Exmark Lazer Z Kohler CH740 problems

[VegetiveSteam]

If you're not hearing the lifters clattering your oil pressure is probably okay. On the Command twins, lifter tick is usually the first sign of low oil pressure. You also won't see much oil running with the rocker covers off. There is no pressurized oil in the upper end. Are you torquing the rocker arms to 160 in lbs?

If you turn the engine over by hand do all of the rocker arms seem to move the same amount once you re-torque them? I doubt this would be your issue but check if they all move the same so you can rule out a flat cam lobe.

 

[NxtGoRnd]

If you're not hearing the lifters clattering your oil pressure is probably okay. On the Command twins, lifter tick is usually the first sign of low oil pressure. You also won't see much oil running with the rocker covers off. There is no pressurized oil in the upper end. Are you torquing the rocker arms to 160 in lbs?

If you turn the engine over by hand do all of the rocker arms seem to move the same amount once you re-torque them? I doubt this would be your issue but check if they all move the same so you can rule out a flat cam lobe.

The other intakes are moving the same the other exhaust seems fine I pulled the lifter and the cam does not look very worn. Saying that I know it is not proper measurement the plug on #1 side looks normal and the #2 side is black. I think the cam is okay. I did torque to 160 inch pounds.

 

[NxtGoRnd]

Installed new lifter still getting same results swapped the rocker pushrod and lifter from a different valve same results. I believe I have a worn cam lobe on #2 exhaust man wish I had started there LOL. As said first post cognitive abilities have definitely gone down hill, thinking I will put in a cam but apparently there are no oil pumps available. Seems discontinued and no replacement hate to install cam and not oil pump. Pump #2401226S have not been successful at finding aftermarket either.

 

[VegetiveSteam]

Installed new lifter still getting same results swapped the rocker pushrod and lifter from a different valve same results. I believe I have a worn cam lobe on #2 exhaust man wish I had started there LOL. As said first post cognitive abilities have definitely gone down hill, thinking I will put in a cam but apparently there are no oil pumps available. Seems discontinued and no replacement hate to install cam and not oil pump. Pump #2401226S have not been successful at finding aftermarket either.

The 24 012 26-S should be the camshaft. The oil pump # should be 24 393 53-S and like you mentioned it is discontinued. The only way to get an oil pump from Kohler now it to buy the complete closure plate assembly. Might check ebay for the pump. If I hadn't thrown them away I would have given you an oil pump. I had two from one of my schools brand new in the box sitting around for a few years. After I retired I got tired of looking at them and cleaning up some junk in the basement last year they found their way to the trash. I guess I should have put them on ebay. Being NLA they would have probably gone fast.

 

[VegetiveSteam]

If you do find out it is a flat cam lobe and you are the original purchaser and you have a receipt showing the purchase date, I'd contact Kohler tech service and explain everything just like you did here. You can call them at 920-459-1579 or you can go to kohlerengines.com and leave them a message there. They will get back to you.

I'm guessing the unit has the same amount of hours on it as it did when you stopped using it in 2015? Your engine was built in June of 2014 and you stopped using it in 2015 so you can't have but maybe 50 hours on it if that many unless you were using it commercially. There is nothing a user can do to cause one flat cam lobe. If you can do the work yourself, see if Kohler will do a Policy Adjustment for parts only. The worst they can do is say no but I feel it's worth a shot.