KZ900LTD - Love To Dawdle Project

I posted up in introductions after joining 23 years ago, finally dragging my '76 KZ900LTD basket case out of the backyard to work where I sometimes stay late to putter on my project (which isn't very often). I sold my running bike to a college kid friend who got in over his head and bent a valve attempting to repair broken valve spring retainers, then returned the bike to me as a basket case. Bill is a colleague of mine and encouraged me to post up my project here, I suspect to motivate me more than anything, but I also request your guidance and advice as this is beyond my general knowledge of the motorcycle maintenance that I do for a living.  I sorted through the valves to see what I had, looks like I have to buy all the valve spring retainers, and an intake valve for cylinder 4.The valves for cylinders 1, 2, and 3 looked good so I water tested them for a baseline to see if they needed lapping. I’ve read you can use acetone to test, but I understand that method has mixed reviews. After 90 minutes cylinder 1 still holding water, while cylinder 2 and 3 leaked respectively. I'll lap them and test again once I order and receive the new intake valve.

   

Am I on the right track?

Yes you are, personally I fill the "port" rather than the combustion chamber and use white spirit

Thanks Wookie! I'll give them a quick lapping and proceed with reassembly.

+1 on Wookie's method.  I've found you can fill enough of the chambers to cover the valve seat area with the head flat on the bench. Carb cleaner also works, gently spray into chambers until full enough.  I put a blue paper shop towel on the bench under the head and you can see where the leak is.  I do the exhaust separate from the intake to tell which valve leaks.

Typical ethylene glycol antifreeze can find leaks that water may not, due to lower surface tension.  Nonvolatile, cheap, reasonably non-toxic, won't promote rust or corrosion.

Good Ridin'
slmjim & Z1BEBE

slmjim+Z1BEBE wrote:

Typical ethylene glycol antifreeze can find leaks that water may not, due to lower surface tension.  Nonvolatile, cheap, reasonably non-toxic, won't promote rust or corrosion.

Good Ridin'
slmjim & Z1BEBE
 

Brilliant idea! It's slippery and it tastes great too!

I went down the interweb rabbit hole yesterday looking for new valve spring retainers and got lost in the whole KPMI and APE titanium under bucket shim conversion. So I took another inventory of what I have, evidently the kid did buy new valve spring retainers. Now my concern is if the springs wore through the last retainers, how long are these new, thinner retainers going to last? I'll run these 'for now' as my intention is to just get the bike back together and running, learning as I go.