When I was a wee youngin (early 70s) my father had an RC that I was absolutely fascinated with. It was orange and brown and looked like the car from Speed Racer, and infact wasn't RC. It was controlled by a tether which looked similar to a handle for waterskiing, and the only thing you could control was the throttle. It also had the troublesome .49 engine (I think) and was a bear to start and keep running.

But the interesting thing is it was prop driven from the rear! So you would stand in the center of the yard and this thing would do a 50 foot circle around you and just kept going faster and faster. I have no idea who made it and haven't seen another one since. In my recollection it seemed like a 5th scale but it was probably 10th scale.

That sounds like the old Cox tether cars. There was the "Prop Rod" like the picture here, but I don't remember it having a throttle. Maybe there were others that did though.

This thing was much bigger and did have a cable going to the throttle control. And I'm not even certain about the size of the engine. But I do remember if you got it to run it was a beast lol.

That engine came out of a broken up plastic fighter plane my dad had found. The plane wasn't fixable but did have a bomb on the bottom that could be dropped. There were three control lines. The black part is the tank.

All cool stuff here guys!
I am an RC fan bigtime! I have an active YouTube channel that specializes on more "entry level" RC gear. Love it all.

Baja 5b update
 

Well I got a new clutch bell housing on the way, along with a wheelie bar, 1" hub extenders (it'll be 22" wide), a spark plug, and a throttle/brake linkage that I'm gonna rob parts from to guarantee my brake can't stick. I also got a 19 tooth pinion and a Hostile nylon spur gear which is supposed to be the very best. The stock 17/57 ratio does 41mph, the 19/55 ratio should net 48mph and make it a little easier to control offroad.

But I also ordered a 55 tooth metal spur gear and here's why. I'm in a couple of Baja groups and the general consensus is if you have the HD alloy differential and gear set (which I do) then you should be just fine running the metal spur gear. One fella on there has 8 Bajas and he runs the metal spur in all of them. So I'm gonna run the Hostile nylon spur, but if it fails anytime soon the metal spur will take it's place. Also the factory nylon spur is $7 with free shipping, the Hostile set me back $38 with shipping.

More fun facts, the stock small blocks (23 to 30.5cc) put out 2.3 - 2.8hp. My big block 360A puts out 4.1hp from the factory. Port and polish will add 1 additional hp, and a RB Innovations belt driven supercharger ($300) will add another horsepower for a total of 6hp. But for the low low price of $800 you can buy a Japanese Zenoah 34cc that puts out 14.8 horsepower which is about the same as my Hawk 250! OBR and a couple others make hot motors too but they're a $1000 and up.

And when I decided to get back into this hobby I told myself I wasn't gonna spend much money this time around.. :hehe:

One legged, you dont happen to have one of those stock engines laying around collecting dust mayhaps? I have been looking to upgrade the power output of my boat from the 1.2hp 4 stroke weedeater motor...

Haha! I'm not sure how they measure hp on your weed eater, but you can look up several videos on YouTube. They measure these at the rear wheel on a RC dyno. And I haven't seen too many weed eaters with a tuned expansion chamber pipe, but I haven't seen your setup.

I also ordered a silencer for the pipe, its just a little thing about an inch and a quarter long. I've seen GPS speed runs and the silencer doesn't seem to hinder it. Even if it does I'll still run it, right now it's so loud it hurts your ears.

i can only go off the specs of Stihl, and what they say it puts out...LOL as for my exhaust, its a straight pipe since its a 4 stroke machine with one of the silencers you mentioned... which is literally just a mini glasspack... i dont really notice any difference in volume....LOL

also, heres the stock exhaust of my FS130 (1.9hp, 36.3cc) 4 stroke:

https://www.youtube.com/watch?v=TNoZRh1VjLo

and the fs110 (1.2hp, 31.4cc) in the boat... not far off from the stock exhaust...

https://www.youtube.com/watch?v=OoCY6XKsnsI

Bogie I missed the part about it being 4 stroke lol. That explains the low hp numbers.

But here ya go, a complete RTR 29cc small block including a 900 series carburetor. No tax and free shipping, and all ya gotta buy is an air filter and pipe. More than double your current hp and 1/3 the weight. Can't beat that.

need a big ass prop or a ton of pitch to take advantage of the 4 stroke torque.

like a 78mm 1.7 pitch, which was too much prop, or the 72mm 1.4p 3 blade? Loike that? LOL

i have had my eye on some water cooled ones off ebay, like this one...gotta add clutch, pipe etc... but... not a bad little motor....
https://www.ebay.com/itm/29CC-Gasoli...l/193172430235

https://i.ebayimg.com/images/g/MMoAA...sg/s-l1600.jpg

then theres this one, no clutch, but it has the collet to be direct drive...and comes with a pipe....

https://www.ebay.com/itm/Chung-Yang-...oAAOSwA89d~Uz2