Hey Jim, I got your name from a friend who says you are the man when it comes to diagnosing issues with your boat. I have a 1990 PCM 351 powerplant that I've owned for over 20 years and she's never given me a lick of trouble. This year when I put her in the water, I had MAJOR hard starting issues. I would crank and crank the engine and it would finally fire and die. this process repeats several times and eventually I would get it started after raising my engine cover, taking the flame arrestor loose and inspecting the carb and linkage, choke position etc. It's like magic, it just happens to start.
I was beside myself... and started replacing parts. My boat is like a part of our family and I was willing to do whatever it took to get old faithful (not any more) running again. Well here is the list of things I replaced in an attempt to get it to start quickly and reliably again: Coil (from an autopart store), plugs, wires, distributor cap, rotor button, condensor, and points (all purchased from skidim for the correct year and motor) all of these parts had NO AFFECT on my starting problem. Then I went to the fuel source: purchased from skidim new Holley 4160 marine carb, fuel line, fuel/water seperator, flame arrestor, and mechanical fuel pump. Installed all the above and I still have the EXACT problem starting my engine. All those parts and still have a problem starting the engine. I will throw this in there... it does SEEM to start a little easier cold than when I've been running around the river for a couple of hours pulling a skier or wakeboarder. When I lift up the engine box, the manifolds are very warm but my temp gauge is saying my circulating water temp is around 150-160 degrees and I put a brand new impellor in this spring after reading some threads on vapor lock.
I've tried everything and I just can't seem to land upon the root cause for the hard starting. It fires up and dies, fires up and dies. I pump the throttle several times and it fires and dies again... eventually like I said before it will eventually start but I feel like I'm going to wear my starter out and certainly I'm wearing my patience out!
Please help and I hope I have given you enough information for you to give me a good diagnosis. I feel like I have replace EVERYTHING that can possibly be replaced...
Thanks for your time.