KZ1K'S MOTOR

There seems to be some confusion as to which term is used for what part of the valve. The margin is important, if to thin the valve will have a tendency to burn, especially the exhaust valves. This is why there is a minimum thickness to be checked after resurfacing the valve "Face", which is the seating/ sealing surface. Also there is a minimum and maximum for this width, along with its mating surface on the seat.
Without the correct tools to do this part of the job, you really need a qualified machine shop. Like I said you may attempt to do the valve lapping at home, BUT you must still use the manual for the seat and valve dimensions, keeping in mind that the job will be a repair and not a rebuild.

PLUMMEN wrote:

get everything cleaned up first and measured,then you can decide what parts are needed.
a valve job isnt that big of a deal for a shop that does them all the time,so it shouldnt take that long to get them back.
spend a few bucks after you get the cylinder off and take it and the cleaned up pistons to a bike shop and have the bores and pistons measured before spending money on rings

I agree completely - take a deep breath, get everything inspected/measured. You still don't know for certain why you were losing compression. Better to understand what you have before diving in and spending money - trust me, it will be cheaper in the long run if you inspect/get it all inspected.

And for Pete's sake, give one of the valve job shops a call! They can walk/talk you through everything that's involved/critical with a valve job. And like I said, Larry is probably watching this thread anyways....Larry? Are you there?

whats larrys #?

www.flowbenchtech.com/porting/CRH/

ok talked to larry. he said at the minumum, new cam chain/master link, piston rings.

have the head resurfaced, check valve guides and do a valve job.

can someone explain to me checking the top idler, rear idler, front rubber sprockets, and rubber pillows? can i check them now, or does the motor need to be together?

they are rubber coated.you are looking for cracks in the rubber or chunks missing.wipe em off and eyeball em real good.

leon

My question is, where did all the rust come from? With that amount of rust, a valve job, cylinder hone and new rings is the absolute minimum you should be doing.

TerryK wrote:

My question is, where did all the rust come from? With that amount of rust, a valve job, cylinder hone and new rings is the absolute minimum you should be doing.

i dont know terry. if it was water cooled i would have a guess, but its not. and why was it only 1 cylinder? say it sat in the rain, all the cylinders would have surface rust.


i did a water test to check the valves


results on intake is 2-3 leak water.

on the exzaust its not leaking yet at all....ill give it a few more minutes.

so for sure on the intake 2-3 leak.

#2 has a leak through exzaust.

So basically you are in it to rebuild the head. If you have already talked to Larry C, then he'll have given you good advice. I'm glad you're getting this figured out. It won't be long until you know more about this bike than your craigslist "expert" :laugh: :laugh: :laugh:

kz1k wrote:

TerryK wrote:

My question is, where did all the rust come from? With that amount of rust, a valve job, cylinder hone and new rings is the absolute minimum you should be doing.

i dont know terry. if it was water cooled i would have a guess, but its not. and why was it only 1 cylinder? say it sat in the rain, all the cylinders would have surface rust.


i did a water test to check the valves


results on intake is 2-3 leak water.

on the exzaust its not leaking yet at all....ill give it a few more minutes.

so for sure on the intake 2-3 leak.

Use a solvent like Varsol. Water has too strong a surface tension and won't show leaks well.

Once you know which ones are leaking, disassemble the head and check each valve for obvious signs of being bent. If none are bent, lap the valves. It may be that's all it needs as far as the head goes. Lap ALL the valves, reassemble the whole thing and do the solvent test again.

One thing: do you see any signs of valve to piston contact? Inspect the pistons closely for tiny crescent shaped dimples.