I have a 4 year old zero turn cub cadet 22 hp kawa that over the past year has started to give me troubles. It started to get hardr to turn over like it was a weak battery. I would charge it every time and it would still have a tough time getting past the compression stroke, sometimes having to give it some help with my hand. It would also take almost a min of cranking for it to finally start with a lot of black smoke for a sec once it did start. Once its running it runs like a dream. Ok so i have been working on it and here is what i have done. I have adjusted the valves numerous times to between .004 and .006, It seems to crank a whole lot better at closer to the .004 than it does at .006 sometimes it still struggles. I have cleaned the carb twice. new gas. new battery. new fuel pump (i broke the nipple off while messing with it so i had to replace it). new plugs. Ive checked for spark and it looks good to me. I even took an old plug and made the gap almost 1/4 in just to see if it would still spark and it did. It seems to be getting plenty of fuel, the air filter bowl area will fill with gas after cranking on it for a while. Sometimes it would backfire through the carb with a flame when trying to start. A few times it would start then immediately die. very rarely it will actually start and it will run just fine. Ive tried starting fluid and still nothing. I know a lot about engines but this has me stumped. Ive pulled the plugs after cranking forever and there not overly soaked with fuel or anything so i dont think its flooding it. It just seems like its not getting spark but it is.
Updates after working on it all day. I have been setting the valve lash at TDC. I have read a few posts where you need to set valve lash at 1/4 in past TDC so i did. It seems to spin a lot better now and starts easily sometimes. But at random times trying to start it whether it be hot or cold it takes a while for it to finally start. But it does start. What else should i be checking?