T-Dub's Simplicity 738 Broadmoor Rally Project

Well Guys, It's been a while since I've been on here. Had a good summer / fall racing vintage dirt bikes and now it's time to get back into TRACTORS!!! I had been running my Murray pretty well. Using it for adventuring, playing and yard work. I blew the Peerless 920 Transmission so many times, I ran out of spares and gave up on the tractor.

So, I picked up my old Simple-City. and planned on building it when I had time. I posted a couple updates on the "What have you done to your tractor today" thread, but I figured I'd start a thread and throw up a couple pictures on here. Enjoy!

Here's where I started: Simplicity on the trailer, pulled it out from under a bush where it had been sitting for almost 10 years.

I started the build by swapping the 12hp motor.  It's the "Low Buck Flatty" that I built on Doc's thread that I inadvertantly hijacked.  It's the best motor I've ever ran or built.  Plenty of low end and mid range power.  And has a good top end too, but the power is still down low in the RPM's since I'm running a stock cam.

Anyway, the swap went well, but there were a few challenges to overcome.  The new motor is physically much bigger than the stock 7 or 9 that was on it.  



After getting the motor in I had to cut the hood, cut the grill, eliminate the tall oil fill tube and mess around with a bunch of other stuff to get it to fit right. Here's a pic showing the hood not fitting and the grill not quite fitting. Front tires are on with bearinged rims and push bar lightly bolted on.

Also, in the pic above it shows the clutch pedal already moved to the left side of the frame.

I started on the exhaust next (I think).  Header from the motor had to turn the other direction.  Not a lot of room in there, so I decided to run it around the front.





Then had to figure out how to connect it so I could take it apart if needed.  I didn't want to weld it all together because I'd never be able to remove it.  I dug deep in the scrap pile and came up with the bicycle seat clamp from the bike I hacked up to build the original exhaust.  PERFECT!

I mounted the Cherry Bomb and fitted a new pipe to connect the two EXH components.  Some more welding and fitting and done!

I also had started fitting the foot throttle pedal.



I don't have a great picture of the finished EXH but I'll get one.

Here's a pic showing the back of the fan/flywheel housing up against the fuel tank.  There's enough room to maybe pass a toothpic between them.  And I had to hammer a small flat area into the back of the housing without caving it into the flywheel.



And still the front of the motor wouldn't fit.  So I had to hack the grill on the air cleaner side and cut out all the bars in front.
I also had to cut the hood to clear the Air Filter and move the hood mount bolt location.

Next was the rear wheels.  Many challenges to be overcome here.  
First, the original rims were too narrow.  And I didn't have any other rims that would fit the massive 1" axle shafts.  
So, I had to stick with the original rims and widen them.  
They also were mounted inboard too far, so I re-drilled the holes for pinning them to the axles.  (There are no keys on this axle).

Pic of trying to figure out what to do....  I had some wide golf cart wheels, so I cut the outside part of the rim apart and fitted them into the inside of the Simplicity Rim.  After carefully measuring and welding them together, I cut the original outer bead edge off and sealed the rim with bead sealer.





So this is where it stands now.  I will get some pics of the belt nightmare that I had to deal with.  It's still spitting off the belt once in a while, but I've taken it up and down the street and it is pretty fast.  I'm happy so-far.  More work to do and more pics to take for you guys!  More later.

Here's a couple pics of it sitting out in the crappy rainy new england weather.  Poor girl!

Oh, I forgot to mention that the rear wheels still didn't fit, so I had to cut the fenders!

Next on this project is some paint so my welds don't rust up too bad.

What do you guys think of the rims? White? Black? I'm not sure what color would look best.

Gotta paint the exhaust and Cherry Bomb too. VHT black for the pipe and RED for the 'bomb.

Paint the rims orange/red to match the tractor!

+1 on matching orange.

Looks good! How many gears in the trans., and is it already locked?

Show us the belt routing!

this is cool! i love the older tractors.

Thanks Guys! I will look for some orange paint today. How about a couple 01 General Lee stickers? LOL!

Maybe get into the belt and take some pics while I'm trying to get it to behave.

Trans has 3 gears and reverse. I only used 3 gears on the Murray, so I'm glad this one is just 3. OMHO, any more than 3 gears is just splitting slow into slower and not fast enough. Who needs that?!!! This one happened to turn out nice, with 1st being about 2-7mph: perfect for hauling the cart. 2nd is a nice travel speed. Good for medium cruising if the trail is rough. I think 3rd is pretty quick. I will get some video of me ripping it WFO in 3rd so we can see. It will look different than it feels, but it feels fast at least.

