KDXRIDER.NET

Welcome to “Yet another rebuild thread”

The plaintiff: kdxsully

The defendant:



State your case: Are you chinese???



What does the jury think??

Guess we’re gonna be rolling up our sleeves!

What do you guys think, bore this out or buy a virgin cylinder and send it to be plated??

Spent some time tugging my rod. Felt tight. It was difficult to get even the slightest bit of up and down play. Side to side play seems excessive. Rod doesn’t scrape the crank though.

I'd send it to a motorcycle shop for boring and honing and go with the oversize.

The sleeve does not look 100% lined up. What does it look like to you?

Which bike / engine is this??

KDXGarage wrote: 10:42 pm Jun 19 2019 I'd send it to a motorcycle shop for boring and honing and go with the oversize.

The sleeve does not look 100% lined up. What does it look like to you?

Which bike / engine is this??

This is a 1984 motor.

1988 crankshaft side to side play standard is .5mm, service limit is .7mm. I’m at .55mm, so we’re okay in bottom.

To address the sleeve, I’d have to say this sleeve was probably made for 86-88, because there’s two small ports just above each side of the exhaust port that I’m assuming would be for the power valve. I’ve never seen a powervalver cylinder so I wouldn’t know for sure. All the ports line up well except the exhaust port. It looks like some trimming was done. Not too bad. One of the transfer ports has some sharp edges on the intake side (unrelated to the sleeve). Should these be cleaned up before I go with an oversized piston?? Can I even get an oversized piston to fit this bike? Being that all oversized pistons are 86 and up, I’m assuming. I was gonna put a wossner in this for the higher chance of not needing any modification.

Hmm! With it being the '84, that is bad on the piston.

How do the piston pins align with that sleeve?

A motorcycle shop may be able to handle that sleeve better than a general machine shop.

KDXGarage wrote: 01:30 am Jun 20 2019 Hmm! With it being the '84, that is bad on the piston.

How do the piston pins align with that sleeve?

A motorcycle shop may be able to handle that sleeve better than a general machine shop.

I’m looking into getting an unsleeved cylinder.

You mean the ring pins right? I’ll just take a photo later

While I’m here, on the cylinder there’s this little Japan-esque symbol with a “- 1”

What does that mean? I’m looking at a cylinder with a (symbol) - 2. What’s different about them? I think it’s an 85, I’ll have to double check

Sorry, yes. Ring pins

I am not sure on the numbers

I can get actual angles and stuff at work tomorrow. They have a digital protractor. I also tried to do my best to measure from the bottom on the pin hole to the bottom of the skirt. I saw somewhere a guy had to cut 3mm off of his skirt, so I figured having that measurement could be helpful. I can measure to the crown later too, that’s probably a better measurement anyways (don’t know why I did it this way, that was awkward). That thick line on the piston is the exhaust arrow. ‘B’ is the bottom ring, ‘T’ is top.

Also, these aren't super exact. I'd have to rig up the piston on te crank and slide the cylinder over to get a perfect one. But these sre pretty dsng close.

Also, here’s that symbol I mentioned. No idea what this means, and if it is significant. The cylinder I’m looking at is symbol - 2. Anybody??

I don't really know squat about anything Japanese,
but,
On castings with the European and US stuff i work on,
There's all kinds of numbers and marks on complex castings that have no bearing whatsoever on what part it is or the part number..

Mold makers and foundry guys will keep track of part lots, metallurgy, who made it, time/date, all kinds of stuff.

Clatter wrote: 06:29 pm Jul 08 2019 I don't really know squat about anything Japanese,
but,
On castings with the European and US stuff i work on,
There's all kinds of numbers and marks on complex castings that have no bearing whatsoever on what part it is or the part number..

Mold makers and foundry guys will keep track of part lots, metallurgy, who made it, time/date, all kinds of stuff.

That’s what I was thinking. Maybe it’s a mold identifier? Maybe it correlates to the bore size. My symbol-2 is a “B” cylinder, symbol-1 is an “A”

Some of you already know, I bought a virgin '85 cylinder on feeBay. I sent it off to PowerSeal for replating. I did do some piston tests with it before sending it off.





The 86-06 Wossner piston does indeed fit, and the ring grooves are located higher on the piston than the others. I marked the pin locations and the one with the 'B' is the bottom pin. Thanks, KDXGeoff.




These aren't perfect because they were in my lap. Basically, the bottom of the Wossner grooves are lined up with the top of the grooves on the Chinese piston.

Disclaimer to 83-85 owners. Try a Wossner, but check everything. Pretend I'm lying first.

Thanks for the pictures.

Thanks again to KDX Geoff

Got the cylinder back from PowerSeal. Beautiful. I’m a bit disappointed in the chamfering. I’d correct it, but this being my first time I REALLY don’t wanna damage it.
Hmm, something isn’t quite right...

Looks great to me! What am a I missing, no paint?

KDXGarage wrote: 04:57 pm Aug 03 2019 Looks great to me! What am a I missing, no paint?

It’s supposed to be black!!

I bead-blasted all my ‘83-85’s. I like the look.

But, yeah, if you want it black, they messed up.

lucy wrote: 07:12 pm Aug 03 2019 I bead-blasted all my ‘83-85’s. I like the look.

But, yeah, if you want it black, they messed up.

What’s it look like?

Well, at least I know where the stickers go.