"Especially seeing how sometimes a broken compression release mechanism will function then it will not, its a moving part not a cam lobe" "One that will fly out and not return until its good and ready. Hence the sometimes it spins fine and then other times it stops on the compression stroke" "after you eliminate all external probable causes then it will have to be an internal problem." First, we don't know positively that he has eliminated all external probable causes. I think, if you will check, that I told him in my first post that he may not have adjusted the valves correctly. There are other possibilities besides not following proper procedure in adjusting the valves. Also, there is nothing in any of his posts about the problem being intermittent. I sent him proper valve adjusting procedure plus compression release test to use AFTER adjusting the valves and you can also tell if it is a bad cam lobe OR the compression release mechanism its' self. Yes, a worn out cam lobe can cause much the same symptoms regardless of the presence of a mechanical compression release. I like to have some idea what I am dealing with before I just plunge in and start tearing apart. Do the cheap, easy things first. By the way, there is no "bump" in the compression release of this engine. Walt Conner

4 stroke cycle engine. At the points in the cycle where the compression tests are being taken, whether turning clockwise or counterclockwise......both valves are closed at the time the piston reaches the TDC mark. The difference (in the compression pressure) is that when turning backward, the compression continues to build up without any partial release of pressure just prior to the piston's arrival at TDC. TDC is the same point in the piston travel, whether you reach it by turning the crankshaft CW or CCW. The camshaft base circle is the portion of the cam where the brief "high point" (that opens the valve) is situated. During the portion of the 4 stroke cycle where air is being drawn into the combustion chamber (intake stroke), the intake valve is open because that tappet is riding on the cam lobe (large eccentric area). At the end of the intake stroke, the tappet descends toward the base circle (round area) of the cam, and the intake valve closes and the piston begins to ascend into the beginning of the compression stroke. Compression pressure commences to rise. The tappet is running on the base circle at this point, but the decompression high spot on the cam is approaching the tappet. At the moment this high point begins to open the intake valve, the compression has already reached a significant pressure value, but not quite high enough to stall the piston. At just about the point where the pressure would/could stall the piston, the high spot on the cam base circle runs into the tappet and opens the intake valve slightly. This allows some of the pressure to be released back into the intake runner, permitting the starter to maintain its momentum and successfully push the piston past TDC and into the power stroke part of the 4 stroke cycle. This method of decompressing is very practical (and simple) as it relies on on a principle of fluid dynamics whis is that a finite volume of fluid (air in this case) will move through a specific size opening at a specific pressure during a specific TIME interval. What that means is that at low RPM (cranking speed), enough volume of compression will be flowed through the open intake valve to actually lower the compression.....because at that low RPM the valve is held open to decompress for a LONG TIME (relatively speaking). But when RPM increases, the TIME the intake valve is held open decreases steadily and when full operating RPM is reached, the time the intake valve is open to decompress is nothing but a millisecond, and that is not enough to permit any significant decompressing. Wrapping one's mind around the 4 stroke cycle can be hard to do if you don't have a vocation involving stuff like this. I think I have put myself to sleep. Anybody else still awake? :^)

If you have compressed air available, you can perform a "Cylinder Leakdown Test" (described in Kohler ser manual, click link below). Follow the instructions in the manual carefully. Don't worry too much about not having a "per cent of leakage" guage, you can use your ears to judge (roughly) how much leakage is taking place. Basically, all you need is an adapter fitting to use the spark plug hole for putting compressed air to the cylinder, and a way to hold the crankshaft from turning. Each cylinder must be tested individually and the engine position set for each cylinder respectively. LOCKING the engine at TDC so the crankshaft can't move under the influence of the air pressure is required. DO NOT attempt a leakdown test if you can't hold the crankshaft from turning. *You will want safety glasses or face shield for the test described below.* You can remove the valve covers (one at a time) and run the engine at idle speed while you watch for puffs of compression leaking into the pushrod gallery. Look at the picture below and find the red arrows I have added. For your test, do not remove the rocker arms, this was simply the best image I could find to illustrate where to look. The arrows show where compression would leak into the pushrod gallery (and pressurize the crankcase). If you don't see any puffs of compression escaping from the head into the gallery at idle, give the throttle a quick jog while you watch. If you see leakage, the head gasket is defective. If you opt to do a leakdown test instead of (or in addition to) running the engine as above, you can remove the valve covers and look for escaping air in the same spots shown in pics. Here is a link that might be useful: ComProHoriz

Since you state you have the same issue, everything is identical except for the serial number of your Craftsman tractor. Here are my comments on your issues: Forget about watching the fuel filter and thinking that it is somehow starving for fuel (the filter itself), it is not. No matter what you think you see, it is not indicative of a problem. The "empty filter" subject has been debated ad nauseum and no matter what you say or do, the filter is not going to abide by the notion that it should be full of fuel. Going for a larger diameter fuel hose will not help you out either. The hose nipple at the tank, the filter, and the carb inlet will still be the same size, so you will not realize any increase in flow or availability of fuel. If your Craftsman with the 17 HP Kohler is a gravity fed fuel system, you may be able to improve the OEM configuration by adding a fuel pump. In lieu of adding a fuel pump, you may try routing the fuel hoses away from any direct heat sources and/or insulating the hoses. If the filter you installed is a much larger automotive type of filter than the OEM Kohler filter, you should be OK in that respect. But if the clear filter you chose is a small one, near in size to the OEM Kohler filter............that could be the whole problem. Kohler engines are very finicky about wanting a Kohler brand filter (and it has to be the CORRECT Kohler filter even then). But if the clear filter you have on there now is much bigger than the OEM filter, it is not your trouble.