l changed the turn key, the wiring, plugs and battery, it makes a sound when l turn key but its not starting up? cant figure out where or what to check next?

Are you saying you get clicking but the starter does not actually turn the flywheel? If that is the case, you are probably hearing the choke click, not the starter. The engine must be in neutral gear for the starter to work, and there are some cases where there are safety switches that are faulty. Follow the starter wire to the solenoid and jump the heavy cables, but be careful. If the engine cranks over, you know where to look. Good luck

If you are planning to keep this engine for awhile, invest in a tuneup and repair manual. It will pay for itself many times over the life of the engine. Here is a site that sells them:

http://marineengine.com/parts/parts.php

does the starter motor spin?

does it engage the flywheel & spin it at a normal rate of speed?

Solenoid clicks but the starter do not spin, measure the voltage at the starter terminal with key turned to ''start''.

If it is at least 12 volts, repair or replace the starter.

Bad voltage at the starter, disconnect, clean & reconnect all the cabling battery to solenoid to starter. They must be bright & tight.

Solenoid clicks but bad voltage at starter, replace the solenoid.

Bad voltage at the solenoid (small terminal with yellow/red wire), troubleshoot keyswitch, neutral safety switch & wiring.