Craftsman lt1000 drift build

Hey guys, I have built a couple drift builds in the past, if you wanna see they are on my tiktok, but this one I think will be the cream of the crop. It’s a 1999 lt1000 with a twin carb tecumseh v twin, 691cc, not very stock at all, backed by an mst-206, oil filled. As the tractor sits now it is geared for 31 mph at roughly 7000 rpm. The way I make these drift is with a set of 20” ID pvc sleeves that go over stock turf tires, and a locked diff. It’s an incredible amount of fun, I’ll post videos of this one drifting when I’m able to afford a solid axle shaft to doc lock it, normally I just fozzy lock em and run em for 6 months until the cases crack, but this mst-206 is in EXCELLENT shape and I’d like to keep it that way.

Excellent!  I have created a new TicTok field in the profile.  I hooked you up with an update.

Also, you can use the Embed button the [</>] next to youtube button if you want to embed your TicTok videos.

That’s incredible! Thank you! I have poor service where I live and it takes about half the time to upload to tiktok versus say YouTube or Facebook so this is super helpful!

This is one of my friends running it up the little hill climb, he kept lifting off the throttle for traction

This is the first drift tractor, had a vanguard v twin, less than stellar.

Just realized I haven’t put any pictures up of this tractor, or the header I built for it.

Isn’t that just the worst looking abomination you’ve ever seen. I hate that it needs a hood scoop to stay cool at higher rpm/speed

Maybe you could restyle the scoop to look like the ones on the supercharged street cars. Just my .02

Yeah I’ll probably just cut it off and shorten it by an inch and a half, hopefully that will make it not look like such a monstrosity

My vote is to cut it down so it's about 1.5"-2" tall, turn it around so it's a cowl and install a hood-to-engine shroud, it would look much racier and still be functional!

If it was just for looks I would 100% do that, cowl induction looks WAY cleaner in my opinion. However since this is for more of a “cram as much air through that engine shroud as possible” kinda thing I’m worried the cowl induction wouldn’t work efficiently. Especially since the speeds this thing sees aren’t fast enough for the aerodynamics to work for a cowl induction

I am curious how you guys think it would work to trim the bottom of the cylinder shrouds, I’m talking in such a way that the cooling air travels from the top (through the flywheel) and out the bottom of the cylinders. The way it’s designed now it shoves all the air out through a “small” slit on the inside edges of the cylinder wall

It will actually provide more cooling than just forced air if you were to build it properly and be more consistent because it would be pulling cool air as the engine runs not relying on speed to force it. The trick is to size it well, especially the intake portion so it's a small enough "intake" that you can feel a little suction and or draw smoke into. You'd need to make a sealed box that attaches to the hood under the louvers that will extend down and seal on the fan/flywheel shroud, some tractors have a half a$$ed one as it is and just like a old car... that shroud directs the air to where it needs to go, in your case directly into the flywheel.

You could also add small forward facing scoops on the sides of the hood/grille/body and build air delfectors inside to direct forced air on to the heads/block.

I wouldn't steer you wrong!

That all makes sense, the problem I’m having grasping is that the engine couldn’t pull enough air as it was to keep it cool, so how would building a hood shroud and sealing it up help any with a cowl induction? Like I could see it with a ram air because then there’s an outside factor other then the engine fan moving air, but how is that so with a shrouded cowl induction? I’m not quite understanding

As long as you have some suction it really doesn't matter which way it faces, a good shroud is what's important. If you have a little suction at the "intake" then you're creating a low pressure area ahead of it (vacuum) and are getting the most air possible into the flywheel fan, similar to a venturi effect but not exactly the same. Air velocity is the key and a well designed hood-to-flywheel shroud can provide it.

Just out of curiosity have you actually taken the temp of the block/head(s)?

No I haven’t put a heat gun on it, but it felt before the hood scoop quite a bit hotter than my last v twin, which was a vanguard, and after it feels cooler, I should probably put a temp gun on it lol what are these engines even supposed to run at for temp?

Air cooleds run a lot warmer, about 300-400 degrees I believe. If you’re concerned it might be worth cleaning the fins out and checking to make sure it isn’t lean at all.

The fins are clean, I clean them often, and do you know of anyone running a wideband o2 sensor on a mower to absolutely know afr?

Never heard of it. Reading spark plugs and going by smell is a good indicator. Try richening the carb up a hair, you should not smell fuel but it will make the engine run a bit cooler.

To tune a carb, I was taught to turn in the mixture screw until the engine runs rough, then turn it out again until it runs rough again, then go in the middle. If your plugs are white or reddish, it’s lean. Black is rich. A dark brownish gray is the happy place.

ZSmachines wrote:

No I haven’t put a heat gun on it, but it felt before the hood scoop quite a bit hotter than my last v twin, which was a vanguard, and after it feels cooler, I should probably put a temp gun on it lol what are these engines even supposed to run at for temp?

190-220 degrees is pretty good for seemingly all internal combustion engines from nitro RCs all the way up to your basic automobiles with 200ish being optimal. I've temp'd a few good running small engines and they're generally within this range when heat soaked but under a light load. The cylinder itself under the head would be the best place to take a temp reading.

@Rustbucket Garage makes a good point in regards to tuning/reading plugs and unless you've done extensive internal mods you should stick with factory plugs, doubtful a intake/exhaust would warrant a heat range change but the plugs will tell you that as well!

Never heard of anyone using a o2 sensor on a small engine before but I'm sure it's been done, I've even considered it myself but figured it's more trouble than it's worth.

Hood scoop won't really do nothing anyway but helps with the cool factor.
If the end result is drifting that means low speed and sideways driving neither of which are helped by a front facing scoop.

An external oil filter with oil cooler or a bigger oil filter might actually be more helpful even.

@fbisurveilancevan Please note what I've written above in regards to building a proper intake shroud in case you missed it, I'm extremely confident it would work to provide better cooling.

Brian, I’m planning on doing exactly what you suggested as far as cooling shroud, rust bucket, I know about reading plugs, but great tips! and I absolutely would have just richened the mixture to cool the engine down but, like most great things, the EPA ruined it and decided these carbs shouldn’t be able to be adjustable. So in order to richen I have to pull the carbs and open the main jets the exact same amount and it’s honestly just a pain so I’ve been putting it off. Thanks to everyone for all the info and tips, it’s better to have too much information than not enough lol

Cool @ZSmachines! I'm sure you'll be happy with the results if you take your time and design it well! We're expecting progress photos! Lol

I know what you mean about the EPA carbs, yes they're a pain but I find a pin vise works much better than a torch tip cleaner to step  up jets a bit and if you go too far you can always solder the hole closed and start over!

This is the kit I have and it's worked great, under $20 on Amazon.

I’m going to have to pick one of those up! Never hear of a pin vise but looks perfect for drilling jets lol, tomorrow is payday so planning on picking up some 10” diameter ducting to cut up and make what will basically look like a massive carb hat to mate up to the hood scoop