sorry no one responded, but it is best to give all of the motors info so others will know what motor you are talking about.
Yamaha has made lots of C90s over the years
you know it has a filter under the cowl already, right?
but if you want to add another one under the splash-well go right ahead.
it will not be in direct sunlight all the time depending on which way the boat is facing to the sun, and you could rig up a piece of plastic or metal hanging down to...
is that no it cannot be done ?
or no you have not done it or tried to do that?
I had no idea they had a unit like that. what does it do when hooked up?
bad connection in there somewhere leads to not enough voltage and current.
does the starter spin the motor faster when you hook the charger to the system?
under load the motor needs more fuel.
make sure the high pressure pump is keeping rail pressure in spec.
I know nothing about your Susuki, but some motors will keep RPM down if there is a failed sensor the ECU needs to be seeing working correctly
