Hi all,
I have twin Merc 7.4L LX MPI Bravo 3's & am having three issues with only the port engine.
First, I typically travel about 45 mins running time to a mooring & spend several hours. When leaving the mooring field & accelerating to planing speed, the port engine stalls. It only did this 2 times all last season, but it's done it twice already this season. Sometimes I have to let it sit for a minute or two because it won't restart, reminding me of a flooded carburetted engine.
Second, starting this season, twice while coming back into the harbor & slowing down to idle speed, the port engine started surging once I throttled down to idle. Shutting off the engine & restarting seemed to cure it.
Third, sometimes at planing speeds when hitting the water coming off a wave, I can see the port tachometer drop sometimes down to zero for less than a second before bouncing back up. I can also hear & feel the drop if it lasts long enough so I know it's not just the tach.
My initial thoughts on the 1st two problems was possibly water in the fuel. I changed fuel filters in the spring & it doesn't make any sense why it would only be the port engine. Note that there's a single fuel tank. My second guess is that there might be a loose or bad electrical connection somewhere, but I'm not sure where to look.
Any suggestions appreciated. Thanks!
I have twin Merc 7.4L LX MPI Bravo 3's & am having three issues with only the port engine.
First, I typically travel about 45 mins running time to a mooring & spend several hours. When leaving the mooring field & accelerating to planing speed, the port engine stalls. It only did this 2 times all last season, but it's done it twice already this season. Sometimes I have to let it sit for a minute or two because it won't restart, reminding me of a flooded carburetted engine.
Second, starting this season, twice while coming back into the harbor & slowing down to idle speed, the port engine started surging once I throttled down to idle. Shutting off the engine & restarting seemed to cure it.
Third, sometimes at planing speeds when hitting the water coming off a wave, I can see the port tachometer drop sometimes down to zero for less than a second before bouncing back up. I can also hear & feel the drop if it lasts long enough so I know it's not just the tach.
My initial thoughts on the 1st two problems was possibly water in the fuel. I changed fuel filters in the spring & it doesn't make any sense why it would only be the port engine. Note that there's a single fuel tank. My second guess is that there might be a loose or bad electrical connection somewhere, but I'm not sure where to look.
Any suggestions appreciated. Thanks!
