Questionfor the future of my cylinder head

Pull the head of my newly acquired KZ750N1 spectre to do some cleanup inside, and in the process had one exhaust valve too tight. It measured .05mm clearance with a 2.20 mm shim. I've ordered a 2.10 to put in, but I have a quick question.

I know I'm going to run out of room to shim soon, as there isn't smaller shims. what are the options if I need to go below 2.10 in a few years?

Should I be on the lookout for a KZ750n1 head in good condition just to have as backup?

Opinions?

You can have the valve stem ground,maybe give you 0.3mm to play with....
New seats?

That is correct. Tip the valves to get back closer to the middle of the shim range.

Jay

So how and who can replace valve seats? Sounds kind of tricky. Do they screw into the head or is there a reverse taper to secure them? Thanks, Steve

There should also be a 2.00 shim. The bike could run for years before it wears into two shims sizes. You might also be able to remove the valve and grind some off the end. There is a spec for the valve length in a factory service manual and you can grind them until they reach the minimum which might give you the ability to get back up into the thicker shim range.

New seats can be pressed in; then a valve job is required and it would be a great idea to replace guides at this point. I suggest it would be far less expensive to find another serviceable head and pitch the one with worn seats.

shighley wrote:

So how and who can replace valve seats? Sounds kind of tricky. Do they screw into the head or is there a reverse taper to secure them? Thanks, Steve

a good machine shop can replace the seats and yes do the guides at the same time. it is a bit tricky to change the seats in alum heads, you do it worng and it gets ugly real quick,, got the been there done that shirt.
But in the end new guides and seats, and replace the valves, you will have a head that will last for a long time

Thanks guys. Yeah, I know I've got some time with this head before something major needs to be done, but just wondering if it would be prudent to be looking for a servicable head on the cheap.

all good options

A possible sourse for either new or used heads:

1. www.redlinecycle.com
2. www.dynoman.com
3. www.crconlinecatalog.com
4. vintagecyclepart.com
5. www.kzzone.com
6. www.sudco.com
7. www.zienterprises.com
8. www.z-power.co.uk
9. www.oldkawman.com
10. www.partsnmore.com

Just a few from my listing!

What is all the talk about new valve seats? The head only needs the valves tipped.

Jay