy


here it is dissasembeld


ok so what i did to fix it was get 2 pret thick paper clips and bent the ends over so there is no way it can slide out again




Alright so i took the time i had it apart to fix a few things. Last time i took the carb apart i forgot to put the seal(think it might be called a gasket?) for the air intake back on so i put that on. then i cleaned the carb out jus for good measures, figured it couldn't hurt. the old linkage for the throttle was slipping off so i replaced that with 2 paperclips. defnitley wont come off now. i also saw some dirt in the feul tanks so i cleaned that out along with some dirt that was on the air intake. also moved the throttle return spring to a better location. ill probably put another one on in the spot i used to have just to be safe.

after all that i put the carb back on and fired her up it gave one more big spurt of gas out the exhaust then... OH MY GOD WHAT A NOISE... it was beautiful. lol thats the best it has ever sounded. my neighbor would be pissed if he heard my lawn mower bieng twice as loud as his 900 cc sport bike that he spends hours a day tuning in his driveway haha:)

heres a vid but i doubt it will do it any justice. my ears were ringing when i went in side. its definitely better sounding than the first vid



and a good thing is i got my pulley alignment right because its runnin smooth... took me about an hour with a laser to align them.

i figured id mock up a design for the structure bracing and see what yall think. The the black is the original tractor the blue is the engine and the red is what i plan to add. i just gotta find some square tubing.



let me know what yall think and where i should add some extra support cuz yall have some firsthand knowledge on theses sorta thing.

Thanks

I forgot to mention you might want to add a 'snap back throttle' - use a foot pedal or hand throttle on the steering wheel- i had a hand throttle on the murray- i didnt like it- my MTD has a foot throttle.

On craftsmans- the weakest part is the front of the chassis where the motor mounts- if you have access to a welder - id weld the front part of the chassis to the back and reinforce it inside - most racers use small square tubing on the inside of the chassis ( when flipped over ) at the top of the chassis - something like this:




It also shows the clutch and direct steering setup.

To get it real low, youd need a jack shaft to raise the trans further up the chassis or switch to a different drive setup - can only do so much with a stock setup.

On my future Wheelhorse/ MTD rat rod - i plan on making it super low, and super fast - im mounting a set of 8" golf kart wheels on the fully modded chassis- hoping i can get my 20HP onan twin horizontlal going for it or a suitable replacement.

So do you think 1 inch square tubing would be alright? after seeing all this stuff about direct steering i really want it. i just hope i can figure it out. and if you look at some of my pics on the first page you can see the hand throttle and ill probably end up with multiple return springs. i wish i could do a jack shaft but i don't think i can afford it . but i plan on taking as much of the top side of the back. right now i figure i can atlesat drop me 10 inches and i also hope to get smaller rear tires. maybe even try make it wider for better stability. i love how wide the tires i have on there now are but they are way to big at 20 inches tall

hey did you build that to race in a certain class or just for fun? its really nice

alright so if you look about midway down the first page you see my talking about lowering the seat and body to the frame. if you just take off the support holding the body and seat on it will sag and bend the body so here is my plan.


k so i think im going to cut the body where the red line in then take out the supports and weld the body back together where it sits. its kinda hard to explain but if you understand do u think it will work?