Changing the valve seals- anything else I should do while in there?

I have the head pulled for the wiseco kit I will be installing. I figure it's a good idea to install the valve seals that came with my gasket kit, as the old ones are probably original and 20+ years old. So I have pulled the valves, and will be sticking the head in the decarb tank at work.

The valves all look good so far, and I didn't have any problems that I know of before removal. Once removed, I poured solvent in all intake/exhaust ports and inspected the valves, and I did not note any leakage. I will inspected the valves closer when I clean them in the parts cleaner, but for now, I hadn't noticed any problem spots.

I had figured I would lap them for good measure, and reinstal everything with the new valve seals in place. A friend of mine said that I should not need to lap them though, if everything was fine to begin with, as they are already "lapped in". Anyone have any opinions on that?

Also, is their anything else I should check closely? I don't want to spend money for no reason, but now that I'm in here, it's the time! The bike has around 13K indicated miles on it.

Thanks alot!

i prolly would have done a leakdown test before removing head...too late now though. may wanna take your head to a shop to check the guides. not that big a deal for a shop to press in a new set. prolly money well spent.

delkron97 wrote:

i prolly would have done a leakdown test before removing head...too late now though. may wanna take your head to a shop to check the guides. not that big a deal for a shop to press in a new set. prolly money well spent.

If you change the valve guides, then you have to remachine the seats.

Jay

yea i probably should have.. but I didnt even plan on doing the big bore kit when I pulled the head.. Just kinda felt like doing it, heh. I had done a compression test about half a year before and everything was fine at that point though. Granted things can change, but I believe the biggest thing would have been rings, if anything. If a valve was leaking, I'm sure I could see the visible signs.

So say I keep all the valve guides and the valves all seem fine.. should I lap them for good measure or no?

A hand lapping couldn't hurt if you have the time.

I would also suggest hand lapping. I picked up some lapping compound from NORWALK POWER EQUIPMENT COMPANY for 16.95 shipped. It has 120/220 grit package part number 9355 along with a manual valve lapping tool. I picked up a suction cup lapping tool from EBay 7.25 shipped. I also went on step further and used bluing to check the contact for valve face and seal. It takes about an hour to perform the task and well worth the trouble to ensure valve sealing. Art

Trav, one cautionary note. If you get the one-piece cometic headgasket from Wiseco make sure you don't use the center o-ring around the camchain tunnel that was there with the 2 piece headgasket. You could end up with a leak on the center 2 cylinders.

Thanks, guys. I think I will lap them. I definitely have the time, heh.

DesertWizard.. not quite sure what you are talking about. The head gasket that was installed on my bike is very similar to the one that came with my gasket kit (which I won't use with the new pistons) and also the larger bore wiseco gasket. The only differences would be color and such.. otherwise they seem fairly the same. Maybe this is something my model engine does not have, that other KZ's may?

Trav, sorry for some reason I thought you were talking about a KZ1000. In the words of the late Gilda Radner from Saturday Night Live "never mind"