valve lapping

undiablo wrote: Did you use prussian blue to check a perfect valve seat?

A chisel tooth, black, permanent magic marker works excellent for checking seat condition

koloj wrote: It seems not matter how much I lap them I do a water test and little leaks I have course and fine compound and they all sound set noise wise is that normal or should they be like super super tight...input would be great also water stay in the head chamber not like It drains like super quick

Sometimes lapping just won't do the job you hope for. Obviously I can't see the leak from here.....but if it's just a tiny drop and if you're low on funds and can't afford a proper valve job.....then just run it.

If you post up some pictures of the valve faces and the seats and actually the leak I could advise you better. I have a bunch of old KZ900/1000 valves that I can reface and send to you if you're dead broke. You can try to lap them in and see how you make out....just holler back and I'll do what I can...

LarryC wrote:

oldzed wrote: Some will not agree with this but...

For years when we ground in 2 valve heads we always put a round headed chisel on the centre of the valve and gave it a LIGHT , and I repeat LIGHT, tap with a hammer. It helped seat the valve fully for testing..

Nowadays with modern multivalve heads with tiny exotic valves we don't do this.

You fooled yourself if you think that did anything helpful.

I bow to your greater experience with these engines
The guy who trained me 30 years ago did it so I did it too
The guys I trained saw me do it and did it too :lol:

Your a hell of a nice guy Larry.

You are an awesome guy LarryC

For sure thanks ya well I was given a parts bike with it and think gonna use that head...I lapped ones on that head and so far water test from the top worked I'll find out if their sealed I left springs in my buddies car but ya If that don't work ya I'm kinda stuck sorry just been doing lot of work on the bike I just soda blasted the whole engine past few days its looking nice old gaskets were caked on their was only way to get a nice smooth surface for the new gaskets and head gasket...but I'll let ya know on how it goes otherwise valves would be great cause ones I was working with took like hours to clean the carbon off...but fingers crossed I will post some pics before after did a lot of work I'm very persistent when come to something I'm gonna be riding on the road...with these crazy drivers now adays

Here some photos of valves and other pics as I've been working on it

Can anyone reccomend a dye or what can be use to mark thevsewts and valves cause I'm close getting them good do u check it after lap compound or without it

www.grainger.com/product/DYKEM-Blue-Layout-Fluid-2C945

leon

Larry mentioned a chisel tipped sharpie. I am no expert but it worked well for me also.
Wayne

531blackbanshee wrote: www.grainger.com/product/DYKEM-Blue-Layout-Fluid-2C945

leon[/qu


ote]

But in worse case if the valves are not perfect how much is it gonna hurt my performance

your compression numbers will answer that question for you.
make sure the valves are all shimmed and check the compression.
it takes at least 65lbs to make combustion.
engines are worn out and needing rebuilt if they only have 100lbs.
a good solid running engine will have 140+ lbs of compression.
thats the ultimate factor on how an engine will run.

compression.


leon