1997 Mariner 200 EFI SN OG468820 would intermittently have a rough idle and when you would throttle up at the lake it would bog. This happen last year and I changed all the fuel lines and filter and plugs. It was fine untill a couple days ago and did it again. Got it home and it would barely crank and run and would not throttle up. The Fuel pressure was at 39 psi with the pump running and 36 when not running.I changed the plugs to NGK BUZ8H Resistor plugs from BU8H. I checked the spark with a timeing light on each plug wire and had fire. I then started checking connectors. I unplugged the connector from the ECU to the main harness. It is just a rubber push together connector with long pins. All the pin looked good with no burns. When I plugged it back together it cranked and ran great at home. I took the plug back apart and spread the pin a tiny bit with a knife blade and put it back together and tyrapped the connector together so it could not work loose. It cranked and ran great at home. I guess I am ready to put it in water and try it again. Any thoughts of anything else to check? It is so intermittent I still am a little concerned if that was the problem. By the way it is on a Nitro 896 bass boat with very low hours. I bought it new and did not use it a lot untill I retired last year.
