I had the lean condition last fall when I bought the boat. Bad fuel clogging the filter and a completely blocked fuel tank vent. Ive only owned the boat since october and it didnt run well then. Just trying to track down the issues by process of elimination and this is where it has led me. I do not know the real history of this motor and am certain I was lied to about the running condition. The price on the boat was good enough that I would have bought it knowing this issue but its frustrating to have to figure it all out from scratch. The other heads available were from a 98 5.0 carbed engine. Ill get these off and decide what to do from there. Thanks for the help. Ill report back after i get them off.
The whole point of electronically controlled fuel injection is to make diagnostics easier. Yes, some tests are needed, but you can check compression and every other physical aspect and not find that the ECT is reading excessively high temperature- this would, BTW, cause the engine to run lean, even if your pump, vent, fuel line and everything else in the fuel system is good and operating normally.
You were lied to, I was too. I would recommend that you assume the engine overheated, which means that you need to look at the raw water pump. If that's badly melted, look up into the cavity above the lower gear case and make sure the plastic part that normally holds the copper tube isn't melted, too. If it is, you'll need to replace it- this is called the 'waster pocket cover'. Also, you have (or had) a piece called a 'shutter' in the exhaust system- make sure it's intact or missing. If it's gone or in bad condition, replace it- any parts or service info requests will require knowing the serial number for the engine, gimbel and outdrive- these should be visible on the stickers on each, or on the flame arrestor cover.
If you don't have a parts list, look here and access it by searching with your serial numbers-
https://public-mercurymarine.sysonl...=GuestNA_KEY=NA_KEY_VALUElangIF=englangDB=eng
