weird engine problem

ok, full story is..... i took the boat out for the first time since it being winterized, it ran great! until i shut it off to fish a spot and it wouldn't start back up. i brought it home, and replaced the fuel hose that was cracked so i thought that was it because it started back up and ran great. took it back out a few days later and it wouldn't start. took it back home and replaced the fuel diaphragm and cleaned out the fuel filter. ok, it ran great, went fishing and i fished all day with it, ran to a spot, shut it off, started it back up to go to another spot, shut it off to fish. did it all day, went to start it to go home, turned the key it "popped" like a backfire, and wouldnt start. tried starting it for about 20 min, wouldnt start. about 45 min later tried to start it again ( cause i was using the trolling motor to get back to the boat launch and it was taking forever) and the damn thing started and ran great!!!!! anybody got a freakin clue as to what is going on?????? it will run great, start great and stop great, then all of a sudden it will "pop" while im turning the key to start it (again it sounds like a backfire) and it wont want to start until i do something to it. help!!!

You may get a much better response with key information !-----------What is the model # and pony power of your motor ???

woops, forgot about that part. its a 1984 chrystler force 85 hp.

Start with a compression test.
Then clean the carbs.While they are off check the reeds.
Reset the airscrews at 1 and 1/16th turn out.
Replace all the hoses.
Is the choke working everytime?
Check the fuelpump diaphram again.

how do you do a compression test? i cleaned the carbs out the other day but didnt check the reeds, going to reset the screws and the choke does work everytime. which hoses are you referring too? thank you for the help!

Any fuel line.
Comp: Remove all plugs,ground the spark plug leads.
Open throttle all the way,
Install tester,turn motor over at least 6 times or untill the guage stops going up.
Go on to the next cylinder.

I made a grounding octopus.#2 wire connector,4pieces #10 wire.Strip both ends about an inch.
Put all wires in one end of the comnnector.Smash it so the don't come out.
The other end.Can be soldered or just left alone.
When using,ground out the #2 connector somewhere on the motor.Then put the other end in the spark plug boots.
This stops the pack from going bad.