Wossner Piston kits

[tengai]

So is there any local dealers on Vancouver Island that sell Wossner Piston kits for the 530 exc?

 

[broxy]

I bought a Vertex for a 530 from These chaps. Neither a Wossner nor BC, but Canadian,and quick shipping. The piston is doing a fantastic job going up and down, and making more power than the bike ever made before, which is strange since it is stock size and compression.

Braaaap

 

[tengai]

Thank you ,checked them out. Did you find when you replaced your old piston ,that the bore of the cylinder was still in stock tolerance to accept a new stock piston?

 

[broxy]

The bore was perfect, until a friend 'helped' and got all mashy and rolled an oil ring, gouging the cylinder. I took it to a plater in Calgary who charged me $40 for a hone. He could have charged me $300 for a replate, but he is a stand-up guy, and said no harm was done. Make sure you get a professional to hone it. Standard hones aren't right. Skylark in Calgary is an MX and ice racing legend, and great guy to deal with. He was featured in an article about Redbull Rocks and Logs in the latest TractionErag magazine, riding a home built electric bike in the event.

So yes, the bore was well within stock spec even after the incident. Nikisil is tough! The bike had always consumed very small amounts of oil, but never enough to warrant an overhaul. The big end developed a knock, so I ripped into it. When you lift the head, clean up the piston crown and you'll see what size your piston is. There are a few sizes based on the original bore/ plate specs.

Here you can see the original piston was 94.95mm, making it a B. A is 94.94mm.

 

[tengai]

The bore was perfect, until a friend 'helped' and got all mashy and rolled an oil ring, gouging the cylinder. I took it to a plater in Calgary who charged me $40 for a hone. He could have charged me $300 for a replate, but he is a stand-up guy, and said no harm was done. Make sure you get a professional to hone it. Standard hones aren't right. Skylark in Calgary is an MX and ice racing legend, and great guy to deal with. He was featured in an article about Redbull Rocks and Logs in the latest TractionErag magazine, riding a home built electric bike in the event.

So yes, the bore was well within stock spec even after the incident. Nikisil is tough! The bike had always consumed very small amounts of oil, but never enough to warrant an overhaul. The big end developed a knock, so I ripped into it. When you lift the head, clean up the piston crown and you'll see what size your piston is. There are a few sizes based on the original bore/ plate specs.

Here you can see the original piston was 94.95mm, making it a B. A is 94.94mm.

.
Good info,thank you. Mine is still stock after 325 hrs and over 10 k,and is actually still not burning oil and the valves holding spec but thinking I'm going to have to do a rebuild eventually. Thinking piston kit,new valve seals,upgraded pump gears and so on.

 

[broxy]

That's all I really did as well, other than the rod of course. There was only one bearing on the shift drum that was screwed, but that was sourced from a local bearing shop. I did mill the case for shared crankcase/ gearbox oil, which I will do to mine as well when the time comes.

 

[tengai]

What was your reason for sharing tranny and engine oil? I would think having them apart is a good thing.

 

[broxy]

Volume mostly. The engine only has 600cc on its own, now it shares the tranny oil for cooling and lubing. Shared is what the old RFS bikes were, the big twins, and the '12 and up bikes went back to shared gearbox/ clutch oil. Pretty much every major builder is doing the mod as well (covered extensively on KTMtalk and ADV), so it can't be a bad thing. It's nice to have that bit of security when you need it, and it eliminates the oil migration many have experienced (I haven't, but I installed all the updates on two bikes to avoid it).

 

[tengai]

Something to consider as well, is the aftermarket engine oil cooler ,which also adds extra oil volume. Will have to look up that joining of the tranny and engine oils .

 

[broxy]

There is an aftermarket oil cooler which replaces the stator cover, but I think its unnecessary. The merged sumps isn't really needed either, and in your case, may not be worth doing since everything you are doing doesn't require the cases to be split. You're bike is proof that you'd don't have to fix what ain't broke (325 hours is pretty good for a high strung dirt bike).