I have an older Mercury 9.9 (2-stroke), which I had worked on when I bought it (with the boat). After having it serviced, it's always been great. Until this weekend. Started it, let it idle for a couple of minutes and then dropped our mooring. As soon as it had any throttle it would stall. Ended up having to drop anchor in our mooring field so we wouldn't end up on-shore or hitting another boat. One thing I noticed is that the tank (slightly old premium gas) under quite a bit of pressure. I took the cap off the external tank and it let out a lot of pressure.
It was a lot warmer than normal here this week (90 deg instead of 70s). I'm wondering if all the tank pressure was the culprit. Normally we attach the line to the motor, pump the bulb until it's firm, hit the choke and fire up the engine. It always starts on the 1st or 2nd pull. Then take the choke off and let it idle while we're setting up. We may have rushed things a little this time, not letting it idle for more that 2-3 minutes, but that's the only different thing, other than the pressure in the tank.
Once I got it restarted (~ 10 pulls and messing with the choke) it seemed fine. We were able to slowly motor around the mooring field for a while until we felt confident it was running ok. Then went out for a sail. When we're day sailing we leave the external tank attached and just use the kill switch when the sails are set. When it was time to come in, it started on the 2nd pull. Normally it's the 1st.
I'm not sure what the cause of the initial failure was -- wondering if it was the fact that the tank had a lot of pressure in it and was sending too much fuel to the engine, flooding it. I'd like to head it off though -- we're on a mooring and can't sail into or out of it. If I need to service the engine, I'd need to row out and remove the motor. Then again, it could be the fuel. It's from the fall. Though it was premium, non-ethanol and had some sta bil in it, which has always worked for me in the past.
It was a lot warmer than normal here this week (90 deg instead of 70s). I'm wondering if all the tank pressure was the culprit. Normally we attach the line to the motor, pump the bulb until it's firm, hit the choke and fire up the engine. It always starts on the 1st or 2nd pull. Then take the choke off and let it idle while we're setting up. We may have rushed things a little this time, not letting it idle for more that 2-3 minutes, but that's the only different thing, other than the pressure in the tank.
Once I got it restarted (~ 10 pulls and messing with the choke) it seemed fine. We were able to slowly motor around the mooring field for a while until we felt confident it was running ok. Then went out for a sail. When we're day sailing we leave the external tank attached and just use the kill switch when the sails are set. When it was time to come in, it started on the 2nd pull. Normally it's the 1st.
I'm not sure what the cause of the initial failure was -- wondering if it was the fact that the tank had a lot of pressure in it and was sending too much fuel to the engine, flooding it. I'd like to head it off though -- we're on a mooring and can't sail into or out of it. If I need to service the engine, I'd need to row out and remove the motor. Then again, it could be the fuel. It's from the fall. Though it was premium, non-ethanol and had some sta bil in it, which has always worked for me in the past.