When putting the exaust valves in a 2001 ZR 500 can they be put in upside down? Which way is up? Thank You!

Yes they can. Be careful. I believe these are the spade type. Don't put them in upside down or I believe damage could occur. I do believe that the piston could hit this if it was upside down.
If this is the spade type you have to look at both sides and see which side has the bigger taper to it. This side goes down. It makes for more area above the piston. This is kinda hard to explain. Maybe someone else can do it better or has a pic of one.
Seadoo made there's easy. They actually put UP on one side of the spade. But once you do it, you know which way they go.

Here's an article about cleaning some valves on an AC 800. There are some pretty good pics so hopefully you can tell which way they go from these. Hope it helps. Exhaust valves (http://www.off-road.com/snowmobile/info/howto/exhaustvalves/clean/katexhaustvalves.htm)

Originally posted by wizzells@Oct 23 2002, 05:14 PM
Here's an article about cleaning some valves on an AC 800. There are some pretty good pics so hopefully you can tell which way they go from these. Hope it helps. Exhaust valves (http://www.off-road.com/snowmobile/info/howto/exhaustvalves/clean/katexhaustvalves.htm)
That's a pretty good article. Except for the razor blade part. They tell you to try not to scratch the valve. I try to use a brush and carb cleaner. I don't wory too much about the port side. Too worried that I may knock a bunch of crap down the cylinder. If yours are really bad then I would do it but maybe have a shop vac handy.
Another note is that I hear on the Snopros, they have 3 positions instead of the normal two. I guess they have a mid position also.