1974 Kawasaki KS 125

[74saki]

I am looking for a new piston and ring set for my bike, but am having a hard time to find one. I want to know if I could use a 1974 KX 125 piston & ring set. Or could I use a F6 piston?

 

[Colorado]

I was just reading a site the other day when I did a search for motorcycle pistons. The owner of the site was talking about using any piston with the correct diameter wrist pin for hard to find bikes. "Something to remember, if you are working on an old bike and are having trouble finding a piston. As long as the wrist pin diameter is the same and you can bore the cyl to fit it. Almost any piston will work. You might have to cut the piston skirt down or drill big ports in it. You might have to grind the piston head to fit the combustion chamber or grind inside the skirt to make it the right weight, but with some imagination you can make it fit and it will work. " Here's the site: http://www.dansmc.com/pistons.htm

Sounds like it might be a lot of work, but if that's the only option ...

I had a new KS 125 back in the '70's. Used to ride it in the dirt and aslo commute into Chicago on the expressways when my car was down (which was pretty scary ---- Chicago drivers are fast and agressive).

 

[74saki]

ok, cool thanks

 

[Succubus]

There are two ks125 pistons on the Bay of E right now. One standard, one .40 o/s. Do a search on "ks125 piston" and they should come up. Hope this helps.

 

[Colorado]

Since the '74 KS125 came up, I think it was probably the best of the true vintage dual purpose 125s. Mine weighed less than my friend's '73 (or '74 -- it was blue) DT125 Yamaha (which had an electric start?!?), had a 21" front wheel, the lower, thinner saddle of the last of the dual shocks, and a six speed tranny. If I remember right, the pegs were even serated instead of ribbed rubber.

It wasn't an Elsinore, but would beat the Honda Elsinore wannabe dual purpose, borrowing a lot from the Elsinore technology. A guy in the neighborhood who raced a sponsored Penton, then an Elsinore with all the tricks, thought it was impressive (back then) compared to the Yamaha (the Suzuki TS wasn't much in those days, and even the TM was behind the curve). The KS was almost the flagship frame geometry that later became the first KX125 --- which then proved itself to be behind the curve regarding the new suspension. The YZ and RM rewrote history, followed by the CR.

But the KS had it's moment, and I WAS THERE.

 

[2stroke]

Kaw enduros you say, why thats my department.

Anyhow,

the KS125 shared identical bore and stroke with the KD and KE 125s so those pistons will also work.
The KX125 piston will also work, as the KX125 also had the same bore and stroke...the only thing with the KX model pistons was that the piston clearance was just a shade less...a performance issue no doubt. But, it would sure work, especially if you get the KX piston and take it to a shop and have it bored to fit.


Click this: They say they have a standard KS piston available

http://houseofmotorcycles.bikebandi...79139~model_dept_name~KS125(KS125)US.asp#stay

 

[74saki]

Thanks for the help guys, but I started to split the cases yesterday because of about 1/8" of connecting rod play. I also notoced that the rotary valve was beat up, and the motor started making a grinding noise from inside when I was turning it over by hand and then it stopped all together and figured it was going to cost me more to fix the motor so I am looking for another 125 motor to fit in the bike. I have the option of buying a '89 KX 125 motor w/ all electrics and radiators for $100 or the entire bike for $250. The motor runs, but the only thing that the bikes needs to be fully functional are brake parts. So how difficult would it be to retrofit the 89 KX motor into the 74 KS frame?

 

[Colorado]

Thanks for the help guys, but I started to split the cases yesterday because of about 1/8" of connecting rod play. I also notoced that the rotary valve was beat up, and the motor started making a grinding noise from inside when I was turning it over by hand and then it stopped all together and figured it was going to cost me more to fix the motor so I am looking for another 125 motor to fit in the bike. I have the option of buying a '89 KX 125 motor w/ all electrics and radiators for $100 or the entire bike for $250. The motor runs, but the only thing that the bikes needs to be fully functional are brake parts. So how difficult would it be to retrofit the 89 KX motor into the 74 KS frame?

Why would you want to? I loved my '74 KS in '75, but I'd take the '89 suspension in '05'.

 

[74saki]

I found a bottom end on the site by the bay that I will probably pick up, so that I could keep my KS and make it run by the Spring.

 

[zoommx]

Just a note to consider if you're trying a non ks piston, make sure the ring end locations arent lining up with a port. I think locator pins can be re-located with a little patient machining.