Valve rocker lock nut trouble FX751V

[JWF]

24.5 V Twin Kawasaki in Z925A John Deere commercial duty Zero turn.

Long story short; I adjusting valve lash and wound up with a stripped locknut for the adjusting bolt. As I broke loose the first nut to adjust the first valve, I wondered how the last mechanic in this engine got the lock nut so tight without stripping it?

Went on and successfully adjusted 3 of the 4 valve rockers. The last of the 4 gave me a lot of trouble. Had to tighten and recheck clearance 1/2 dozen tries and the lock nut finally gave up.

I have worked as a mechanic, automobiles, in the past, but will admit that it's been a while and I am at east, rusty.

In thinking this over, after the fact, I am wondering if these nuts might be tighten to failure hardware? Also got to wondering if the failed nut might have been damaged before I put a wrench on it? Thinking that, if it had been over stressed, in the past, maybe that explained it giving me so much trouble getting the adjustment right?

Of coarse; I stepped in this pile after working hours so I haven't been able to call a dealer to check any of these questions or check on parts availability.

I realize that I may be looking for excuses for damaging my parts. I am not usually a "get a bigger hammer" mechanic, but this may be all my fault.

Thanks for your thoughts, John

 

[StarTech]

Can't comment on the history of the rocker adjustment problem. Anything possible. Just now you got to replaced the parts.

Bare minimum is the 92153-7100 specialized bolt and the 312AA-0600 6mm nut. Then you got to inspect the bracket 11055-7009 and the collar 92152-1689.

And sure the tiny stud that prevent the bracket from rotating is not broken off. If it is then it a complete head replacement.

 

[txmowman]

The “tiny stud” is there for assembly purposes only. That and the cut out in the bracket show the line worker how the brackets fits. That’s all. It is the bolt torque that holds the bracket, not the casting.

 

[StarTech]

Then someone at Kawasaki is not torquing the screw very well even with the Loctite applied. As nearly every engine that has a bent push rod here has these studs broken off. Should not happen if the screw torque alone was preventing bracket from twisting out of place.

 

[JWF]

Then someone at Kawasaki is not torquing the screw very well even with the Loctite applied. As nearly every engine that has a bent push rod here has these studs broken off. Should not happen if the screw torque alone was preventing bracket from twisting out of place.

Can't comment on the history of the rocker adjustment problem. Anything possible. Just now you got to replaced the parts.

Bare minimum is the 92153-7100 specialized bolt and the 312AA-0600 6mm nut. Then you got to inspect the bracket 11055-7009 and the collar 92152-1689.

And sure the tiny stud that prevent the bracket from rotating is not broken off. If it is then it a complete head replacement.
View attachment 69544

Hi Star Tech,

Thanks a lot for the schematic, and your thoughts. I did a search hoping to find a schematic with no luck.

Are you saying that the factory uses locktite on the adjustment bolt and nut? That would explain what I assumed was a very tight nut, when I first broke these loose.

Calling for parts Moday morning. Will I be better off dealing with a Kawasaki dealer, or local John Deere dealer? The JD dealer has yet to let me down.

 

[JWF]

Then someone at Kawasaki is not torquing the screw very well even with the Loctite applied. As nearly every engine that has a bent push rod here has these studs broken off. Should not happen if the screw torque alone was preventing bracket from twisting out of place.

Can't comment on the history of the rocker adjustment problem. Anything possible. Just now you got to replaced the parts.

Bare minimum is the 92153-7100 specialized bolt and the 312AA-0600 6mm nut. Then you got to inspect the bracket 11055-7009 and the collar 92152-1689.

And sure the tiny stud that prevent the bracket from rotating is not broken off. If it is then it a complete head replacement.
View attachment 69544

Hi Star Tech,

Thanks a lot for the schematic, and your thoughts. I did a search hoping to find a schematic with no luck.

Are you saying that the factory uses locktite on the adjustment bolt and nut? That would explain what I assumed was a very tight nut, when I first broke these loose.

Calling for parts Moday morning. Will I be better off dealing with a Kawasaki dealer, or local John Deere dealer? The JD dealer has yet to let me down.

 

[JWF]

Then someone at Kawasaki is not torquing the screw very well even with the Loctite applied. As nearly every engine that has a bent push rod here has these studs broken off. Should not happen if the screw torque alone was preventing bracket from twisting out of place.

Can't comment on the history of the rocker adjustment problem. Anything possible. Just now you got to replaced the parts.

Bare minimum is the 92153-7100 specialized bolt and the 312AA-0600 6mm nut. Then you got to inspect the bracket 11055-7009 and the collar 92152-1689.

And sure the tiny stud that prevent the bracket from rotating is not broken off. If it is then it a complete head replacement.
View attachment 69544

Hi Star Tech,

Thanks a lot for the schematic, and your thoughts. I did a search hoping to find a schematic with no luck.

Are you saying that the factory uses locktite on the adjustment bolt and nut? That would explain what I assumed was a very tight nut, when I first broke these loose.

Calling for parts Moday morning. Will I be better off dealing with a Kawasaki dealer, or local John Deere dealer? The JD dealer has yet to let me down.

 

[JWF]

HMMM! I am obviously having some trouble with the site.

Sorry for the duplicate responses

 

[txmowman]

Then someone at Kawasaki is not torquing the screw very well even with the Loctite applied. As nearly every engine that has a bent push rod here has these studs broken off. Should not happen if the screw torque alone was preventing bracket from twisting out of place.

You are correct. The 726cc engines originally showed 11ft-lb of torque on the bracket bolt. All other engines using this design was 15ft-lb. The spec is now 15ft-lb. Align the bracket, torque the bolt, add a drop of green Loctite. Good to go.

 

[StarTech]

No the Loctite was used on item 130.

And in the US the JD Kawasaki mounted engines are on the US Kawasaki site. But they can be looked if you know where to look. So if you need a particular item post what it is and the engine's spec and someone here can look it up.

It is JD way of trying to force repair shops to buy only from JD s they also use their own part number to confuse things even more.