Go back to the basics. Check the ignition timing, its not likely you've got a bad cam gear if its got good compresssion, but the magneto gear doesn't drive anything else other than the magneto and hour meter. Pull the #1 spark plug, bring #1 cylinder up on compression (put your thumb over the spark plug hole to feel compression), check to make sure the magneto rotor is pointing at the right cylinder and the impulse trips just after top dead center. If you have compression and ignition at the right time, then the only other problem can be fuel, either too lean or too rich. On my WD-6, you have to pull the choke all the way out and crank it over a couple turns before it'll even think about firing, then its easy to flood if you don't close the choke right away (needs a carb overhaul, as one of these days its not going to start at all). If it occasionally puffs black smoke, its probably too rich and you'll have to overhaul the carburetor. If it acts like it wants to start with full choke, it may have a vacuum leak somewhere, or you need to overhaul the carburetor (notice the recurring theme). If it puffs white smoke, the diesel injection pump isn't shutting all the way off and is contaminating the fuel mixture with diesel, which will also keep it from firing properly (you do have the diesel throttle lever all the way towards the stop position, don't you?). Good luck, Keith
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