Mr.Modified's Simplicity Adventure Edition [2016 Build-Off Finalist]

Just make sure all the consumables you have replacements for. I would consider bearings and belts. I know you keep an extra...

It'd be a good idea to bring a guy with you on an atv for a trip like that, in case you had to get to a hospital quick or something. Even another guy with a tractor. Safety in numbers.

I could run support in the ranger. Extra gas and a set of tools. Plus documenting the ride. Might not be able to follow right along the whole way but would be within a mile or two and can assist in an emergency situation. A rollover would be fairly unlikely since most of the state is flat as can be. Haspin is about as steep as I’ve seen any of it.

It would kinda suck following in anything but a tractor as you have the ability to go fast and you can't, you gotta stay slow and babysit mr.moo lol.

I could handle it. As long as I’m in the vicinity I wouldn’t always have to be driving. Get a few miles ahead and relax for a few hours till I hear a distress call. Every once in awhile we check in on progress and if he got a few miles ahead of me I’ll jump back up in front of him

Yeah it would be nice to have a support team. Maybe also have some communication between the simplicity and the support truck. If possible it would be nice to plan out the entire route ahead of time to do a cross indiana run, not sure if that would be too easy though on back roads only. Maybe not so bad since a lot of it is flat as was mentioned. Here in new jersey we have a lot of twisting roads from all the hills ect.

And craftsmanquad, I didn't notice that you asked me awhile back if I did any port work on the simplicity engine. Sorry about that, sometimes I miss stuff people say on here if I don't take my time reading through. Don't think I did too much work in the ports. I actually couldn't remember myself and I took a look when I had the intake off lol. But this time when I had the head off, I did smooth/round out the eyebrows as most people call them on the block. I removed some of the area based on where the carbon had a flow pattern to it. You could see where there was a different color to it where it came from the intake valve and also headed towards the exhaust valve, so I marked the area and then sort of smoothed it down in those spots.

That should help a bit, in conjunction with the new carb

I got the new carb. A few issues.......

First of all, the throttle return spring holds the throttle wide open instead of closed. Not sure if that was some sort of factory mistake or what. There was no way to flip it the other way so it would work properly as it is wound the wrong way.

In the normal upright position on the manifold, the throttle (where the cable would attach) hits the exhaust pipe. It cannot be bolted on without cutting off a portion of the steel lever.

Bolted the carb on upside down to clear throttle lever. However, this blocks off the vacuum port that I added to the intake manifold. Decided to test the new carb with the frame mounted fuel pump only and not the built in carb pump. Didn't know if that would work or not.

Engine runs in this configuration but runs rich and loads up with too much fuel. Raw fuel spitting back from carb...

Removed carb, disconnected lines. Removed throttle butterfly and discarded messed up factory return spring on the shaft. Placed throttle lever and shaft in the vice and cut down to clear the exhaust pipe. Re-installed throttle shaft and butterfly plate. Bolted carb on engine in the correct up-right position. Disconnected vacuum to frame mounted pump and capped vacuum port. Fuel line connected to carb.

Restart engine... Runs good, pulls it's own fuel from the tank. Seems to be ok, no frothing or spitting of fuel. Runs under load, steady idle.

Now to rig up a new throttle cable holder and return spring holder. Then I need to adapt the hose to the airbox/snorkel. If all goes well, it should be ok. Better work because I'm running out of time for the top tractor challenge.

As with most things, there's always a few issues on the first run. Glad to here you got them sorted out and got it running!

Did you notice any difference in throttle response in the testing you did so far?

Nice write-up on your upgrade. Excited to see some video of the setup and running.

Thanks. Throttle response was alright. A little bit of lag if you get on it too quick but that was about the same with the old carb and not really an issue. It doesn't stall the engine, just has a slight delay. But only if you really whack it open. Normally, I don't think you would even notice it. The idle seemed nice and steady, so as long as that doesn't change and it runs ok, it should be a big improvement over the tecumseh float type carb.

Also, when I looked closer at the new carb, the high speed is not adjustable. You can swap jets but only the low speed mixture has an adjustment. Seems to run ok like it is though so I'll try it.

If I can I will get some video sometime, I haven't did much video for awhile. Need to invest in some new and better working equipment soon.

Worked all day today making a new throttle cable holder to fit the new carb and a return spring holder. I did some testing with the hood (and air filter) off the tractor and the carb was a bit too lean. As I might have mentioned, I found out only the idle jet is adjustable.

