Custom Frame with a Beasty Engine

Hey All!

I'm looking at building a custom frame and putting a beasty 2-stroke engine in it. Something that will ideally get me in the range of 15-20 hp, while still being twist-and-go. I know I have seen this question kicked around a few times before, and that the KT100 engine has been suggested, but I just called Comet Kart Racing and they pretty thoroughly shut down the idea - I guess the KT100 engine uses a clutch that is meant for super high RPM, so it will burn out like crazy with regular riding, AND it won't work with a torque converter.

SO it's back to the drawing board for engine ideas. I'd really love something that can also utilize a CTV - ideally dual variated.

I was thinking at one point of doing an AV10 engine (and MAYBE figuring out how to dual-variate it), but would love something that can generate even more horsepower. I'd also love to keep the budget SOMEWHAT low - under $800 for the engine / ignition / carb if at all possible - though that is a lower priority than just getting ideas.

Thanks all! I know it's an off-the-wall question, but I feel like somebody has to have done this before - the key challenge at this point has been finding an engine that doesn't already have a transmission (so I can make it CTV).

Re: Custom Frame with a Beasty Engine

kt100 is actually a pretty good idea, you'd just have to figure out how to set up a cvt on the crankshaft

what about taking a jog 90/ minarelli horizontal and just cutting off the swingarm part?

i've had an idea for years to cut the whole swingarm part out of a scooter motor and put a sprocket on the axle shaft like a jackshaft.

the only other thing i can think of is a 140cc 2t snowblower engine, there was a guy on here a few years ago that put on on a puch magnum and had pretty good results. they aren't power monsters but they have enough displacement that they don't have to be.

Re: Custom Frame with a Beasty Engine

Oh man those are all great ideas. I've been trying to hunt down aftermarket CVT's to no avail.

Are you thinking of using the minarelli CVT on the KT100? Or just a whole Minarelli or Jog engine?

I was reading this post and it sounds like the Torque Converter (are those the same as CVT?) has been done:

https://www.reddit.com/r/Karting/comments/1zqtyz/anyone_know_about_putting_a_cvt_on_a_kt_100_or/

Those snowblowers look like they make about 5hp, which is just silly.

Re: Custom Frame with a Beasty Engine

Ooh there's also the Yamaha BWS 100

https://advrider.com/f/threads/100cc-two-stroke-engines.1250440/

Some ideas here

Re: Custom Frame with a Beasty Engine

1977 sells crate derbi sends engines for $750. I would go that route personally.

Re: Custom Frame with a Beasty Engine

yeah a 'torque converter' is the same thing as a cvt but set up for go kart/ lawnmower engine type applications

those snowblowers make 5 hp at like 3500 rpm, the porting on them is garbage and the carbs are tiny. put a vm22 on there and open up the exhaust and i bet they'd rip, but they are just really shitty compared to a powersports engine.

i think the kt100 is a great idea, there are a bunch of other engines in that class from IAME, yamaha, comet, etc. they have them set up for all kinds of racing classes so i'm sure some are built to be all out rippers, but there are probably classes that run more conservative setups too. i've seen them for sale on craigslist cheap needing rebuilt and been tempted to grab one.

BWS/ booster/ jog/ zuma/ minarelli horizontal are all the same engine. biggest problem for stuffing it in a custom frame is it is super wide because its designed for the transmission to hang way off the side.

there is also that huge 50mm parmakit av10, still limited to moped sized stroke and moped variators and stuff so short of breaking things a lot you're in the <10 hp range.

Re: Custom Frame with a Beasty Engine

Ahhh awesome. KT100 seems like the best option and the best price, as long as I can find a torque converter for it. My thought was to get it so the drive was on the right side, use a jack shaft from the back of the torque converter to the left side - that way I can keep the engine centered.

Re: Custom Frame with a Beasty Engine

The derbi engine is pretty sweet - thoughts on how it compares to the AV10?

Re: Custom Frame with a Beasty Engine

Stock the senda makes around 8 h.p., they top out in the mid-high 50s. I built one for a friend with a 70cc metrakit street performance cylinder and pipe, stock stroke and a 26 vhst carb kit that blew the doors off of any moped. Speedo was reading over 70, but I'm gonna say high 60s is more appropriate. I never did clock or gps it though.

Re: Custom Frame with a Beasty Engine

Also, what kind of transmission is on the Derbi engine? 8hp is low for what I'm going for, but it looks like people are able to kit it to 19hp. It's definitely at the top of the price range, and will take a bunch more stuff on top of it if I wanted to go that route, but I could always run stock for now and upgrade it alter.

