Got my boat with the 2007 90HP E-TEC back in the water after various maintenance projects, which included a rebuild of the water pump (including new impeller). I did this because the engine is fairly new to me and I didn't know how long it had gone since such service, and also because the engine wasn't "peeing" a vigorous amount of cooling water from the outflow. A friend with E-TECs said it should be gushing pretty well, while mine was more of a trickling stream -- steady but meager. Plus, he noticed that while my outboard was idling at the dock, exhaust was bubbling up from underwater, rather than coming out the same outflow as the cooling water, as he said it should when idling.
Now that it's back in the water after the water-pump rebuild, neither of those issues has changed. Another friend suggests flushing the engine with Salt-Away to improve the water circulation and perhaps unplug the exhaust system. Good idea? Other suggestions? I'm on a remote island without mechanics handy, so I'm doing my DIY best. Thanks for any tips.
If you notice excessive bubbling from below, split the side covers to expose the idle relief port and remove the six fasteners holding it to the exhaust housing. Check the exhaust filter for carbon and clean or replace it.
Chances are no one ever replaced the muffler filter which is a required item for every 300 hour/3 yr. service.
"There is never just one thing wrong with a boat";
-- Travis McGee, main character in a book series by John D. McDonald
The factory recommends that a properly trained technician service your Johnson or Evinrude outboard motor. Should you elect to perform repairs yourself, use caution, common sense, and observe safety procedures in the vicinity of flammable liquids, around moving parts, near high-temperature components, and working with electrical or ignition systems.
The information offered here is only general in nature and should not be construed as complete factory approved procedures, techniques, or specifications. Always use the proper service manual for your motor, up-to-date service literature, the correct tools, and have an understanding of how to proceed with troubleshooting and repair methods. If you are unsure or uncomfortable with a procedure, a situation, or a technique, enlist the services of a factory trained technician.
OK, thanks to both of you. I'll try replacing the muffler filter and see if that stops/reduces the bubbling at idle. Would a clogged muffler filter also be restraining the cooling water outflow? Are they the same passage?