6 speed big bore stroker 3 wheeler with tracks

[Carman]

i know its not a dirt bike but its the same motor and I'm not sure where else to post this and someone might find it interesting

this is more of a project to see if i can do it more than the need for a snow vehicle. i have a running snowmobile and am possible looking at a used timbersled long track for 4k with low hours for my husky.

anyway i have a 1983 Yamaha YTM200EK 4 stroke shaft drive 3 wheeler that is my daily driver and gets used more than all of my other bikes combined. it will wheelie in any gear and weighs under 300lbs. anyway its pretty good in the snow so naturally i want to put tracks on the back and a ski on the front.

picked up a super cheep master craft mig welder (280cdn+tax for mig welder and welding cart) and so far I'm really impressed. i use a lincoln migpak 180 at work and i find this one works Almost as well for a 1/4 of the price. 

the first thing is a motor upgrade consisting of moto4 200 engine cases and reverse parts with a ttr225 6 speed transmission (6F/6R), tri-moto or moto4 225 crank (longer stroke), moto4 225 cylinder bored to 72mm, ported head, stiffer valve springs, bigger cam, new clutch and a bigger carb. exhaust may come later as i like it quiet. the engine will be getting a full rebuild plus the parts mentioned above. should be around 240cc and hopefully 20ish hp

the engine family consists of the  ytm200/225, moto4 200/225/250, bw200, tw200, ttr225/230, xt200/225 pro hauler and finally the timberwolf/beartracker 250 quads. some engine cases, top ends, clutches and many other engine parts are shared between them.

 

finally the tracks will be made from mid 90's polaris indy wedge chassis rear suspension and drive sprockets with 121'' tracks.

my goal is to have the whole assemble removable in a couple hours and entirely bolt on. i will be welding bracelets onto the frame but nothing that will get in the way.

my plan is to build brackets with bracing all the way back to the rear mounting points on the rails to hold the driveshaft with drive sprockets on place and keep the track tight. the driveshafts will be coupled together and run right behind the motor above the bottom framerail and held in place by a 1.5"x2.5" rectangular tube with brackets welded to it and flange mount self aligning bearings to hold the drive shaft. i have a bunch of spare axles so i can cut the ends off a 3 wheeler axle and put a keyway and industrial #40 chain and sprockets on the outside by the disc brake housing and run forward to the snowmobile driveshafts to allow me to get the tracks farther forward and get the ratio i need. the drive sprocket on the rear axle will be 48t and the driven sprocket on the tracks will be a 15t.

the rear portion of the tracks will be sprung by one xl100 front fork per track from the rear bar of the trike to the rear of the sled suspension. this will allow me to drive through ditches and gullies.

the pivot will use 4 greasable weld on gate hinges

 

i will be updating this as i make progress. next is getting more steel and bearings

[Dirt Hokie]

 I am on board with this.  Of course a balloon tire three wheeler is pretty unstoppable as is.    

[Carman]

 

On 11/15/2017 at 5:11 PM, Dirt Hokie said:

 I am on board with this.  Of course a balloon tire three wheeler is pretty unstoppable as is.    

yes it is. it actually floats as well. i have most of the subframe built now. il take some pictures tomorrow.

[mlatour]

1983-85 that sure was a great 3-wheeler era, myself on an 1984 Honda ATC200X at the time.

 

Still a novelty, rare ATV's rather piqued the general public's curiosity rather than annoyed them. 

Pre-cell phone era so less likely anyone bothered calling the cops when we regularly connected trails thru city streets.

 

Nice project, reminds me of the WW2 German army SdKfz2  'tracked' motorcycle.

Maybe mount a ski in front for snowy conditions ?

Edited November 23, 2017 by mlatour

[Carman]

17 hours ago, mlatour said:

1983-85 that sure was a great 3-wheeler era, myself on an 1984 Honda ATC200X at the time.

 

Still a novelty, rare ATV's rather piqued the general public's curiosity rather than annoyed them. 

Pre-cell phone era so less likely anyone bothered calling the cops when we regularly connected trails thru city streets.

 

Nice project, reminds me of the WW2 German army SdKfz2  'tracked' motorcycle.

Maybe mount a ski in front for snowy conditions ?

I was thinking about a ski but I am on roads and such often so I'm thinking about cutting a track shorter and wraping the front tire in 1" paddle studded track. front end is incredibly light anyway

[Carman]

anyone ever seen a oil pump in this bad of shape? bike was still running and driving but cam was flopping around in the head. the end of the cam had 1/4" of play up and down. rockers were missing over an 1/8" if material. ticked a bit and down on power. crank bearings were totally toast. cylinder was scored. overall petty bad. the cases are going to house the new 6 speed 240cc engine as they have reverse.

