Bomoboater
New member
The boat is a 1994 Formula 252ss w/ mercruiser 454 carbed (Rochester)b3 outdrive and 425 hours.
Occasionally the motor will stall. There is no sputtering, backfiring, or indication it's going to stall; it just dies as though I switched it off. This has happened at idle, chugging up the channel at 1100 rpm, at speed (3100rpm), and with a cold or hot motor. It's gone weeks without issue, but then happens at the least convenient moment
When it dies at higher rpms the motor quits for a brief moment then springs right back to life. When it dies at idle or low rpm, I can restart it but it will die within a second or two, or as soon as I try to throttle up (in gear). If I put it in neutral and bring the rpms up and rev it up and down a few times it will usually run fine immediately thereafter. I did notice the last time when it died, I could start it, it would die, then a quick turn of the key gave nothing (no starter, no audible click). A 5-10 second wait and the starter would engage properly.
Jiggling the throttle around does not stall the motor, jiggling the key has no effect, same with the kill switch
Some history. I had a strange short the first couple weeks of this season that kept kicking off the ignition breaker. I traced that to a spark plug wire that was never replaced properly by my marina.
The boat starts with difficulty when cold and having sat for 4+ days. Starts easily within 48 hours of use, and when warm
Occasionally the oil pressure gauge gives no reading from start up. Upon the next restart of the motor it springs back to life and operates as normal.
There has never been a buzzer or alarm tripped under my ownership
New within the past year:
Plug wires
Oil/filter
Divorced choke thermostat.
Water pump impeller
Within the past month
Fuel water filter (no water in it, tiniest amount of sediment)
Spark plugs mr43t gapped at .035
Gas - ethanol free 91 treated with marine stabil
I have not yet checked the fuel filter at the carb.
Any thoughts on this? Thank you
Occasionally the motor will stall. There is no sputtering, backfiring, or indication it's going to stall; it just dies as though I switched it off. This has happened at idle, chugging up the channel at 1100 rpm, at speed (3100rpm), and with a cold or hot motor. It's gone weeks without issue, but then happens at the least convenient moment
When it dies at higher rpms the motor quits for a brief moment then springs right back to life. When it dies at idle or low rpm, I can restart it but it will die within a second or two, or as soon as I try to throttle up (in gear). If I put it in neutral and bring the rpms up and rev it up and down a few times it will usually run fine immediately thereafter. I did notice the last time when it died, I could start it, it would die, then a quick turn of the key gave nothing (no starter, no audible click). A 5-10 second wait and the starter would engage properly.
Jiggling the throttle around does not stall the motor, jiggling the key has no effect, same with the kill switch
Some history. I had a strange short the first couple weeks of this season that kept kicking off the ignition breaker. I traced that to a spark plug wire that was never replaced properly by my marina.
The boat starts with difficulty when cold and having sat for 4+ days. Starts easily within 48 hours of use, and when warm
Occasionally the oil pressure gauge gives no reading from start up. Upon the next restart of the motor it springs back to life and operates as normal.
There has never been a buzzer or alarm tripped under my ownership
New within the past year:
Plug wires
Oil/filter
Divorced choke thermostat.
Water pump impeller
Within the past month
Fuel water filter (no water in it, tiniest amount of sediment)
Spark plugs mr43t gapped at .035
Gas - ethanol free 91 treated with marine stabil
I have not yet checked the fuel filter at the carb.
Any thoughts on this? Thank you
