the mystery debris in the motor. (kawi 120) wtf

[m in sc]

thats true. I was going to buy a press but luckily I get to use a friends at work if i need one. its total over kill . but that makes it just right.

the spec is 0.0012" to 0.004, the closest i could get the runout is .002. i'll take it.

i verified the adjustments at work today on the bigger lathe, made setting up the dial indicators easier.

[Striker1423]

Turns lathe on...

[m in sc]

....

[m in sc]

got the lower end together last night, pretty simple as expected.  check out this rotary disc I got on ebay though. I bought nos stocker but also this aluminum one which must be a period high performance one. 🤔  I prob won't run that one but I'm going to def check some intake duration numbers. 

[m in sc]

and the follow up. took the test ride today, did really well. also, note the head nuts. these are M8 nuts for the exhaust on my XR150L, ordered a bunch from partzilla for this, and also should be good for rd chambers as well. 12mm wrench flats and allen key end.  while i was in there put on a new RK chain, and did a few other small things not worth mentioning but just small detail stuff. also, i hate the ignition on this thing, the points behind the drum suck. so time consuming to set. 

bike ran great, plug looks right, motor is dead stock except for a 1mm over bore & some tiny port cleanup (which has been there for 10 years). checked compression after the test run, right at 142 PSI.





no shiny bits on the plug. yeah! (no not a plug chop)

[Kawtriplefreak]

  

[kpke]

Very nice. What a cool little bike. Looks like fun.

[Dvsrd]

I totally agree. A very cool model. The engine looks very similar to the KH/KE 100 models sold in Norway into the mid 80s. I feel a little sceptical about an alloy rotary valve. Aluminum on aluminum does not sound like a happy, friction less "marriage". I believe the composite rotary valves on other Kawasaki models had issues as well?

[SoCal250]

Don't know which is more surprising, that the bike is already all back together and ripping around or that price for Premium!

Looks great Mark! Small cc FTW!

[m in sc]

i put in the new NOS fiber one. the aluminum one was just a 'what the hell, i'll get it' thing. it added like 27? degrees on intake duration, it was crazy. most in the beginning of the event, and added like 3 or 4 on the back side of it.  lol. the original disc was in good shape, but put in the replacement just because it was cheap.

its very related to the KH/KE motor. ign rotor swaps with them, as does a very few small parts. id love to get a CD unit for one and retrofit this, but they are hard to find.  the actual displacement is 115cc.

thanks Russ. it wasn't hard to repair, just waiting on parts and i have not much else going on in the garage right now since the KZ is pretty much done.

 

[Striker1423]

You could always mod that aluminum one to run at whatever duration you want by removing material.