BUP

iTrader: (9)

a real reading of 12 psi on most marine carbs the needle in the seat will not hold dumping a chit load of fuel and possible engine hydro lock can take place especially at start up.

Matter of fact 12 psi on basically stock carb and engine apps at start up with real 12 psi fuel pressure will hydro lock the engine.

with that said lets ask how are you testing your fuel pressure and with what gauge or tool and where ( location ) are you hooking it up at ?

Take your boats fuel tank out of the mix and use a portable outboard fuel tank 6 gallons with fresh fuel and new fuel line with a primer bulb - if the engine starts to die squeeze the primer bulb - did anything change ?

next take fuel pressure readings with this set up - what is it at idle speed and at 2500 rpms and at 3500 rom and at fuel throttle ?

No way your basically stock marine carb can support real 12 psi fuel pressure.

Have you tested for spark with inline sealed spark checkers especially right after at non forced engine shut down ? Does your kill lanyard work properly and hooked securely ?

BUP

iTrader: (9)

what fuel pump do you have - and its set up . is the fuel pump a new install ?

cmattj

The Overboard kill lanyard on my 97 was building resistance due to its slide pole design and killing spark unless cooled for a time.

I went to the coil after it died with a old school alligator jumper wire and fired right up and took me back safely.

Reach around and bypass the kill switch at dash or shifter. As it controls ignition feed directly after the main ignition switch.

I only found it at point of failure . So you may have to wait until it fails again and go after it like BUP stated.

. Intermittent problems are $$ because we tend to throw alot of parts at things..

Scarab2222

Fuel pump is on the block. The pressure gauge is on the fuel rail just under the carb. The first time it died i had no spark but the second two times it fired right back up so i didnt check. There is no gas spillage or leakage anywhere.

Scarab2222

And at idle it has a pressure of like 8-10

Scarab2222

Yea i cant seem to fix it cause it never seems to be broke at the right time

AllDodge

iTrader: (1)

Need an inline regulator to get the pressure down a bit

cmattj

They never are.. But prepare so your ready to diagnose it once it fails. Bring wire jumpers and Checkers as mentioned by BUP.. Once its at it point of no spark. check it.. Jump the coil from a known 12v source and you'll be on your way to finding it.

I agree the fuel pressure is borderline pushing the needle and seat so that will have to be addressed as well but proper inline gauge will tell you. Fuel pumps also have a internal bleed off that run to the carb in the event of failure so it wont leak in the bilge. that would give you a flooded sensation easy to feel. Stay on the lack of spark repair but get your fuel pressures down soon.

Scarab2222

The fuel pump is not vented to the carb it just has a cap on it. How do i jump the coil and what does that tell me?

cmattj

If at the point of failure ( crank but no start) check to see with key on you have 12 volts to coil .(white or red wire maybe both together) with your checker. If you have 12volts but it still wont start the remove your coil wire and put the spark checker in and ground it. im not sure what color your dist wires that trigger the coil are but if with key on you touch them to ground quickly and the spark checker fires. its probably the sensor or modual breaking down when hot inside the distributor.

If there is no 12volts reading at the coil with key on "during the failure". thats where the jumper wire comes in.

From a know 12 volt source (battery) use the jumper wire to power the coil and check the items again. If she fires up remove the jumper to determine if the ignition switch which goes through the saftey laynard is building heat and breaking down. In that case put a new igntion switch and replace the safety laynard switch. Bring the items with you if you cant get it to fail at home on the hose or idling on the water.