Hi all, I just tried to do the blade change on my MacKissic 12PT9 shredder-chipper, using Liquid Wrench, WD40, a Bernzomatic torch, and a Sears Craftsman 3/16ths hex socket. The first screw came out OK after repeated effort. The second screw rounded off in the hex hole and most certainly will have to be removed with a screw extractor, if that is even possible. I suspect it was at least partially rounded in the factory assembly, because I didn't apply a lot of effort to round it. The third screw broke my Craftsman 3/16ths hex socket, which our local Sears cheerfully replaced for free. All three screws had the benefit of Liquid Wrench penetrant, WD40 penetrant, torch heating, and hex torquing with simultanous hammer tapping. They all should have come out with less difficulty than the first one did. The rounded second screw is particularly worrisome, because I have visions of my screw extractor breaking off as easily as the hex socket did on the third screw. It would be essentially impossible to remove the screw with a broken extractor in it. In that case, I might be looking at a flywheel replacement. My recent experience corroborates the problems others have reported. This has been an eye opener for me. This blade replacement is way more difficult than it should be. I suspect it is symptomatic of a design flaw, and I intend to contact MacKissic about this matter. I'll keep you posted. MM

The question was posed in 2009. It's now 2019. I expect most prolly everyone solved their problem by getting a new lawmower. But since you are here.... I have a hand-me-down Craftsman with a 16.5HP Kohler engine. After I changed the fuel filter the thing started stalling out on hills, etc. Same places. Same everything. It drove me nuts so I came to places like this for a clue. IF you are having the stalling problem after changing the filter...get the right filter. Heck, I went to a local mower shop to get the right filter and the owner refused to sell me one. Said I had the BEST filter already. Jeez. So I went elsewhere and got the right filter....same as the one I replaced and today...no problems. This is not all good bekez I had a new Cub Cadet all picked out. Dang! Listen...the right filter is on Amazon. So if you messed up like I did and got the one they said would work...the larger one...then go back to the smaller one: Kohler Engines 25 050 21-S Fuel Filter If you can't find it by the number...get one that looks like it and fits the Kohler. Just that simple. Good luck! My good deed for the day.

Thanks engine tech. Heres what I did. Started with the original coils with all wires hooked up. Started engine, pulled the coil wire off the left plug (presumable the bad coil I thought), the engine remained running. Plugged the wire back to the plug, Pulled the coil wire off the right plug and the engine died. Unhooked the kill wires and the same thing happened. Swapped the coils, started the engine, pulled the coil wire off the right plug and the engine remained running. Plugged the wire back up, Pulled the coil wire off the left plug and the engine died. Same thing with the kill wires hooked up. Put the new coil on the left side. Unplugged the kill wires. Started the engine, unplugged the right plug wire and the engine died. Now here is something interesting, I noticed that the new coil was arcking from the boot to the metal engine cover. Thats where I got the shock from the previous post. I stopped the engine and unplugged the left plug wire and refired engine and it ran. Noticed that just plugging up one kill wire(to either coil)will not stop engine. But when I plug them both up the engine dies. I can move the plug wire and hear the engine change, like it starts firing the plug. Sorry about the long post. Thanis again.

There is only ONE adjustment screw and that is supposed to be for IDLE only. I do not engage mower blades at IDLE, only at higher RPM. The new coil is junk. Will have another new coil Mon or Tues. Now have intermitent spark on one side, weak spark on other side. Old coil is corroded through in one area. I'm still trying to figure out how most are saying it's a carb mixture problem when there is nothing to adjust, and idle speed isn't the problem. I still say it's the coil...we shall see. All this trouble over this engine and not getting much gardening done! Invested a lot in this machine. New blades, belts, engine parts, plus a new cultivator and hitch system. I need it to be working....just only so much I can do with little money. Very exasperated now. Neighbor down the road has 2 MTD riders for $50. Or 1 1/2 rather. Engines are different but still Briggs. No idea how bad those are...or if one of those would even mount since they are single cylinder and mine is a twin. 16 hp on the one I believe. Thanks for bearing with me on this and your suggestions.