1997 Saltwater Series II fuel from exhaust

[grady208]

1997 Saltwater Series II 175 - S175TXRV starts easily and runs great across RPM range but at idle is spitting some fuel from the rear exhaust ports. I have changed the low pressure pumps, changed primary and secondary filters. Can prime the bulb to hard before start. Fuel filter bowl on engine will fill up, but after 15-20 seconds of idling, the filter bowl empties and symptoms start. No obvious air leaks. Any thoughts?

[DennisG01]

1997 Saltwater Series II 175 - S175TXRV starts easily and runs great across RPM range but at idle is spitting some fuel from the rear exhaust ports. I have changed the low pressure pumps, changed primary and secondary filters. Can prime the bulb to hard before start. Fuel filter bowl on engine will fill up, but after 15-20 seconds of idling, the filter bowl empties and symptoms start. No obvious air leaks. Any thoughts?

Please clarify some more. If the engine-mounted F/W separator empties, then the engine CAN'T run great across the RPM band.

[99yam40]

what fuel is hitting some cylinders is not being burned,
spark to one or more cylinders is not hitting at idle
or there is too much fuel hitting one or more cylinders keeping the spark from properly burning in that cylinder.
Or you have a leak, but if it is coming out of the exhaust it has to be coming from inside the motor.

might check to make sure those 3 new fuel pumps are not leaking fuel into a crankcase

[DennisG01]

Oh... pull your spark plugs and "read" them. You can google for how to do that - there's plenty of info out there on that and easy to find. This can tell you what's going on in the cylinders.

[grady208]

Thanks guys. This was a problem before I changed the pumps so I am assuming the new pumps are ok.

Dennis has a good point and I should go out and run it and see what it does. I only noticed the fuel dropping in the filter bowl after I changed the pumps and that didn't fix the issue.