just curious...

[Gouldian]

I've seen a bunch of post asking somthing like; "I want to put this massive bike engine on my one wheel drive yerf dog. How much duct tape do I need?" Or somthing to that effect. I wonder, what would be an appropriate sized engine to swap onto a small buggy? With gusseting and extra support, could I use a 4 stroke 250? 350? Obviously using a 600 ninja engine would take time and money I don't have. But could somthing sane be swapped in without recruiting a NASA engineer?
Side note... have any of the 600-1000cc guys gotten farther than than tear down?

 

[mckutzy]

Yes, but only a few... And the one I can remember, the dude got it impounded a couple of times by the 5-0. In the end I think he broke the motor or something. The link I don't have... but you will have to look it up or wait till he or someone remembers.

 

[chancer]

Most of those guys show up here get laughed out of town and never come back to prove us wrong. I think to answer your question a good size moter would be like a quad engine around 80 to 200cc's, the difference is they have the tranny built in, compared to our industrial type engines with a cent. clutch.

 

[Gouldian]

...the difference is they have the tranny built in, compared to our industrial type engines with a cent. clutch.

pretty much my reason for wanting one.

Would a factory kart with somthing in the 420cc range take the stress of say, a 250 rebel drivetrain? Some mods are obvious, gussets, brakes, ect.. plus you would have to make it fit and function.

 

[landuse]

Yes, but only a few... And the one I can remember, the dude got it impounded a couple of times by the 5-0. In the end I think he broke the motor or something. The link I don't have... but you will have to look it up or wait till he or someone remembers.

The kart was called the green goblin. A search would probably pick it up

 

[KartFab]

Some performance golf carts, and mini buggies use the comet 780 CVT with a v-twin industrial type engine (eg Briggs vanguard, Honda gx 610/gx620/GX670, and predator v-twin.

 

[Gouldian]

My reasoning is that a bigger tc can cost hundreds of dollars. Plus an engine. I found a crashed 250 honda for 300 bucks. Thats an engine and transmission. Plus any other parts that are salvageable. (Brake system, lights, switch gear)

 

[itsid]

I think if it's reasonable power you're talking about it shouldn't be a problem (apart from fabbing the mounts)

But without knowing which kind of kart ("small buggy" can be anything really )
it's impossible to judge what's considered sane and what's not.

But 250cc maybe 300cc... something along 30-40 horses...
that should be manageable with about any adult sized mini buggy;
as long as you keep an eye on brakes, axles and bearings as well as gearing to handle additional power; and rather dial towards safety than cost saving...
that's not out of reach at all.

'sid

 

[OzFab]

250cc is very reasonable, as long as the frame/subframe is strengthened to suit; there's a massive difference in hp between a 420cc industrial engine & a 250cc motorbike engine...

IIWM, get the bike before someone else does; worst case, you can part it out to recoup costs if it's not suitable; in the meantime, do some research on the bike; find out the hp rating & other related/useful specs

Oh, BTW, I moved this thread because it's more appropriate in the general discussion section at this point...

 

[Gouldian]

Thanks guys. I always get good answers here. I found an adult buggy locally. Going to look at it when I get home time. it looks like a suburu engine. Engine mounted to a swingarm. Double a arm front suspension. Not sure the bike engine would like being rattled around stuck to the rear. But, nothing is really solid until I get there. Kinda hard to inspect project fodder when you're 2,000 miles from home.

 

[crazykart]

I don't think it would mind all that much being rattled around, stuck in the rear.

 

[yellowbeard]

doing it to mine, kaw. ninja 250r.

 

[yellowbeard]

working on jackshaft now.

 

[Gouldian]

That's a fancy lookin' motor mount ya got there.. what kart did you start with? it looks an awful lot like the one I have here.

 

[yellowbeard]

used angle iron for the mounts. check out my update.

---------- Post added at 03:50 PM ---------- Previous post was at 03:46 PM ----------

I think it was a yerf 3202. but not sure

 

[yellowbeard]

Ninja 250R

 

[Gouldian]

bit of an update, and possibly the start of a build. the Honda rebel was gone when I got in, but I picked up a 1971 Honda cb360t. a little bigger than I was looking for, but should be fine. I got to thinkin' about using a tc from a snowmobile between the trans and the axle. not for the power or speed, but for the ability to be in gear and come to a full stop. from what I've found, the engine turns about 8,000 rpm. I have not found gear ratios yet, but was told 5th and 6th gear are overdrive. how fast could I safely spin a tc before it turned to shrapnel? and how do you kickstart an engine mounted behind you?

 

[Gouldian]

After much scouring of the interweb, I have found...not much. The engine was rated at 34hp@9,000 rpm. I've seen conflicting specs as to transmission ratios, but more of them say that 6th gear is 1:1. The snowmobile tc I have would hold up to the rpm(I think) but im not sure about the power/torque. It looks like the one I picked up is electric start as well as kick, so thats a plus.

So after the holidays, I'll see if I can get it to start and go from there. The powertrain is larger than I thought it would be, so I'm going to have to rethink my plan on a chassis.

 

[number9]

I would looooooove to have the engine off one of my YZ250's on a dirt racing chassis

...

 

[J_Walker]

After much scouring of the interweb, I have found...not much. The engine was rated at 34hp@9,000 rpm. I've seen conflicting specs as to transmission ratios, but more of them say that 6th gear is 1:1. The snowmobile tc I have would hold up to the rpm(I think) but im not sure about the power/torque. It looks like the one I picked up is electric start as well as kick, so thats a plus.

So after the holidays, I'll see if I can get it to start and go from there. The powertrain is larger than I thought it would be, so I'm going to have to rethink my plan on a chassis.

the thing has a transmission. why are you using a torque converter?

Determine the size drive tires you're gonna use. then work out the numbers from the bikes original tire size and final gearing. and work off those original numbers to get a close match, a little extra torque is gonna be better then the exact match tho. for any engine the general rule of thumb is never load it more then twice the amount of the bike. so if you have a 400lb bike. with the engines default gearing, you can load it to 800lbs. After that 800, you want to gear it towards having more torque. bigger rear sprocket in this case.

Nothing wrong with using motorcycle engines, the hardest part [assuming you have a running bike] is fabbing engine mounts. and finding a sprocket with the right amount of teeth for let's say a one inch axle with a 420 chain. to fit your gearing.

Besides that the only problems that could rise depends on how tall your original kart is. a 52 tooth 420 chain isn't exactly a small sprocket.