[Carman]

sorry i haven't updated this in a while. I've been working on it but not taking enough pictures and haven't had time to do an update. so here is the progress. i should also mention that i am not a welder and this is a crappy tire unit that was under $300

i am using #50 sprockets with 520 O-ring chain for drive. 42T drive sprocket and 15T driven sprocket should get the correct ratio i want

the 3 wheeler the first post is also not the same as the one pictured here. got another one to build this on and keep my good one running

[Carman]

currently waiting in hinges to build the track frames and machining done on the drive sprocket shafts

[Hudson Charlton]

Good for you!

[mlatour]

Was curious to see the original shaft drive and rear axle design on that as Yamaha 3-wheelers weren't very popular in this region.

In my teenage years of riding ATCs pretty much everyone had a Honda,

locally there was only one Yamaha, a 225DX owned by an older guy who didn't ride with us.

 

Perhaps a regional preference thing but even when the market switched over to 4-wheelers (late '80s)

despite plenty of dealerships of all brands in the area, 

Honda & Kawasaki were very common, yet Suzuki and Yamaha ATVs were nowhere to be seen.

Edited December 5, 2017 by mlatour

[Carman]

8 hours ago, mlatour said:

Was curious to see the original shaft drive and rear axle design on that as Yamaha 3-wheelers weren't very popular in this region.

In my teenage years of riding ATCs pretty much everyone had a Honda,

locally there was only one Yamaha, a 225DX owned by an older guy who didn't ride with us.

 

Perhaps a regional preference thing but even when the market switched over to 4-wheelers (late '80s)

despite plenty of dealerships of all brands, Honda & Kawasaki were most common, Suzuki and Yamaha ATVs nowhere to be seen.

I have never seen a Kawasaki or Suzuki 3 wheeler. they don't seem to exist here. I prefer this Yamaha over the Honda atc's as the engine is tucked way in the back and the bikes are much lighter. its damn peppy for a 200 4t from 1983.

here its a 25;1 ratio of Honda to Yamaha but these Motors are used in so many bikes its not and issue. a motor from a 2003 timber wolf 250 4x4 will bolt right into this with no modifications other than wiring.

I have confirmed that a 6 speed from a 2003 ttr225 will fit in this with some countershaft modification. its a direct drop in for the chain drive models.

in the stock configuration the rear end allows water to flow through unsealed bearings and through crown gear. I put sealed bearings in it when I rebuild the rear end. disc brake works really well.

[Carman]

UPDATE

i have one side mostly together with the pinot finished for the track. its not going to be able to move up and down as much as i had hoped but I'm guessing around 24" at the end of the track up and down before the front of the track skids interferes with the track.

[Carman]

this is my running 3 wheeler that i use to haul wood out of the woods with and trail ride. its hauled alot of hardwood through a swamp and out to the piles 

[mlatour]

Just like the good old days of simpler ATVs and dirtbikes,

200cc or so, 2-wheel drive, solid rear axle / no rear suspension and, still gets the work done.

 

Nowadays no one would dare consider having less than a fuel injected 700cc, 4-wheel drive, power steering, winch etc.

equipped ATV to do exactly the same work.

Edited December 28, 2017 by mlatour

[David John Whelan]

That's a cool project but I wouldn't install the 6 speed trans in it  , you got a lot going on back there and the gears on the 6 speed trans are thinner and might break , just a thought 

[Carman]

4 hours ago, David John Whelan said:

That's a cool project but I wouldn't install the 6 speed trans in it  , you got a lot going on back there and the gears on the 6 speed trans are thinner and might break , just a thought 

i have both 5 and 6 speed transmissions side by side and the gears are the same width. I've looked it over a few times and i think the 6 speed is stronger. 

[David John Whelan]

That's odd , we replace all the new yz250fx transmissions with yz250f model transmissions cause the gears are wider and won't break like the 6 speed fx trans , I figured when you could swap transmissions from 5 to 6 speed they are all like that but I guess not , keep the build updates coming ?

[Carman]

22 hours ago, David John Whelan said:

That's odd , we replace all the new yz250fx transmissions with yz250f model transmissions cause the gears are wider and won't break like the 6 speed fx trans , I figured when you could swap transmissions from 5 to 6 speed they are all like that but I guess not , keep the build updates coming ?

the shifting dogs are wider on the 5 speed and there are a couple spacers. I'm surprised the fx transmissions are weak enough to break

[Charles Gunzelman]

How far did you get with this?