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Discussion Starter · #1 ·
Hi, i'm having issues with the valves on my ztrak 920a. After replacing one of the cylinder heads because one of the valve guides had moved and one of the push rods was bent. I fitted new push rods and set the gap between valves and rocker guides at .05mm to .10mm. The machine ran well for about an hour and a half and then i heard a ping and the engine lost power. It was only firing on one cylinder. After taking off the rocker cover i noticed one push rod had come out of place. I noticed that the gap between valve and rocker was very big and measured at .15mm. All the bolts on the rockers were tight. I did notice that the rocker arms seem to have wear (refer attached photos). I assume that the rocker where the push rod came out could have had the same gap. I set everything up previously to the JD technical manual. Any ideas why i could habe got such big gaps after only an hour and half of running. PS i am going to check the gaps on the good cylinder to see if they are ok or are excessive the same as the bad side.
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Is this a Kawasaki? I assume it is.
 

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I'm still scratching my head about your original issue. I think therein lies the reason for the issue you are having now. I really don't understand the valve guide "moving" part but I suspect that reassembly has something to do with what's going on now.
 
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Discussion Starter · #5 ·
I'm still scratching my head about your original issue. I think therein lies the reason for the issue you are having now. I really don't understand the valve guide "moving" part but I suspect that reassembly has something to do with what's going on now.
The original issue was that one of the valve guides moved in the head causing one of the push rods to bend. I have seen that the valve guide moving is quite common on the kawasaki fx730v.
 

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Discussion Starter · #8 ·
What does the bottom of the lifter and cam lobe look like?
I am not sure. I could only see by torch and feel by locating the push rod. The valve where the push rod popped out is the problem one however the valve that was still in had the large gap of around 1.5mm (.059") after it was set at around .08mm (.0031"). I was setting the valve gap to .05mm (.002") to .10mm (.004") which was in the technical manual i have. The was a post somewhere that kawasaki and jd had conflicting gap settings (.004" to .006" in one and .002" to .004" in the other).
 

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I am not sure. I could only see by torch and feel by locating the push rod. The valve where the push rod popped out is the problem one however the valve that was still in had the large gap of around 1.5mm (.059") after it was set at around .08mm (.0031"). I was setting the valve gap to .05mm (.002") to .10mm (.004") which was in the technical manual i have. The was a post somewhere that kawasaki and jd had conflicting gap settings (.004" to .006" in one and .002" to .004" in the other).
That might have been my post when I was working on my Z950R. I don't recall the spec but yeah they were different (Kawasaki vs JD manuals) and I went in the middle.


I have a slightly larger engine but the specs are the same. If I remember the process and I think it is the same on the horizontal Kawasaki in my X585 but you adjust the clearance by loosening a nut and turning a concentric bolt then tightening up the nut to lock it in place. I am used to doing valve clearance checks on motorcycles where we had shim swaps. I recall that when I first did this on my X585 I was having a heck of a time. I would adjust the concentric to get the proper gap but it would turn ever so slightly as I was tightening the lock nut. This was because the slop in the wrench I was using to hold the concentric bolt. I seem to remember having to go overly tight on the gap and then when tightening the lock nut it would loosen up to where it should be. That is from memory. I would, if it were me, set it again making sure to check the gap before and after tightening the lock nut. Running it a few hours and checking again. Maybe the bolt slipped.

I am going off memory on this because I didn't read the entire post above but I provided a link for you when I was going through the valve clearance check on my ZTrak.
 

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When i worked for a small engine company we had a generator with a kohler that had a bent push rod. Took months to get in, then when we finally had it installed it bent upon first crank again.

my question first would be, why did it bend in the first place. check that out before trying to fix.

i left shortly after it bent the second time so i never did get the final outcome.
 

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When i worked for a small engine company we had a generator with a kohler that had a bent push rod. Took months to get in, then when we finally had it installed it bent upon first crank again.

my question first would be, why did it bend in the first place. check that out before trying to fix.

i left shortly after it bent the second time so i never did get the final outcome.
Yeah push rods don’t just bend by themselves
 

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I would make sure that you ain’t got a cam going flat. I have seen both roller cam and flat tappet cams go flat, and with the epa mandating a lot of the anti wear agents out of oil, it just makes it worse.
 
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