Re: 175 Ocean Runner (1996) Fuel Flow Problem
I am following up to provide "The Rest of the Story" for anyone who may have similar problems to mine.
The mechanic tested the engine and had similar results to mine. He had a used vacuum switch and replaced mine. The alarm ended. He charged me $10 for the switch and an hour of labor, though he spent a couple of hours on it. I was satisfied until I put it in the water. Instant alarm as before.
A few posts on this site (or maybe other sites as I do not remember for sure) had mentioned that these engines do not like aftermarket primer bulbs. When I replaced the fuel line, I replaced the bulb with an aftermarket version, so I purchased an OEM bulb and installed it. The engine ran fine (see note below about priming the fuel system) with no alarm, except that I had to disconnect the bulb to get an initial prime on it and reconnect it to the line after any prolonged period with the engine off.
I then realized, again from a couple of great links, that previously (before I began to repair the fuel restriction) I had an anti-siphon valve. This matter is important as my primer bulb was located above the tank and horizontally connected next to the fuel-water separator. I reconfigured it so it hung more vertically and was located closer to the engine. Hanging more vertically enables the internal valves to function better, especially after I removed the anti-siphon valve and replaced it with a regular brass barb [purchased at the box store]. Problem solved.
So, if you are dropping RPMs (I dropped from 5,500 to 4,500 over a period of 2 months) and/or your check engine alarm signals, and/or your engine is more difficult to start, and/or your primer bulb is collapsing, and/or your engine has begun to smoke more and is burning more oil than usual, start with the following steps: check your anti-siphon valve, replace your fuel-water separator, make sure you have a Johnson primer bulb, check all fuel line connections (consider 2 clamps per connection and use the small ss clamps [in bags of 10 at the box store and 1/8 the price of the marine store], confirm your fuel vent hose is not clogged, and replace the fuel line from the tank to the engine if it is aged.
When you initially prime your fuel line after disconnecting it, some people seem to experience a situation where the check engine alarm will signal. A few people have reported that the alarm stops after operating the engine for a short time on the water (not with muffs). I too experienced this situation when I replaced the primer bulb.
My 175 Johnson (1996) again starts quickly, runs like it is brand new, is giving me 5,500 RPM, and has good even compression from all cylinders. This journey has been more involved than I ever expected, but I am back on the water.
Keep in mind that fuel flow problems and check engine alarms can arise from several issues, and it is possible to add one or two while you are trying to fix the original problem. You need to be systematic as you resolve your alarm.
