I have a Lazer HP with a 23HP Kawasaki air-cooled engine. It has about 700 hrs on it. I bought it used with 550 hrs, so I don't know how well it was maintained by the last guy. I have 2 other Kawasakis to compare it to, they start up fine hot or cold. Here is the problem. It starts right up in the AM with the choke when it is cold. However, after cutting a lawn, and then shut off for 5 minutes on the trailer driving to the next stop, it takes a long time cranking the starter to get it to run. It finally starts after some choking, but spits out loads of black smoke (unburnt gas from too much choke?). Once started, it runs great. Good power, idles smooth. Normal fuel consumption. Where do I start? Plugs? Valves? Carb? I'm not a mechanic, but I do ok, I am willing to try anything.