KT100 still appeals the most, but will take a lot of figuring.

Re: Custom Frame with a Beasty Engine

Dirty30 Dillon /

Derbi engine is 6speed manual clutch.

Hard to tell if that's the EBE050 or the AM6 Motor as I don't really recall the differences.

You're looking to spend less than $800 on a 15-20 hp bike, and that just might be plain difficult

Re: Custom Frame with a Beasty Engine

Ahh totally makes sense!

I'd rather stick with CVT as opposed to manual clutch, but the Derbi is a super good option. Definitely seems like the most easily applicable, and has huge amount of power.

Re: Custom Frame with a Beasty Engine

I think its the ebe, says it came on pre 2006 Derbi. I was flirting with the idea of swapping one into my dt50 before I sold it.

Re: Custom Frame with a Beasty Engine

I'm thinking something along the lines of a Van Tech frame. Not sure for wheelbase and rake/trail.

Re: Custom Frame with a Beasty Engine

I just dont think you're going to end up with a streetable bike this way. Also karts arent meant to be ridden more than a few laps at a time, so I think longevity is a problem too. I would imagine a nominal amount of reliability is a factor you're looking for. Why do you want an automatic?

Re: Custom Frame with a Beasty Engine

Re: Custom Frame with a Beasty Engine

Oof. Good to know! Definitely want reliability and streetable. I want automatic partially because my wife (Heidi) doesn't know how to use the clutch and all that, and I'd love her to be able to ride it as well. Plus, I really enjoy the one-handed-riding aspect of mopeds.

Re: Custom Frame with a Beasty Engine

> Graham Motzing Wrote:

> -------------------------------------------------------

>

> what about taking a jog 90/ minarelli horizontal and just cutting off

> the swingarm part?

>

> i've had an idea for years to cut the whole swingarm part out of a

> scooter motor and put a sprocket on the axle shaft like a jackshaft.

>

Sounds like a dumb idea to me.

05959FCA-2694-42F8-A813-0708C5A97E58.jpeg

Re: Custom Frame with a Beasty Engine

No permission to access thread! I'll make an account.

Re: Custom Frame with a Beasty Engine

> Thomas TPRF Wrote:

> -------------------------------------------------------

> Sounds like a dumb idea to me.

> >

ho ho ho ho ho

more details plz? i've been talking about doing this for years... maybe someday when i run out of projects.

Re: Custom Frame with a Beasty Engine

Dirty30 Dillon /

My biggest question is what are you looking to use this for?

Re: Custom Frame with a Beasty Engine

Daily riding - some longer (island riding) trips but nothing insane - but mostly riding around Seattle. Would love to be able to keep up with my friend on the 80's Honda CH150, and figured that since I'm building this anyway, would love to be able to really rip (as Daniel said, blow the doors off of mopeds).

Not looking for a race bike or anything like that. I'm comfortable working on the engine (owned a 75cc AV10 that seemed to rattle something off every week), but would honestly love to keep that to a minimum!

Daniel nailed it with his point about the daily driver. If this engine needs to be rebuilt every couple months if I ride it to/from work and bar-hopping in the summer, that's not appealing.

Honestly I'd just get a freaking old Yamaha RD if I weren't so interested in finding an automatic!

Re: Custom Frame with a Beasty Engine

Snowmobile engine. Lotsa power, comes with a cvt. Lol but then your looking at a full size bike

Re: Custom Frame with a Beasty Engine

I am now looking for a <200cc snowmobile engine, lol

Re: Custom Frame with a Beasty Engine

Piaggio LT50 or Kymco People 50, both 15” wheel, 50cc 2 strokes with upgrade potential. They’re both ugly, and I like scooters, but either engine might be a good starting point for something custom.

Re: Custom Frame with a Beasty Engine

Radne raket 120.

Tiny package, pull start, fast as hell

14-15hp.

Re: Custom Frame with a Beasty Engine

Oh whaaaaaaat that's amazing!

Re: Custom Frame with a Beasty Engine

Thoughts on the Predator engine? I know people have said it's incredibly underpowered for what it is, but I'm seeing kits for it that apparently bump it up to 15+hp

Also saw this:

https://www.ebay.com/itm/Clone-Predator-Engine-212cc-kart-mini-bike-drift-trike-motor/273704906481?hash=item3fba156ef1:g:lysAAOSwdgxcBHVI

Re: Custom Frame with a Beasty Engine

No, those things suck hard. I don't like 4 strokes. But maybe you should go with a lifan semi auto. Sounds like the two strokey bits isn't as important to you as it being an automatic.

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