Motor periodically will not crank

[Hunter91]

I have a 1998 Mercury 225 EFI. I run it just about every weekend. In the past month or so sometimes I go to turn the key to crank it and nothing happens as if it was in gear or something. I can play around with trimming the motor up or down, sometimes this works sometimes not, or just continue trying the key and eventually it will crank. When it cranks I generally have no more problems that trip. It is a very sporadic issue. I have checked all connections, always make sure its out of gear to start. Just thought someone could give me an idea of what to check next if they have had the problem. Thanks.

[fishinwrench]

Battery leads clean and tight?

If so then it's most likely the main harness plug isn't making good contact on the yellow/blk. pin.  Or it could be moisture in the key switch.

I would have said the master fuse link might be dirty/corroded..... but if the tilt/trim works then that is ok.

The main harness plug looks like this, and they are a common source of intermittent problems 

Could also be a bad solenoid.  Do you have a voltmeter, or even a test light handy?

[Hunter91]

Thanks I will check those out.