hello,when i turn the key the motor will just crank and crank till i let go of key then it will start or try to start?? i put a new key switch in but still does this any ideas?

Let's start with the basics: air fuel & spark. Does it have all of the above? Miss any one of the above and you get a no start.

yes it has all the above,it will start if i let the key go but will not start if im holding the key all the way to right

Kill switch?

What type of ignition system do you have? I've seen some boats with an automotive style ignition system installed where 12 volts is run directly to the coil for starting only (gives a hotter spark) then when the key is released from start to run the power to the coil runs through a resistor to lower the output of the coil and prolong it's life. If you have a system like this it is possible to have a short or broken start wire but still run through the resistor in the run position. However as I stated before it depends what type of ignition system you are using. The coils on my boat are designed to run on 12 volts all the time and don't use a dropping resistor.

Check the wire that runs from the starter solenoid to + side of the coil. It's ONLY HOT WHILE CRANKING and provides a full 12 volts to the coil while cranking. Merc wiring used a purple-yellow wire for this. After you release the key from the start position the coil then gets it's power through a resistance wire which sounds like it is OK.

A little more info would be helpful like what engine-year-carb-fuel injection-ignition type.

Um, that's the way it's supposed to work. The far right (clockwise) position is "Start." "On" is when you let go.

ya, but it supposed to start when you hold all the way to right i know im no explaining it vary well ,,lol just think of as trying to start your truck and turning the key and it wont start till you let go of key,its a 454 merc with330hp thunderbolt ini,all new coil,pick up in dis,new key switch ,,,245 ltd chris craft,300 hr

1989 sorry..

Does it start and stay running after you let go of the key?

if it does check the I on the starter solenoid for power when the key is in the crank position,that wire feeds the coil when cranking then the module switches over to the purple wire..if it dies after you let go of the key then replace the module..bur first check that you are getting power to the coil and the module's purple wire..