2009 mercruiser 4.3mpi hard start when warm

[Don S]

Re: 2009 mercruiser 4.3mpi hard start when warm

I have bravo drives and have also come to the conclusion if i open the engine hatches right away from a hot run they will start no problem at any time. I have to find a way to get more air in the compartment.

Getting more air in is one thing, getting the hot air out is another. Don't forget, hot air rises, so you want some vent as high as possible.
Maybe a new blower or two installed high in order to suck the air out, with cooling air coming in low. Your standard bilge blowers are probably ducted low in the bilge to pull out fumes, and this also pulls out the cooler air.
The hull itself is also cool because it's sitting in the water.

 

[myentourage]

Re: 2009 mercruiser 4.3mpi hard start when warm

Getting more air in is one thing, getting the hot air out is another. Don't forget, hot air rises, so you want some vent as high as possible.
Maybe a new blower or two installed high in order to suck the air out, with cooling air coming in low. Your standard bilge blowers are probably ducted low in the bilge to pull out fumes, and this also pulls out the cooler air.
The hull itself is also cool because it's sitting in the water.

I have 2 rule blowers blowing air right to the flame arresters because the sucking air out wasn't working. Should i add more blowers? I already have 2 rectangular vents up high under the gunwals.

 

[Don S]

Re: 2009 mercruiser 4.3mpi hard start when warm

The flame arrestor is not where it should be aimed. There is only air there, not fuel. You need cooler air coming in from the bottom while another blower sucks air out of the compartment.