I tried cranking open the low speed jet a bit so the throttle response would pick up, but that wasn't enough. Helped to choke it slightly. So I removed the high speed jet and opened it up just a little bit with an acetylene torch cleaner. Like a tiny round file basically, if you've never seen one. (Horribly inaccurate way to do things, but I don't have the proper equipment)

Ideally, I would have a few jets to work with. Or next best, a numbered drill bit set. I don't have either.

So anyway, I did get it to run a lot better. Put the hood back on (connected the air box) and now, it's a bit too rich. It's darn friggin close I'll tell you.....but it won't quite idle. So I think the best thing to do is go back on amazon and buy another carb. Take the non messed up high speed out of it and swap the one I made bigger. I think maybe with the air box on, it's just restrictive enough that it will work. Probably should have tried it with the air box before I hacked it, but I didn't think it would change it that much.

Also I have been alternating between both fuel pumps, (carb and frame mount) and just the carb pump only. Doesn't seem to make a huge difference either way. I may even just put a fuel shut off in the vacuum line to the frame mounted pump so I can leave the lines on and mess with it either way. I had been trying to see if it gives it any extra fuel or not.

Equipment transfer at ATLTF President Fackler's HQ before heading out to the Top Tractor Challenge 2019


We did some advertising on the way and got a decent number of lookers at gas stations and along the highway.


Doug making the final checks before we left.

The team Simplicity pits at the Top Tractor Challenge.


#64 waiting in line for the last event of the day, the mud run. It had been raining mid way through the day and
had turned the last couple courses into a real mess. Conditions were tough. Notice the steering wheel more mangled
than usual and the back of the hood near the Simplicity S logo is crushed down. I flipped it over backwards on one of the
tougher obstacles in the course and narrowly escaped being crushed. I wasn't the only one. Luckly nothing serious was broken.


The Simplicity pits at night after a tough day. The tractor ran good and didn't give me any issues. At the end of the day my
alternator belt tensioner broke, but it didn't effect anything and wasn't related to any crash. Just broke from vibration. Other
than that, the hood needs to be straightened out a little and a new steering wheel wouldn't hurt. Ended up in about 7th place.
I didn't have quite enough power to compete with the front runners.

Nice writeup @mr.modified .

Looks like a good time, looking forward to the footage! I hope to compete at some point, possibly next year.

Will you and the #64 be making an appearance at haspin 2020?

Thanks. I might come out to haspin 2020, still undecided. We'll see how things go.

As for the new carb, it seemed to run decent enough, no flooding issues or starting problems now.
Might not be jetted 100% perfect but it was reliable enough. So for now I'll leave it.

Simplicity Racing's performance at the 2019 Top Tractor Challenge:

To start off with, the Simplcity Adventure Edition wasn't designed with any sort of racing in mind. It has a somewhat high road gear for long distance travel, but it's extremely under powered and has a lot of extra items bolted on which tend to add a lot of un-nessesary weight in a situation like the TTC. For example, the winch and the automotive alternator must add some 30 lbs and were completely unnecessary during the event. Also the hood rack for example adds some weight and at the worst possible location, at the highest point on the tractor. Under the hood is the spare belt and spark plug holders.

One of the main issues is that the center of gravity is a bit too high. This was partly done on purpose because I wanted the frame up high enough to get good ground clearance and also for getting through deep water. For steep hills I normally stand on the seat with my left foot, using the right foot to operate the throttle pedal. The I lean forward grabbing the front of the hood with one hand and steering with the other. This works ok, unless there's a situation where I have to use the clutch. On a steep hill, such as at haspin, either you make it or you don't.

At the TTC, I made it part way up this hill before the rear wheels lost grip and started sliding back. When the rear tires either hit the dirt at the bottom or got grip again on the ramp, the machine flipped. I opted to not try again, and so got a DNF for that course.


One thing I can say, is that the #64 held up extremely well under some fairly rough conditions and did more or less get through most of the obstacles. Even the hard hit from landing on it's hood did only minor damage. I was fairly rough on things during the event and I had no running issues at all. I think the limited HP tends to protect the drive train.


So even though I came in about 7th out of 10 tractors, from a technical standpoint, the tractor did what it was designed to do. Hold together and get you through any obstacle to your destination. Now I've gotta go back and design something specifically for off road tractor racing. A lot more power and as light as possible. No un-nessesary equipment. It should be rugged enough to hold together for an event, but not so overly rugged as to add un-nessesary weight. Also, the weight that is there should be positioned as low as possible while still leaving enough ground clearance to clear obstacles.

