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Kohler Command 25 rocker arms off valve springs
- Thread starter elidukes
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If you have not already found it. Here is a site to look up part numbers and possibly the service manual for your engine is there as well.
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banjodunn
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G'day if the pushrods are straight then are the valve heights the same? If so then you should be able to push the valves down a little and they should spring back up if they do this then I would be refitting the rockers and setting valves on both cylinders and see what happens
Jon
Jon
Kohler has a problem with the 10 mm bolt holding the rocker arm down and tight stretching the threads in the head, loosening the bolt allowing the rocker arm to shift sideways. Sometimes the push rod will get bent or fall into the engine.
The rocker arms are positive stops, meaning no valve adjustments necessary. The 10 mm rocker arm bolt is torqued down to 100 inch pounds or 8-10 ft labs, if memory serves with the push rod out from under the rocker arm. Using a tool fabricated from a connecting rod, one then rocks the rocker arm back, depressing the valve spring and opening the valve and then sliding the push rod into place. You can also do the same thing by fashioning a wire loop and use a screw driver and either lift up or press down to compress the valve spring and open the valve so the push rod can be placed in the proper location.
You would use a pair of wire dykes to cut the wire loop, make another wire loop for use on the other valve.
The rocker arms are positive stops, meaning no valve adjustments necessary. The 10 mm rocker arm bolt is torqued down to 100 inch pounds or 8-10 ft labs, if memory serves with the push rod out from under the rocker arm. Using a tool fabricated from a connecting rod, one then rocks the rocker arm back, depressing the valve spring and opening the valve and then sliding the push rod into place. You can also do the same thing by fashioning a wire loop and use a screw driver and either lift up or press down to compress the valve spring and open the valve so the push rod can be placed in the proper location.
You would use a pair of wire dykes to cut the wire loop, make another wire loop for use on the other valve.
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MossRoad
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Bumping this old thread after I had the same thing happen last fall. I was picking up leaves for the last time, and as I was returning to the garage, the thing started running real rough and backfiring. I shut it off and couldn't figure out what happened. It would start but be real loud, so I shut it off and rolled it into the garage. Started looking around. Couldn't find anything. So I took the valve cover off and found on rocker cocked sideways and the push rod looking at me. Thought for sure I'd damaged something. Looked around on the internet, and found a few references. I ended up skipping using the wire to lift the rocker and just put it on an torqued it to 100 inch pounds. Since it has hydraulic lifters, there is no valve adjustment, so in my mind, I can't see a reason to go through the step of torquing it down then using a wire to lift it to slip the push rod under. Anyhow, it worked and all was well....
Until Friday. I was using the machine to bucket wet cement from a truck to behind our garage for a garage addition slab, and the thing made a pop and a puff of blue smoke came out the exhaust, and it sounded different, but not too different, and I was worried it was gonna do the same thing with the cement truck there, but I kept going. We got the pour done, and later in the day I fired it up to put implements away and move my car hauler trailer, and it started the same behavior from last fall. I ran it into the garage and let it cooled down. Pulled the valve cover, and nothing. It was fine. Hmmmm.... so I pulled the opposite valve cover and there it was, off on that side. So I torqued all of them down to 100 inch pounds on all 4 rockers and it fired right up.
If it happens again, I'm considering putting some locktight on them. Any thoughts on that? Thanks.
Until Friday. I was using the machine to bucket wet cement from a truck to behind our garage for a garage addition slab, and the thing made a pop and a puff of blue smoke came out the exhaust, and it sounded different, but not too different, and I was worried it was gonna do the same thing with the cement truck there, but I kept going. We got the pour done, and later in the day I fired it up to put implements away and move my car hauler trailer, and it started the same behavior from last fall. I ran it into the garage and let it cooled down. Pulled the valve cover, and nothing. It was fine. Hmmmm.... so I pulled the opposite valve cover and there it was, off on that side. So I torqued all of them down to 100 inch pounds on all 4 rockers and it fired right up.
If it happens again, I'm considering putting some locktight on them. Any thoughts on that? Thanks.
Loctite would seem to be a good idea. Prep accordingly. You didn't say how loose they were. Commands in general don't have this as a widespread issue. Enough on Briggs. Those studs get locked in w/ red. Briggs also have valve guides that migrate and can interfere with the valve action. It's worth a look whilst it is apart. Seeing though it is an exhaust valve and all.
MossRoad
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Thanks. I looked in there and nothing seems out of place except for the rocker studs were loose enough so that they could wobble left or right allowing the pushrod to escape. Really surprised nothing else was damaged.
SB-318 COMMAND TWINS 620-752
Rocker Arm Pivot Screw Torque Change
Reports of loose rocker arm pivot screws on Command twin engines has resulted in an increase of the
torque spec to 18.6 N·m (165 in. lb.). If you experience a loose pivot screw please retorque the rocker
pivot screws on both cylinders to 18.6 N·m (165 in. lb.) following the procedure below.
It is further recommended you perform this retorque procedure for any engine within the Serial
Number range of 43193XXXXX-43210XXXXX, when the valve cover is removed for service or repair.
1. Remove the (8) eight valve cover screws.
2. Remove both valve covers. Ensure the O-rings remain properly in place.
3. Bring the engine to top dead center piston position on cylinder #1 with both valves closed.
4. Ensure the rocker arms and push rods are in position and aligned properly on the valve stems.
5. Using a calibrated inch pound torque wrench, retorque the rocker arm pivot screws to
18.6 N·m (165 in. lb.).
6. Repeat procedure on cylinder #2.
7. Verify the O-rings are properly in place, then reinstall the valve covers.
8. Reinstall the valve cover screws and any previously used clips or brackets.
9. Torque the valve cover screws to 6.2 N·m (55 in. lb.).
Rocker Arm Pivot Screw Torque Change
Reports of loose rocker arm pivot screws on Command twin engines has resulted in an increase of the
torque spec to 18.6 N·m (165 in. lb.). If you experience a loose pivot screw please retorque the rocker
pivot screws on both cylinders to 18.6 N·m (165 in. lb.) following the procedure below.
It is further recommended you perform this retorque procedure for any engine within the Serial
Number range of 43193XXXXX-43210XXXXX, when the valve cover is removed for service or repair.
1. Remove the (8) eight valve cover screws.
2. Remove both valve covers. Ensure the O-rings remain properly in place.
3. Bring the engine to top dead center piston position on cylinder #1 with both valves closed.
4. Ensure the rocker arms and push rods are in position and aligned properly on the valve stems.
5. Using a calibrated inch pound torque wrench, retorque the rocker arm pivot screws to
18.6 N·m (165 in. lb.).
6. Repeat procedure on cylinder #2.
7. Verify the O-rings are properly in place, then reinstall the valve covers.
8. Reinstall the valve cover screws and any previously used clips or brackets.
9. Torque the valve cover screws to 6.2 N·m (55 in. lb.).
MossRoad
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Thanks!