dogdaysllc
Cadet
- Joined
- Aug 31, 2018
- Messages
- 9
I recently bought a pontoon boat with a 2004 Mercury 40HP 4-stroke EFI Bigfoot motor. I did not seatrial the boat, only ran it on muffs. It ran rough and the owner told me the lower unit needed resealing. I paid for the boat/motor accordingly. Upon bringing the boat home, I drained the lower unit and the fluid was yellow/white indicating water intrusion as the owner stated. I refilled the lower unit, changed the plugs and external fuel lines. It still ran rough so I brought it to my local Mercury dealer for a diagnosis. They pressure tested the lower unit and said it held pressure overnight. They thought the water could have been from condensation from running at low speed or from a leaky washer in the fill plug. They changed the oil and timing belt and the motor does, in fact, run smoothly now. They said the compression is good on all 4 cylinders (between 92-95) and that the motor has 637 running hours. So far, so good. They did, however, say that the charging system is not working and that it needs a new stator and rectifier ($$$). They also said the exhaust is clogged and that the powerhead must be pulled to unclog it. The motor does pump water well however I did notice that the water never seems to get warm when being run on the muffs. Finally they said it should have a new thermostat installed. I paid the bill for the diagnosis and brought the boat back home. This brings me to my questions. First, how would I go about testing the electrical output before I go ahead and spend the money for a new stator and rectifier? Second, if the exhaust is, in fact, clogged, is there a way to unclog it without removing the powerhead? If not, how difficult a job is it to remove the powerhead? Should I start with replacing the thermostat first to see if I can get the water from the telltale to come up to temperature?
Thanks!!
Thanks!!