I would say one of the most important things to consider is weight distribution and center of gravity. All lawn tractors for the most part don't climb hills that well since your more or less stuck sitting over the back wheels. The thing is to find the right combination. Too low and you might have great center of gravity and hill climbing ability, but your not going to get over any logs. Too high and your flipping over all the time. Over-all the #64 does fairly decent for what I need it to do, and I think I'm fairly close to being done with any serious modifications to it.

Nice write up! I totally agree with you on purpose built machines, the simplicity does what it was intended to do and it does it quite well. I was pleasantly surprised at how well it took that rollover you did a great job. My haspin build is very well built but has entirely way too small of tires to be even somewhat competitive in the ttc, but just like the simplicity was purpose built, so was my haspin build and some people don’t understand that when comparing machines. I’m very excited for what you build for next year I’ve always liked your build style

Thanks. And yeah there's really no way to build a machine that works for all types of terrain. If you go too far in any one direction, I think your gonna lose it somewhere else. You just gotta find the right balance for what you want it to do.

Yeah the simplicity is a pretty awesome machine.  It was the inspiration for my Kal-EL build.

Thanks a lot, your machine turned out pretty nice.

Now I've gotta find a new steering wheel at some point and maybe straighten out my hood a little, then i'll be good to go. I'm surprised the steering wheel didn't break in half yet with how many times it got bent.

mr.modified wrote:

Miami Simplicity Racing's performance at the 2019 Top Tractor Challenge:

To start off with, the Simplcity Adventure Edition wasn't designed with any sort of racing in mind. It has a somewhat high road gear for long distance travel, but it's extremely under powered and has a lot of extra items bolted on which tend to add a lot of un-nessesary weight in a situation like the TTC. For example, the winch and the automotive alternator must add some 30 lbs and were completely unnecessary during the event. Also the hood rack for example adds some weight and at the worst possible location, at the highest point on the tractor. Under the hood is the spare belt and spark plug holders.

One of the main issues is that the center of gravity is a bit too high. This was partly done on purpose because I wanted the frame up high enough to get good ground clearance and also for getting through deep water. For steep hills I normally stand on the seat with my left foot, using the right foot to operate the throttle pedal. The I lean forward grabbing the front of the hood with one hand and steering with the other. This works ok, unless there's a situation where I have to use the clutch. On a steep hill, such as at haspin, either you make it or you don't.

At the TTC, I made it part way up this hill before the rear wheels lost grip and started sliding back. When the rear tires either hit the dirt at the bottom or got grip again on the ramp, the machine flipped. I opted to not try again, and so got a DNF for that course.


One thing I can say, is that the #64 held up extremely well under some fairly rough conditions and did more or less get through most of the obstacles. Even the hard hit from landing on it's hood did only minor damage. I was fairly rough on things during the event and I had no running issues at all. I think the limited HP tends to protect the drive train.


So even though I came in about 7th out of 10 tractors, from a technical standpoint, the tractor did what it was designed to do. Hold together and get you through any obstacle to your destination. Now I've gotta go back and design something specifically for off road tractor racing. A lot more power and as light as possible. No un-nessesary equipment. It should be rugged enough to hold together for an event, but not so overly rugged as to add un-nessesary weight. Also, the weight that is there should be positioned as low as possible while still leaving enough ground clearance to clear obstacles.

I would say one of the most important things to consider is weight distribution and center of gravity. All lawn tractors for the most part don't climb hills that well since your more or less stuck sitting over the back wheels. The thing is to find the right combination. Too low and you might have great center of gravity and hill climbing ability, but your not going to get over any logs. Too high and your flipping over all the time. Over-all the #64 does fairly decent for what I need it to do, and I think I'm fairly close to being done with any serious modifications to it.

looks like it worked out well even after smashing it up....

I noticed that about my tractors, I can take the deck of a crappy lawn tractor throw some atv tires on and it skips across the rocks no problems because they are so light, a cub cadet or tractor twice the weight will struggle & spin tires across the same spot. The lawn tractor will fall apart shortly thereafter haha. Its a balance between good strong parts & dead weight.

The front tires on this could be a bit softer. The suspension takes care of most of it but even so, I think softer atv tires might be a better ride. It's not too bad though. I still think this machine would be good for a long distance run somewhere. I'd like to try that if I can figure something out.

Me and a couple buddys are talking about running the KAT on dirtbikes in the next couple years, I’m partially doing it to scout it for a tractor Adventure, I think it would be really cool to do a 3 or 4 day long distance off-road mower adventure.

Yeah if there was a good spot, I would definitely be interested in doing something like that. That would be pretty cool. Once I get my supplies trailer ready to roll.