running a different head/barrel on a 2stroke...

[hmmmnz]

hi guys, well i have almost given up trying to find a barrel to fit my buggered kh125 barrel,
i have been reading about barrel conversions on vespas which seems like a fairly cool way of getting some extra hp out of an old air cooled scoot

my only hesitancy of doing something like this to my wee bike is that mine is currently a rotary valve engine, and as much as i loathe to convert it away from that as i really like the rotary valve system,

there are quite a few smokeys out there that run the same 50.6 stroke as my wee beast including the rg125 and 150s and rgv250 the kx125 rs125 the cagiva 125 range,
any of which i wouldnt have too much trouble getting a new barrel reeds and piston for, also i'd have to convert to 12v and run the donor bike cdi and power valves,
what do ya reckon
____________________
the humans are dead
I kick arse for the lord
Wiring Diagrams BIDNIP it bitches

[Kickstart]

Hi

To be honest I suspect it would be a pig of a job. Not sure which barrel would fit with close enough cylinder stud spacing to be modified, but suspect you would land up needing the carb and exhaust.

Power valve and the like is easy to do without (just get a barrel from an engine old enough not to have a power valve), and the same for a radiator (just get an air cooled barrel, eg Cagiva Roadster).

Why do you need a new barrel?

All the best

Keith
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Traxpics, track day and racing photographs - Bimota Forum - Bike performance / thrust graphs for choosing gearing

[400bandit]

I'm pretty sure that you wouldn't want to pay this much for one but you never know

https://www.cmsnl.com/kawasaki-1983-l1-kh125_model12345/partslist/1B.html

All the best,

Joe
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Current Bikes 650 Honda Bros, VTR1000 Firestorm // Past Bikes: Sachs Madass 50/110cc - Bandit 400 - FZR750
(+ a XS650 in lots of pieces in my garage and other places...)

[400bandit]

I've just had a thought, I'm not too clever when it comes to engine re builds and I have never touched a 2-smoke (yet).

Would it not be possible to bore the cylinder to accept a sleeve?

Joe
____________________
Current Bikes 650 Honda Bros, VTR1000 Firestorm // Past Bikes: Sachs Madass 50/110cc - Bandit 400 - FZR750
(+ a XS650 in lots of pieces in my garage and other places...)

[chillpill]

i read a random thread on a german 2stroke tuning forum where a guy put a crosser barrel on a moped engine . he removed the cylinder studs and just modded an adaptor plate onto the crankcases. ill see if i can look up the thread for you

[----]

Logan,theres a kh125 being broke on ebay:
Ebay link(shortened)

Any good?
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DRZ-400sm

[hmmmnz]

[hmmmnz]

[kat250]

The ar125 motor is a reed/rotary combo thing so it still takes in from the end of the crank.
____________________
in the famous word of jimmy pop "would you F*ck me for blow"
In the words of banditshigh "would you blow me to f*ck"

[Kickstart]

Hi

There are places that will make up and insert a slieve. PJ Engineering in the UK for example.

While that would be about £100, and I very much doubt you could manage to fit an alternative top end (including getting the bits) for less.

The normal (1980s) AR engine is water cooled, and also an odd setup with a disk valve and reed valves, which might make the intake timing a bit screwy for your purposes.

All the best

Keith
____________________
Traxpics, track day and racing photographs - Bimota Forum - Bike performance / thrust graphs for choosing gearing

[hmmmnz]

mmm well that rules out the ar125, i thought something looked a bit odd when i was looking at it.

on the other hand i do have 2 rg150 engines in various states of disrepair
im picking that up this weekend from home, so ill have a measure about and see if its at all possible to make fit..
if they can do it to damn vespas i sure im good enough to do it to a kh



https://www.scooterhelp.com/moto.barrels/moto.vespa3.lg.jpghttps://www.scooterhelp.com/moto.barrels/moto.vespa2.lg.jpg
https://www.scooterhelp.com/moto.barrels/moto.vespa1.lg.jpg
____________________
the humans are dead
I kick arse for the lord
Wiring Diagrams BIDNIP it bitches

[Blue_SV650S]

How do you propose sealing off the rotary valve?

As kickstart said, a re-line is the simplest solution.
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The purpose of life is to fight maturity.

[BenR]

Why not just another engine in the bike?
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Current bikes: suzuki RG125UN wolf. Yamaha MT-07

[Pete.]

What about using the RG150 piston and boring the stock Kh barrel to accept it?
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a.k.a 'Geri'

132.9mph off and walked away. Gear is good, gear is good, gear is very very good

[baldy]

[hmmmnz]

the liner is only so thick, going from a 56mm bore to 61mm there would be no liner left

[Kickstart]

[hmmmnz]

yeah there are, but the price is about $600 to get one made and then the price of a standard piston and rings on top of that.
considering i paid $100 for the whole bike im sort of loathe to pay that, as i could buy another rotary valve bike for that,
im being a bit of a cheap bastard i know and i dare say ill end up doing that in the end, but i have some rg150 engines and if its possible with out huge amounts of effort then ill give it a go, if not then ill fork out silly amounts of money on a bike thats not worth it
____________________
the humans are dead
I kick arse for the lord
Wiring Diagrams BIDNIP it bitches