Extreme engine swapping, and hp talk

steffen707 · Post by **steffen707** » Tue Feb 03, 2009 12:10 pm

Okay, so i was looking at cr80s ans yz85s this morning, and some can be had for pretty cheap. I know it would take fab work to swap that into a scooter, but I like projects.

Online I read that most guys think the cr80 and yz85s have about 16-18hp stock! That's a TON more than the 4.6hp or whatever our 50cc scoots do.

Does anybody know what kinda hp numbers they get out of their 72cc bore kits with pipes, new carb, ect.? Is it close to 16-20hp?

I read somewhere that the polini corsa 72cc bore kit with their 12mm crank could do 24hp, but that sounded like extreme all out stuff.

I know these dirt bikes have gears and a clutch, yada yada, but if its a real cheap (fun and different) alternative to getting close to 20hp, thought i'd ask about it.

Post by **noiseguy** » Tue Feb 03, 2009 12:54 pm

Someone hooked up one of these engines on a scoot using a CNC-made rear wheel and drive assemble. Can it be done? Yes, but difficult. Really would be easier to do a moped with a real (non-integrated) swing arm.

steffen707 · Post by **steffen707** » Tue Feb 03, 2009 1:34 pm

which mopeds have real swing arms? Don't they all have integrated one piece engine/trans castings?

ALOW1 · Post by **ALOW1** » Tue Feb 03, 2009 2:00 pm

steffen707 wrote:which mopeds have real swing arms? Don't they all have integrated one piece engine/trans castings?

Moped, not scooter.

Dac · Post by **Dac** » Tue Feb 03, 2009 2:27 pm

Moped = Motor + Pedals.

such as....

[Puch, Tomos, Moby, there are tons and tons of different moped brands.}

I think Noiseguy is really onto something. 99% of all mopeds i have seen have chains and swing arms. Come to think of it the only moped i have seen that has a belt, pulleys and gears is a Vespa Ciao and those are farily rare anyway.

steffen707 · Post by **steffen707** » Tue Feb 03, 2009 4:01 pm

my bad. Problem I see with using the moped engine is that I've never heard of one being bigger than 50cc, and highly doubt would have power greater than a moded dio engine. Am I wrong?

steffen707 · Post by **steffen707** » Tue Feb 03, 2009 4:02 pm

Plus with the chain drive, these modepds only have one front and one rear gear right?

Kenny_McCormic · Post by **Kenny_McCormic** » Tue Feb 03, 2009 4:03 pm

Due to the way you ride a scooter the foot controls would be tricky. I would rather swap a yammy KT-100 in there. 15k+ rpm air cooled 2 stroke, sround 12 hp with a can muffler, much more with ex chamhber.

Post by **noiseguy** » Tue Feb 03, 2009 4:40 pm

steffen707 wrote:my bad. Problem I see with using the moped engine is that I've never heard of one being bigger than 50cc, and highly doubt would have power greater than a moded dio engine. Am I wrong?

No no, you're missing the point. If you want to swap in a motorcycle engine, start with a moped, not a scooter as the frame.

Guys at mopedarmy have swapped 110cc Lifan motors (Honda Cub / z50 clones) into mopeds for better all-around usability. There's no reason a KZ80 (or whatever) wouldn't fit into a moped. Here's a link to one done on a Streetmate. You'll also notice a poster, familiar to us all, talking off-topic st*t as usual, in here:

http://www.mopedarmy.com/forums/discuss ... 67/132767/

Best thing to swap into a scooter is another scooter motor.

steffen707 · Post by **steffen707** » Tue Feb 03, 2009 8:45 pm

noiseguy wrote:
steffen707 wrote:my bad. Problem I see with using the moped engine is that I've never heard of one being bigger than 50cc, and highly doubt would have power greater than a moded dio engine. Am I wrong?
No no, you're missing the point. If you want to swap in a motorcycle engine, start with a moped, not a scooter as the frame.

Guys at mopedarmy have swapped 110cc Lifan motors (Honda Cub / z50 clones) into mopeds for better all-around usability. There's no reason a KZ80 (or whatever) wouldn't fit into a moped. Here's a link to one done on a Streetmate. You'll also notice a poster, familiar to us all, talking off-topic st*t as usual, in here:

http://www.mopedarmy.com/forums/discuss ... 67/132767/

Best thing to swap into a scooter is another scooter motor.

OHHHH, i now understand your point now. Anybody know what kinda hp numbers they are pulling with their moded scooters?

Kenny_McCormic · Post by **Kenny_McCormic** » Tue Feb 03, 2009 8:57 pm

I highly doubt anybody has gotten into double digits with a air cooled kit, stock crank, and pump gas.

steffen707 · Post by **steffen707** » Tue Feb 03, 2009 9:11 pm

Kenny_McCormic wrote:I highly doubt anybody has gotten into double digits with a air cooled kit, stock crank, and pump gas.

Not even 10hp? That seems odd considering what some of these under 100cc production engines are capable of.

Post by **noiseguy** » Tue Feb 03, 2009 9:52 pm

A Ninja 250 will do 110 MPH, 36 HP. That's about your minimum engine size / tune for reliable power and a 4-stroke. Keep in mind wind resistance rises exponentially with speed.

Note that you can do considerably better with 2 stroke, but you lose wide powerband and reliability for street use.

Street scooters were not meant to go this fast... it's just a bad idea. I've done 100 on large street bikes; you literally couldn't pay me enough to go that fast on a 10" wheel scooter.

steffen707 · Post by **steffen707** » Tue Feb 03, 2009 10:05 pm

Ehhh, I don't wanna go 100mph on my scooter. Just wanna accelerate quickly to like 50mph.

The 08 ninja 250 is the motorcycle I wanna buy. Looks sweet, low cost, great starter bike.

Dac · Post by **Dac** » Tue Feb 03, 2009 10:26 pm

steffen707 wrote:Ehhh, I don't wanna go 100mph on my scooter. Just wanna accelerate quickly to like 50mph.

The 08 ninja 250 is the motorcycle I wanna buy. Looks sweet, low cost, great starter bike.

50mph with a quick launch? thats it?

dude your thinking way to big. A dio motor can do that easy. like 50mph is nothing for a dio.