My 1991 Mariner 60, 3Cyl, 2-stroke has let me down today.
It needed lots of 'fast idle' to get it to start and idle. Once it was warmed up I gave it a run and after about 15 minutes it came to a halt. Despite being warmed up, it needed more 'fast idle' to start it again and it kept happening over and over again - stop, restart, run for a few minutes, stop.
- The fuel primer bulb remained solid.
- There is no water visible in the fuel filter/separator.
- The fuel is less than a week old and it was previously left with the carb drains out and a good dose of carb cleaner sprayed through.
- It revved at 5600 rpm at WOT for ages without any problems, so it wasn't 'bogging'.
- IMHO it stopped slightly more smoothly than if the kill-switch had been pulled.
- It was a bit 'tink-tink-tink' at times as it came to a halt, but that might have been the transmission being back-wound by the prop.
- The overheat warning didn't go off.
This evening I'm going to check the plugs, leads and fuel line, but is there anything else that I could/should check whilst doing so before I start adjusting carbs / timing?
If the mixture is off, does it sound more like too rich than too lean? It needs more air to start and idle, but would all three plugs foul at the same time?
SWMO was on board and now trusts neither engine or boat - hence my aim to get it running well and use it whilst she still won't want to accompany me.