Valve adjuster screws & lock nuts

[Teh_K]

Is it common to have these two pieces fail? Four out of the 16 valves had the same problem:

The locknut locks up on the screw (like it's crossthreaded). I can take the screw and nut (still connected) out of the engine and the nut still won't budge.

The 1st valve that it happened on I just replaced the nut and screw and everything was good, but then 3 more went this way so now I'm gonna have to get 3 more...

Just seeing if this a common issue.

[woobie]

Never had that problem on mine (03 600).

[The CyberPoet]

I've never seen it happen on a Kat before. This means one of two things is probably happening (or has happened):

(A) Drunk incompetent person did the mechanical work on a previous valve adjustment and did cross-thread them;
AND/OR
(B) the oil jets that spray the cams & upper engine are blocked or defective, or the oil pump's pressure regulator is defunct (or the pump itself isn't right any more), so it effectively heat-welded itself into place.

Since you have to take them out anyway, I'd suggest splitting one of the nuts off and looking at the threads very closely to see if it was a case of mechanical ineptitude; if not, I'd start looking at the oiling system very very closely.

Good Luck with it!
=-= The CyberPoet

[Teh_K]

Well, I don't think they've been heat welded together... Here's a little more of the storey:

4 of the valve screws locked up, but I was able to save 2 of them. On the two that I saved, at the moment I felt something was wrong, I took them out, managed to get the nut off, and I could see little tiny metal shavings (not a lot, only a couple) in between the thread on the screw. I cleaned both parts and examined the thread (it appeared fine), and tried it again. And it worked... for 2 of the 4.

With the OTHER two, however:

The nut on 1 pair rotates a little one way then gets stuck, then can rotate the other way, and then gets stuck again.

The other one is flaky (figuratively, not literally). It feels as if it has 'rough spots' as you rotate the nut along the screw. And there just happends to be a rough spot where I want it to be set at (so I can't tighten it).

But, a tiny metal shaving or two were found on all 4 pairs.

(PS - Does it mean anything if the metal cover that covers the top-center of the cam chain is discolored? I has some streaks that kind of look like burnt oil...)

[The CyberPoet]

(PS - Does it mean anything if the metal cover that covers the top-center of the cam chain is discolored? I has some streaks that kind of look like burnt oil...)

It means it got too hot at some point (and was probably turned off right afterwards), and the oil you are using now doesn't have enough detergents to have washed the oil residues away yet.

Cheers
=-= The CyberPoet

[Teh_K]

Hooray! A dealer south of Raleigh actually had valve screws and locknuts in stock! 4 of each, actually

So, I bought all 4 he had along with a signal cover gasket and the little washer that goes on the top screw (I was missing it...) and finally closed up my engine tonight. He seemed to know what he was talking about, and said that my problem was most likely caused by whoever before me over torque-ing them. Anyway, he also mentioned that all Zuki bikes use the same adjuster screws and locknuts... I thought it was interesting, so FYI...

Next is the carb sync (already got the Morgan CarbTune II), and then I can finally ride again

It means it got too hot at some point (and was probably turned off right afterwards), and the oil you are using now doesn't have enough detergents to have washed the oil residues away yet.

Yea, I think the bike has had only Suzuki factory oil in it up to this point. After all this maintenance I'm switching to Castrol GPS.

One question, tho... is there supposed to be motor oil in the cavity behind the signal generator cover? There wasn't a lot, just a couple drops when I took the cover off...

[The CyberPoet]

Anyway, he also mentioned that all Zuki bikes use the same adjuster screws and locknuts... I thought it was interesting, so FYI...

What he meant was all of them that use valve nut adjusters. Not all Suzuki's use them, and not even all Kats use them...

One question, tho... is there supposed to be motor oil in the cavity behind the signal generator cover? There wasn't a lot, just a couple drops when I took the cover off...

It's not drowning in oil... normally, a few drops escape past the oil pressure switch below the signal generator and that's all the oil that will build-up in there. That's just the way it should be

Cheers
=-= The CyberPoet