my soon to be modified yerf dog

[oorgle]

Hi, been lurking the forums for a few months and finally got around to taking some pics of my kart, so i thought i'd make my first post and show it off.

its a yerf dog that i bought about 6 months ago not running. had a 3.5 horse tecumseh and a clutch that i replaced with a 5.5 horse briggs and torque converter. its still not as powerful as i'd like so i am going to cut up a chinese knockoff quad i got for $400 and steal a bunch of parts off it.

 

[oorgle]

here is the quad i'm using for parts. it is 150cc with single rear disc and dual front drum brakes. no reverse . it has electric start and automatic transmition.

I plan on taking the front shocks off the quad and making them the rear shocks on the kart, i'm taking the headlights, taillight and battery, taking engine, brakes, transmition and sprockets and the gas tank. with a little luck i hop to have all this finished in about 2 weeks.

 

[ironman]

cool what a great start to a fun looking kart keep us posted

 

[crazycart]

I would personally Take off the whole rear swingarm/axle setup off the quad and mount it on the rear of the cart,you'd have a better axle setup and suspension.

 

[oorgle]

i actually plan on extending the whole rear section of the kart and lengthening the swing arm. the quad motor is horizontal and takes up alot more space then the briggs does.

i can't use the axle off the quad as it is to short, its a good 8-10" shorter then the kart axle, but i beleive both are 1" and i should be able to mate up the quad parts to the kart axle without to much trouble.

 

[oorgle]

my attempt at completing this in 2 weeks has been hindered by excessive heat in my area over the last week. but it finally cooled down enough to play around in the garage

i started tearing down the quad a bit today, took the gas tank off, the rims/tires, all the plastics, the front brakes, battery and some other small parts.

I'm torn on how to construct the drive train. I have a swing arm right now that works alright. to use the quad engine i either have to lengthen the swing arm by up to 6" (due to the transmission) or start from scratch and build an independent rear suspension.

i personally don't like the feeling of the rear suspension dropping due to engine weight when i hit a big bump or jump so that is why i am thinking of independent rear.

i'll have a pic of the kart with the quad rims and tires sort of mounted later tonight. it looks much meaner with quad tires

 

[ElectricalBen]

if you need some ideas i felt exactly like you and used a 4 wheeler close to yours but i dint have the engine from it but look at my post (im building a cart got 60 pics) under the project log picture section and i have a seprate suspension but i put my chain tensioner on the wrong side

 

[oorgle]

me and my roomate got to brainstorming and i have decided to use a swing arm but have the engine fixed to the frame. I'll be building a chain tensioner so no worries about the chain falling off.

here is some pics from last nights work. nothin to major just some new rims and tires and a shot of the quad engine.

 

[oorgle]

i chopped up the quad with a sawzall today and pulled the engine out. I also removed the swingarm/engine assembly from the kart to make room for the new engine and swingarm. we left the top rails of the quad frame intact to make make mounting the engine easier.
we set to motor in place and it looks like it will work out much better then i had hoped as far as spacing goes. i'll have pics up soon of the progress.






Ben i like your chain tensioner. i plan on building one very similar to it. where did you get the sprocket and how is it mounted to the square bar. also how does a chain tensioner effect gear ratio ?

 

[ElectricalBen]

well as you might be able to see it is on the wrong side but thats because i didnt think to much when putting it on.. i found it at tractor supply its a tractor sprocket so its bulit really good. i have had to work so havent had the time to fix it but it doesnt hurt ratio because it just spins. and good luck because this is one of the hardest desigins and your the first person other than myself ive seen attempt it and good luck its alot of tedious work i know.. and i have the same tires as you but they werent in as good of shape so your lucky there.. and its looking good..

 

[oorgle]

here are pics what i did today. I cut the backbone of the quad out along with the engine. i cut it long to test fit it in the kart. as it turns out, it fit almost perfectly where it needs to be and the backbone will require minimal work to attach to the kart frame.


whats left of the quad

the engine/tranny with backbone attached

a shot of the other side of the engine

rear shot of engine set into kart

 

[T-BONE]

How fast are you expecting it to go?

 

[oorgle]

my goal is to get it up to around 50 on level ground.

with the old briggs setup i think i hit about 45mph but i was going downhill with my foot to the floor. but as soon as i hit even the slightest uphill it would drop down to about 10mph.

 

[oorgle]

sadly not much real work has been done on my kart as of late. after racking our brains for a couple hours me and my roommate found out the swing arm and tensioner won't work. the positioning of the transmission leaves no room to mount a tensioner. with a different engine this setup would probably still work. The heat has also been crazy here lately. it was over 100 degrees here all last week

So, instead of a swing arm we are going to build a single A-arm independent rear suspension. I ordered the u-joints yesterday and i'm going to go get the rest of the metal i need on saturday when i have time.

one of my front A-arms is racked from the previous owner's kids crashing into a tree so we are going to rebuild that. I am also going to build a completely new rollcage as i have already smacked my head on the current one enough times.

once i get some steel here I'll have a bunch more pics to show you guys

 

[2or3wheels]

It that a liquid cooled 2 stroke motor?

 

[crazycart]

Lol the exact opposite, Air cooled 4 stroker

 

[oscaryu1]

45MPH downhill? It's in its "overdrive" mode. Uphill? In its torquey mode.

 

[2or3wheels]

what, theres no cooling fins?

 

[Kenny_McCormic]

what, theres no cooling fins?

It works on magic. The jug is covered by a plastic shield that directs air around it being pumped by the squirrel cage fan seen in many of the engine pics.

 

[2or3wheels]

wow, never seen that, hopefully you'll get the power your looking for.