No Start When Hot????

[67Bertram]

So....I have been restoring a 67 Bertram 20 with a Merc 190 HP 470. After fixing almost everything, I am down to one last problem. Boat starts and runs great. Go for a 15 minute cruise, shut her down and then I have a hard start condition. This happens every time the boat is hot. The engine cranks , but the only way I can describe it is that it feels like a weak battery or a timing issue (which it is not) It cranks slow...and does not fire easily at all. After several attempts it does kick over. Normally though the boat kicks in one click. I don't think this is vapor lock since it cranks abnormally. It is not that it just wont start, it is more like it cranks really weird and is hard to start. Is this the sign of a dying starter? Thoughts?

 

[nola mike]

Someone retrofitted a '67 with a 470? Could be a weak starter, but next time it happens pull your plugs and turn the engine over. These engines can leak from the mani/riser into the #4 cylinder. The resulting water in the cylinder can cause those symptoms. Also, once you get it restarted, if you let it run for a minute, shut down and restart, what happens?

 

[alldodge]

Could be a starter, cables, timing and other things. My first thought is the timing is off. Has anything been done to the motor?

 

[kenny nunez]

In addition to the above posts there are 2 things that come to my memory on these engines.
#1, If you still have the old style Prestolite starter those things are bad news. The replacement was a Delco with the top mounted solenoid and required a mounting kit that probably is still available from Mercruiser.
#2 , Make sure that when trying to start the by pass circuit is supplying 12 volts to the + side of the coil. That is the wire from the I or R primary stud on the solenoid which is the one next to the stud with the yellow/red stripe.