85 zx600 ninja

[chuck hahn]

I found a few discussions on the soft valves issue by doing google searches. From what ive uncovered the estimated bad engines were somewhere around the first 1000 to 1500. Least ive got something to look at next time i go over to my buddies place. IM about 80/20 on pulling the trigger.

[Maddevill]

I've had to do several Ninja 600 top ends. And,if this bike has had a" Top end" done, you better hope they didn't just grind the valves. That would remove most of the rest of the hard plate and make things way worse. Only real fix is a new set of valves. On one 86 Ninja 1000 I worked on ,one intake valve had pulled completely through the seat.

Mad

[Maddevill]

I found a few discussions on the soft valves issue by doing google searches. From what ive uncovered the estimated bad engines were somewhere around the first 1000 to 1500. Least ive got something to look at next time i go over to my buddies place. IM about 80/20 on pulling the trigger.

I'm not sure about that. I saw a whole lot of them. Both from 85 and 86. If that number came from Kawasaki I'd be very suspicious. Remember, they were desperately trying to cover their asses. Apparently their main supplier of valves screwed up. Took awhile to discover the extent of the problem. By that time there were a lot of bikes out there.
I'm not saying to not buy the bike. If I ever come across a good one ill snap it up. But I'd plan on doing the head 100%

Mad

[Maddevill]

On a related note, my friend had a 1986 Ninja 250. It had the bad valves. It got progressively harder to start as the valves sank into the seats. So he had his son tow him and tried to bump start it. Backfired through the intake and set his airbox on fire. He was lucky to get it out. That was another one I had to fix.

Mad

[chuck hahn]

Mad.. I've been thinking do the valves regardless. I'm trying to see what the superceded part numbers were for the replacements. That or any info on what all years are the same as the 85. To be certain is better than to believe it's been done. I'll also look at the engine number.

Anyone know where I might find old service bulletins from back in the day?. I sure am leaning hard but would feel more comfy knowing I can buy the upgraded valves.

[chuck hahn]

I enquired about any valve work and it did have some valves replaced, lapped, and while t was apart it was honed and new rings installed. It ran and rode as it should until the starter clutch went South. Im gonna pull the trigger and clean the carbs and redo the clutch and see what happens.

The only thing ill need for the starter clutch job is the triangular rubber dampers which isnt that big a deal. Kawasaki says they are still available so ill start there first. If they cant come through ill cruise Ebay until i have all 8 in hand.

[Maddevill]

Oofah. If they REPLACED the valves then you're good. If they lapped them, either you or the next owner is going to have a Sad.

Mad

[Maddevill]

On a somewhat related note, I was working on a friend's 87 Ninja 750. Did you know those things have a BELT driven alternator and that it's INSIDE the cases ? I didn't either until I found his broken. I figured out a way to change it working behind the cylinder head but it was touch and go.

Mad

[chuck hahn]

Mad. Supposedly it was a combo of "some" valves replaced and all lapped. I'm currently trying to find the superceded part numbers for the valves. That or has Kawasaki just replaced bad valves with known good ones and kept the same part number? Do you think it's possible that if this bike showed some obvious bad ones and some not being bad when it was opened up that the issue has been taken care of?

Thing is was it just intake valves then? Just exhaust? Or a mix and match of both....know what I'm getting at?. Either way it was in fact running after the work had been done.

And another question for the ninja officials....what all years used the same part numbers as the 85 600?. My thoughts are that if the 85 year was the only year with the problem but they used the same head/valves setup for multiple years then it stands to reason I could buy 86 parts fiche valves and put in the 85 head. Make a reasonably theory?

[GS1150Pilot]

I think 85 and 86 share everything.

[Maddevill]

Mad.. I've been thinking do the valves regardless. I'm trying to see what the superceded part numbers were for the replacements. That or any info on what all years are the same as the 85. To be certain is better than to believe it's been done. I'll also look at the engine number.




Anyone know where I might find old service bulletins from back in the day?. I sure am leaning hard but would feel more comfy knowing I can buy the upgraded valves.

I don't think you can get any of the bad valves anymore. They've been purged. Anything you can get now will be ok.

Mad

[Maddevill]

I'm not sure but the bad valve we saw were always Intake. And like I said above, you can't get bad valves anymore. They made sure they were removed from the system. If it was me, and I couldn't confirm that all the Intakes, at least, were changed, I'd just replace all the Intake valves. That's what we did on my friends 86 ZX1000. I was so confident in that bike after I had repaired it, that the day after the work was done, we took it on a long trip. I ended up buying it from him. Never had any more valve problems.

Mad

[salty_monk]

I'd for sure be looking to make money on the deal....

[chuck hahn]

Might not be too much left on the bone. Im assuming intakes and fork seals will need replaced. Tires are for sure junk. But i think its worth the save. But on the right day and right buyer who knows.

[Buffalo Bill]

I would hold my worries about the valves until after I adjusted the valve clearance and did a compression test.