jmanteu1
Member
Hello boat experts-
Im not an expert and maybe an advanced novice at best. I think im getting close to solving an issue that my mechanic has not been able to solve and I wanted to bounce this idea off the group. I have twin Mercruiser 350 MAG MPI engines in my 2001 SeaRay Sunsport 280. I generally have the mechanics at the local marina do my winterizations, oil changes, and spot maintence, impellers etc and they do a good job. This year they left one of the drain plugs out of the starboard engine block and i didn't realize it until I had driven back to my marina about 6 miles away ~ 20 min ride. I figured it out, let the mechanic know and he gave me a plug and that solved the issue of the water coming out of the engine.
I went to take it out for a ride about a week later, first ride since driving home from the marina and after putting the plug in and my starboard engine was not getting the power I typically need to take off, port engine performance normal. Typically I go up to about 3500 RPM to get it on plane relatively quickly and back down to 2900 RPM to cruise. The starboard engine almost WOT only gets to 3100 - 3200 RPM max, the port engine helps get it on plane and I can still cruise but the throttles for the two engines are bout 2 inches apart when typically they would be just about even.
Told the mechanic about the issue, drove it back to them, they cant figure anything out, compression testing normal, fuel pressure equal at the rail in both engines (not sure the exact pressure numbers - but equal in the good and poor performing engine) new distributor cap and wires not helping, no error codes showing when testing. When the boat is in neutral I can get 4000 RPM easily on both engines with the same amount of throttle.
After doing some more searching, on this forum I saw some older threads about possible damage to the exhaust rubbers and flappers and to check those if you run the boat with engine block drain plugs out as they can warp or melt with heat.
I went back to the boat today and I have a captains call for the exhaust and I was thinking if the boat performs well with the captains call option, the main exhaust system must be the culprit. I fired it up and hit the captains call and initially it was working on both sides, and then the starboard engine just shut off. Fired up again and hit the captains call switch and it killed the motor again, tried one more time and same thing, each time it will run without stalling until I hit the captains call switch. When I have the normal exhaust system operating I think I hear a little extra clanking on coming from the starboard side exhaust... so im thinking there was some damage there and I have some partial obstruction and needs to be taken apart and inspected.
As I understand taking the exhaust apart is not something that should be done while the boat is in the water, is that correct? Am I correct in my thinking that a partial obstruction to the exhaust would cause poor performance of the engine, ala my low power, low RPM issue?
Thanks in advance for any thoughts on this-
Jake
Im not an expert and maybe an advanced novice at best. I think im getting close to solving an issue that my mechanic has not been able to solve and I wanted to bounce this idea off the group. I have twin Mercruiser 350 MAG MPI engines in my 2001 SeaRay Sunsport 280. I generally have the mechanics at the local marina do my winterizations, oil changes, and spot maintence, impellers etc and they do a good job. This year they left one of the drain plugs out of the starboard engine block and i didn't realize it until I had driven back to my marina about 6 miles away ~ 20 min ride. I figured it out, let the mechanic know and he gave me a plug and that solved the issue of the water coming out of the engine.
I went to take it out for a ride about a week later, first ride since driving home from the marina and after putting the plug in and my starboard engine was not getting the power I typically need to take off, port engine performance normal. Typically I go up to about 3500 RPM to get it on plane relatively quickly and back down to 2900 RPM to cruise. The starboard engine almost WOT only gets to 3100 - 3200 RPM max, the port engine helps get it on plane and I can still cruise but the throttles for the two engines are bout 2 inches apart when typically they would be just about even.
Told the mechanic about the issue, drove it back to them, they cant figure anything out, compression testing normal, fuel pressure equal at the rail in both engines (not sure the exact pressure numbers - but equal in the good and poor performing engine) new distributor cap and wires not helping, no error codes showing when testing. When the boat is in neutral I can get 4000 RPM easily on both engines with the same amount of throttle.
After doing some more searching, on this forum I saw some older threads about possible damage to the exhaust rubbers and flappers and to check those if you run the boat with engine block drain plugs out as they can warp or melt with heat.
I went back to the boat today and I have a captains call for the exhaust and I was thinking if the boat performs well with the captains call option, the main exhaust system must be the culprit. I fired it up and hit the captains call and initially it was working on both sides, and then the starboard engine just shut off. Fired up again and hit the captains call switch and it killed the motor again, tried one more time and same thing, each time it will run without stalling until I hit the captains call switch. When I have the normal exhaust system operating I think I hear a little extra clanking on coming from the starboard side exhaust... so im thinking there was some damage there and I have some partial obstruction and needs to be taken apart and inspected.
As I understand taking the exhaust apart is not something that should be done while the boat is in the water, is that correct? Am I correct in my thinking that a partial obstruction to the exhaust would cause poor performance of the engine, ala my low power, low RPM issue?
Thanks in advance for any thoughts on this-
Jake
