I'm having some issues with my 1977 Stury with a 470 Mercruiser.
It will run fine most of the day pulling skiers and tubing etc.
I will then start hard and then on one of the pulls with a skier it will pick up a miss and won't get over 3000 RPM's.
It will straighten out sometimes as well.
The problem is the same when it had point ignition and when I changed to the Hot Spark
I've checked the fuel tank and it is clean.
Changed fuel line
Replaced fuel pump.
Replaced carb
Changed fuel filters
Changed over to HotSpark ignition and their coil.
(Checked voltage under way. It is 10.29 volt when it is screwing up and 10.33 when it is running good.
Changed plugs and wires.
Replaced the solinoid
New cap and rotor.
Had it to a dealer. First time I've ever had to take a boat to a dealer as I'm a pretty good mechanic.
They replaced a couple of wires that they thought were causing the problem but it didn't change.
Changing the carburator made it run better when it is running right.
I ran it all weekend with the hatch open figuring it may be a heat related issue and it still picked up the miss.
Problem is that it is intermittent and with no reason.
Any ideas would be appreciated.
It will run fine most of the day pulling skiers and tubing etc.
I will then start hard and then on one of the pulls with a skier it will pick up a miss and won't get over 3000 RPM's.
It will straighten out sometimes as well.
The problem is the same when it had point ignition and when I changed to the Hot Spark
I've checked the fuel tank and it is clean.
Changed fuel line
Replaced fuel pump.
Replaced carb
Changed fuel filters
Changed over to HotSpark ignition and their coil.
(Checked voltage under way. It is 10.29 volt when it is screwing up and 10.33 when it is running good.
Changed plugs and wires.
Replaced the solinoid
New cap and rotor.
Had it to a dealer. First time I've ever had to take a boat to a dealer as I'm a pretty good mechanic.
They replaced a couple of wires that they thought were causing the problem but it didn't change.
Changing the carburator made it run better when it is running right.
I ran it all weekend with the hatch open figuring it may be a heat related issue and it still picked up the miss.
Problem is that it is intermittent and with no reason.
Any ideas would be appreciated.