KZ750 CSR Valve guide oil seal failure update

Hey Guys, So for those of you who replied and helped out in my previous thread, thanks to you and I have some more info. For those who didn't see the last thread heres the basic runthrough.

Last fall the bike was running well although I knew the valve guide oil seals where on the way out because the bike would smoke upon deceleration and I knew the seals where old. When I was on a long ride, the bike lost one cylinder and sputtered oil from the exhuast of the same cylinder. OIl was also leaking from the exhuast where it seals into the head. I knew it was the oil seals and fixed the problem with a new set of VITRON oil seals. Problem solved. Or so I thought.

Recently the same thing happened on the same cylinder. Oil out the exhaust, after running perfectly for about 500 miles. It seemed like it was the valve guide oil seals at fault again, although there is some question as to whether those seals could allow that much oil through. Reguardless, if it where a fault of those seals, it was either due to my mistake on installing them or it was a worn out valve guide that caused the accelerated wear of the oil seal. It was undetermined until tonight when I took apart the head.

Heres the news. Upon removal of the intake valve of the oil soaked cylinder, it looked totally fine. Seal looked fine and was intact around the entire valve. Also, the valve seemed to fit perfectly within the guide, not having any noticeable play. So that rules out wear of the guide. So my question to you all, what could be causing all this oil into the cylinder??

My hints and useful info. Valve guide and seal looks OK, as far as I can tell. Both intake and exhaust have a TON of carbon burnt onto them. As expected with a oil loaded cylinder. Head gasket was BRAND NEW as well. I was thinking it could have been the oil supply to the head leaking into the cylinder but why would it take so long to show up? Basically im out of ideas and want to figure this out. I know it will run if i rebuild it but who knows for how long till this happens again.Any help is appreciated and sorry for this HUGE post.

Thanks!!

Could be piston rings. Could be a head gasket leaking as well as the O ring seals for the passages going up to the head. On my 750 twin, there are two oil pipes with two O rings each connecting the cylinder to the head.

I think you should also check for a cracked head.

I forgot to say that the compression is 165 lbs on both cylinders. Could the compression still be good but allow for so much oil into the cylinder?

What would be the best way to check for a cracked head? It seems totaly fine when I examine it. Are we talking micro cracks?

Thats what I was thinking with the oil passages too. How could I tell if they where an issue?

What would be the best way to check for a cracked head?

Back when I built engines using dinosaur bones, cracks were found doing a test called magnafluxing.

I forgot to say that the compression is 165 lbs on both cylinders. Could the compression still be good but allow for so much oil into the cylinder?

Interesting. Only way I can think of it would be if an oil ring was broken?

Thats what I was thinking with the oil passages too. How could I tell if they where an issue?

I would think there would be visible evidence.

Bountyhunter, you are the man.

I think I am going to avoid the crack test just because its pricey and I doubt that could be the issue. What I'm thinking is that its the oil feed to the head. It should be sealed up by the head gasket and I really don't see how it could leak into the combustion chamber but nothing else could cause that big of a leak in a cylinder with good valve guide seals and good compression.

On some engine diagrams, there is two orings that seal around the oil feed and I dont see any on my parts. The thing is though, that I cannot seem to find new ones to buy. Just trying to think on how I could seal those up for sure.... Ideas?

bpchura wrote: Bountyhunter, you are the man.

I think I am going to avoid the crack test just because its pricey and I doubt that could be the issue. What I'm thinking is that its the oil feed to the head. It should be sealed up by the head gasket and I really don't see how it could leak into the combustion chamber but nothing else could cause that big of a leak in a cylinder with good valve guide seals and good compression.

On some engine diagrams, there is two orings that seal around the oil feed and I dont see any on my parts. The thing is though, that I cannot seem to find new ones to buy. Just trying to think on how I could seal those up for sure.... Ideas?

those pipes have no O rings?
That would probably make a major leak. You can find O rings at many places like plumbing supply. With the head off, you should see the oil pipe tops and each should have a groove for the O ring. Use calipers and get an inside diameter in the groove. NOTE: the pipe has to be pulled out of the cylinder to get to the second O ring.

The part numbers show up as:

92055A in the drawing and P/N is 92055-094

No eBay APP ID and/or Cert ID defined in Kunena configurationsources:

www.nwvintagecycleparts.com/search-resul...q=92055-094&st=spart


www.partzilla.com/parts/detail/kawasaki/KP-92055-094.html

Weird. It seems like my oil passages dont have a groove cut out for the O ring. I attached an old picture I took during a rebuild awhile ago and while it is sort of difficult to see, there does not appear to be any groove for an oring. Does it just sit on the nipple?

On mine, the pipe has a groove on both ends. One O-ring seals into the cylinder and the other into the head. Maybe yours is different.

Bountyhunter, do you think you could give me the part number of the oil passage pin that is correct? I think a previous owner may have switched it out with one without grooves? Whatever happened, mine are smooth and i suspect it to be the cause of the leak.

No eBay APP ID and/or Cert ID defined in Kunena configurationThe number shown is 92042-039.



www.partzilla.com/parts/detail/kawasaki/KP-92042-039.html

www.nwvintagecycleparts.com/search-resul...q=92042-039&st=spart