500efi backfired?help needed
 

bought used boat, when running on hose ,cold natured, not much throtle responce, blip throtle off idle to about 1500 backfired up into intakewater temp was around 130-140,what do you think?
thanks rob

possibly injectors need cleaned.
possibly timing needs set.
possibly needs plug wires.

Most likely just needs a new water separator filter and a tank of fresh gas run thru it.

M

hopefully it's not a worn cam lobe due to a stuck exhaust valve like i just had.:mad:

it ran fine friday but sat poping up in intake , down on power, want rev past 3800,other motor is ok,they washed the engine compartment may have water in something,any sugestions anybody????????

Theres youre answer Rob!! Water in the electroics!!!! Try WD40 on all connections & around wires ....Should fix ya right up!!!

Birddog is right. Just remove distributor cap and spray some water displacing stuff and you will be good to go.

BT :cool:

cked the dist was dry,ck all conections ecept the ecu willtry next,the swap the ucu with other motor, ran merc scan tool no codes,replacing plugs ,caps ,rotors ,water seperators tonite see what happens,it was poping trying to get on plane just on one motor,other was fine,motors have 50 hours,has fresh gas with heet and fuel injector cleaner in it,new boat blues?

Do a compression check before you replace all that stuff if you havent already