93tige350magski
Recruit
- Joined
- Jul 7, 2013
- Messages
- 3
Hi:
New to the forum and hoping you can help me out with an issue I am having. I have a 1993 tige inboard ski boat with a Mercruiser 350 Magnum Tournament ski engine. I am the original owner so I know the history.
Last season boat was running rough at the end of the year so I figured time for a tune-up. I proceeded to winterize as the freeze was coming and gathered up the parts for the spring.
This spring replaced Cap, rotor, plugs, wires, water separator, Rotor was very difficult to remove. Corroded on the shaft, Used a dremel tool to cut it off in pieces. Changed oil, and started up and ran great in the driveway. Also replaced water pump impeller and the thermostat. Had been running cold in previous season and I found a stuck thermostat.
I have not used the boat much this season, but it seemed to be running ok on the initial launch. Thought I had cured last seasons issues. Here is where the issue comes in. This morning, went for what ended up being a short ski.
After first skier, engine started to backfire through the carb. We headed in,. Had a difficult time getting the boat going, but made it close to the dock and then it stalled and could not get it going again. At the dock, tried to start with no success. Went to get some tools and came back about 15 min later. Was able to get it started after a little cranking and throttle. Checked the timing and it was a 6 deg BTDC. I adjusted it to 8 per the recommendation. Pulled all the plug wires, both ends and the coil wire. Did not find anything obvious. It seemed like it might have been running a bit better. Idled ok and could take throttle when in neutral.. Headed out and after about 5 min of driving, started to lose power and develop the backfire again. I head back in to avoid paddling again. It never stalled on me this time. Even when I initially went out in the morning, It seemed as though I had lost a lot of top end. Sounds like it is working hard, but can't get past 38 mph or so. 42 to 44 is what was normal in the past, although at the end of last year, I don't think I was getting that either, thus part of the reason for the tune-up. Engine does not hit peak rpm.
Decided to pull the plugs, but they all looked a nice tan color. No signs of fouling, even though it seems as though it has a slight miss at times. Went back out. This time, after about 5 min or so, started to lose power again. Does not seem to have any desire for full throttle. Just kind of sits at the same speed where in the past it used to really kind of kick in (carbs opening all barrels I think). Maybe something else. I started to read some of the various threads. I have a thunderbolt IV ignition with the module as best I can tell mounted on the outside of the distributor. The sensor is inside (I did not replace that part). Since it runs and has spark, I can't find any other trouble shooting to go after. I have not done anything with the carb. It has always ran fine and I figured last season was more ignition related so I went with the tune-up parts.
ok. Enough ramble. Wanted to give as much background as I could. Engine has just shy of 600 hours at the moment. Any help in things to check/rule out would be greatly appreciated. Trying to avoid a rash of part swapping.
New to the forum and hoping you can help me out with an issue I am having. I have a 1993 tige inboard ski boat with a Mercruiser 350 Magnum Tournament ski engine. I am the original owner so I know the history.
Last season boat was running rough at the end of the year so I figured time for a tune-up. I proceeded to winterize as the freeze was coming and gathered up the parts for the spring.
This spring replaced Cap, rotor, plugs, wires, water separator, Rotor was very difficult to remove. Corroded on the shaft, Used a dremel tool to cut it off in pieces. Changed oil, and started up and ran great in the driveway. Also replaced water pump impeller and the thermostat. Had been running cold in previous season and I found a stuck thermostat.
I have not used the boat much this season, but it seemed to be running ok on the initial launch. Thought I had cured last seasons issues. Here is where the issue comes in. This morning, went for what ended up being a short ski.
After first skier, engine started to backfire through the carb. We headed in,. Had a difficult time getting the boat going, but made it close to the dock and then it stalled and could not get it going again. At the dock, tried to start with no success. Went to get some tools and came back about 15 min later. Was able to get it started after a little cranking and throttle. Checked the timing and it was a 6 deg BTDC. I adjusted it to 8 per the recommendation. Pulled all the plug wires, both ends and the coil wire. Did not find anything obvious. It seemed like it might have been running a bit better. Idled ok and could take throttle when in neutral.. Headed out and after about 5 min of driving, started to lose power and develop the backfire again. I head back in to avoid paddling again. It never stalled on me this time. Even when I initially went out in the morning, It seemed as though I had lost a lot of top end. Sounds like it is working hard, but can't get past 38 mph or so. 42 to 44 is what was normal in the past, although at the end of last year, I don't think I was getting that either, thus part of the reason for the tune-up. Engine does not hit peak rpm.
Decided to pull the plugs, but they all looked a nice tan color. No signs of fouling, even though it seems as though it has a slight miss at times. Went back out. This time, after about 5 min or so, started to lose power again. Does not seem to have any desire for full throttle. Just kind of sits at the same speed where in the past it used to really kind of kick in (carbs opening all barrels I think). Maybe something else. I started to read some of the various threads. I have a thunderbolt IV ignition with the module as best I can tell mounted on the outside of the distributor. The sensor is inside (I did not replace that part). Since it runs and has spark, I can't find any other trouble shooting to go after. I have not done anything with the carb. It has always ran fine and I figured last season was more ignition related so I went with the tune-up parts.
ok. Enough ramble. Wanted to give as much background as I could. Engine has just shy of 600 hours at the moment. Any help in things to check/rule out would be greatly appreciated. Trying to avoid a rash of part swapping.