Many more little tasks to complete before this is they way I want it, but starting with a solid, well built machine is a welcome change!

TheRainbowBoxer wrote:

Paint the rims orange/red to match the tractor!

Yup yup yup! Re paint the dash and air box white and would look great

Took the Simple-City out for a romp and lost the belt like 10 times. So again, I reconfigured the pulleys and it seems to be working OK.

Here are a few pics of how I had to run the belt.

Full Underneath


Clutch and Idler


Another Idler where you can't see it. I ended up swapping this pulley for a V one. It goes above the clutch.


Added this Idler as well to help get the belt lined up for the horizontal trans pulley. Needed it because the engine pulley is so much bigger now.


So, now it goes fast enough in 3rd that I get massive High-Speed Wobble out of the front end. I'm not sure whether it needs more toe-out or maybe it's just because the bushings in the king pins are worn. I guess I'll replace the bushings first, then build an adjustable tie-rod to play with the toe-in / toe out.

nice build love it

Welp, It's almost a year later and I figured I'd provide an update.

This Simplicity is a beast. I use it all the time and it just keeps going. The Low Buck Flatty was THE ENGINE to build. I highly recommend anyone thinking of building a 28" motor look at that thread. And again, thanks to Doc for all the help. This motor is amazing.

I got tired of having to rev the motor to get it to charge the battery, even though I put the strongest B&S Alternator I could find. But I idle it too low and start / stop it a lot when doing yard work. Plus I'd like to add some more lights and the current alternator can't handle the ones that are on there now.

SO! I went to the local bone-yard and picked up a Delco SI10 Alternator. Used the original Starter / Generator mount to bolt it onto the motor. I need to fit a new belt, but soon I will have 63 amps to play with.

Here's a couple pics.

that's awesome how you used factory simplicity parts to mount the alternator.

Thanks man. I try to keep things as simple as possible. Glad I saved the old motor for parts etc...

When I built this 12hp flatty, I was lucky enough to find a crank that had the pull start "shaft" sticking up past the flywheel. This way, I retainer the pull start, but then was able to switch to the pulley for the alternator.

Even with 63 amps now I'm a little leary of going too far without a pull start, so that may be the next mod. I'm not sure I will be able to mount anything on top of the flywheel though.... I'm thinking about a pulley on the transmission jackshaft.

The arrow points to the jackshaft on the other side of the trans. I could use that for a pull start I guess if the belt doesn't slip.

I think the belt might slip, especially with how much compression the engine has. I actually run an extra pulley on the crankshaft with a notch cut in it for the pulstart.

The old allis chalmers garden tractors had the fender flip up and notches for a pull start. buddy had one. Should work if you can have it come up thru the fender.

That's good to know Redline!  I think it might work.  The clutch is wicked on this thing, so I don't think the belt will slip.  I guess I'd have to sit on the ground and pull the rope backwards.  

I had a dog that ate an entire set of pantyhose... Had to pull the pantyhose out of her butt the same way, next day LOL!!!

I hate the twisted belt setup on those things. Mine kept getting messed up too. Looks nice jacked up with those tires though.

Yeah, the belt set up was a true PITA to get to work correctly. It took a LOT of adjusting and modifying since the different size pulleys put the belt in a different path. Needed to modify the clutch and pulley too.

It hasn't chucked a belt in quite some time now and it was worth the effort 100%. I would have blown several more 900 Peerlesses in the past year, but this transmission is a stone crusher.

I do still need to get under there and weld on some sort of Articulation limiter, sort of like a steering stop on a motorcycle. It articulates too much and the clutch pulley grinds against the frame. Plus it's just too wobbly for me.

With mine my knees would bang against the sides of the dash when driving over rough stuff. I was always going to just weld it solid.

Holy moly man, that dog comment had me ROLLING.

We had a 728 simplicity at our camp to mow and the twist belt was odd, but the twisting mower belt was more trouble then the drive belt

True story. Yeah, twisted belts can be a savior when done correctly, but so much work to get it right, it's almost not worth it. Well, it was worth it for me because for the first time ever, I've had a transmission last longer than a piece of bubble gum.