Hi All,

I have a 3.7 Mercuriser Inline 4cyl motor and have noticed an odd
behavior with it. When at the dock or on the trailer with a cold
motor, it will crank and start right up, but when the motor is fully
warmed up it often doesn't want to crank. I've read of others wth
this motor who get vapor lock in a hot engine but I'm assuming these
folks at least get it to crank, whereas mine won't even crank. I
think I hear the click of the solonoid trying to engage when turning
the key and that's all. Vapor lock doesn't prevent the engine from
cranking does it? If I remove the engine cover and allow it to cool
for a while, it usually cranks and starts right up. The cooling
system is closed so the temp sits at 120-140f max. I installed an
electronic ignition kit about 7 years ago and other than that the
motor is stock. Boat runs great once it starts.

Thanks,
Ted

On Mar 19, 9:07*pm, Ted wrote:
Hi All,

I have a 3.7 Mercuriser Inline 4cyl motor and have noticed an odd
behavior with it. *When at the dock or on the trailer with a cold
motor, it will crank and start right up, but when the motor is fully
warmed up it often doesn't want to crank. *I've read of others wth
this motor who get vapor lock in a hot engine but I'm assuming these
folks at least get it to crank, whereas mine won't even crank. *I
think I hear the click of the solonoid trying to engage when turning
the key and that's all. *Vapor lock doesn't prevent the engine from
cranking does it? *If I remove the engine cover and allow it to cool
for a while, it usually cranks and starts right up. *The cooling
system is closed so the temp sits at 120-140f max. *I installed an
electronic ignition kit about 7 years ago and other than that the
motor is stock. *Boat runs great once it starts.

Thanks,
Ted

are you SURE the battery is good? I had a Buick that would do the
same thing. Even in 0 degree weather, it would start first thing, then
drive it for 10 minutes, go to the gas station, get a cup of coffee,
then all it would do is grunt. leave it set for 5 minutes and it would
start like brand new. all indications was that it had to be something
else, but no it was the battery.

Even if it vapor locked, the engine should crank. Its also possible
that the brushes are corroded in the starter not making a healthy
contact on the armature. OR if it is a GM starter from the mid 80's to
early 90's. believe it or not, they had aluminum field coils in them.
eventually they would corrode internally and when hot, they wouldnt'
crank until cool down.

On Fri, 19 Mar 2010 19:07:50 -0700 (PDT), Ted
wrote:

Hi All,

I have a 3.7 Mercuriser Inline 4cyl motor and have noticed an odd
behavior with it. When at the dock or on the trailer with a cold
motor, it will crank and start right up, but when the motor is fully
warmed up it often doesn't want to crank. I've read of others wth
this motor who get vapor lock in a hot engine but I'm assuming these
folks at least get it to crank, whereas mine won't even crank. I
think I hear the click of the solonoid trying to engage when turning
the key and that's all. Vapor lock doesn't prevent the engine from
cranking does it? If I remove the engine cover and allow it to cool
for a while, it usually cranks and starts right up. The cooling
system is closed so the temp sits at 120-140f max. I installed an
electronic ignition kit about 7 years ago and other than that the
motor is stock. Boat runs great once it starts.

Thanks,
Ted

If you're for sure hearing the solenoid and the battery is good, what
about the starter motor? It'd be interesting to see if it'll crank
over when hot using a manual starter switch. Maybe needs a rebuild or
replacement?