1995 Johnson 175's

[Joe Reeves]

1 - The oil tank sensor? I've no idea of its circuitry. If beeping when it's not supposed to be beeping, and it stops beeping when I disconnect the ground wire... I simply replace the unit... or the whole tank if still under warranty. However, sort of a answer... the unit either beeps once every 20 or 40 seconds or it doesn't beep at all... nothing in between.

2 - I'll await the drop test.

3 - Replacing the starboard tachometer... that tachometer will need to operate off of a 6 pulse engine charging system. It usually has a dial on the back of it which can be set to various numbers/pulse settings.

Before replacing it, I'd suggest checking the wiring at the powerhead as listed in my test procedure to see if the previous owner has already disconnected the tachometer gray wire from the regulator/rectifier gray wire at the terminal strip... and has the tachometer gray wire connected to the "yellow wire" of the stator.

And if so, that would give you a pretty good idea of the regulator/rectifier condition. However, whatever route you take to run the check is fine with me.

Where are you located? Tampa Bay Fl area here with another HOT day. Grass is about a foot high... time to crank the mower up. Busch on hand!

[268_Grady]

I went ahead and removed the plastic cover on top of the engine behind the flywheel to try to find the rectifier..........I got lucky and there it was!

3) Tested both rectifiers with my DVM. I've been in electronics for 30+ yrs so I wanted to test them instead of trying the Tach Test. To my surprise it looks as though both are damaged.
PORT Engine: w/ the neg DVM lead on the red wire of the rectifier I only got continuity on one of the high voltage yellow leads and with the positive lead on the purple wire I didn't get any continuity.
STB Engine: same results, but only got continuity on one high voltage wire with the neg lead on the red wire.
Measured the stator and read ~0.2ohms between high voltage wires.

Also wanted to mention the PO installed optimum batteries........not sure if that matters.
Also it looks like the stb side was replaced before.

Having trouble uploading jpg's!

[Joe Reeves]

I'll take your word on the DVM readings and I'm sure your electronic knowledge bypasses mine so I'll try to avoid corresponding in that area.

I never used a DVM in all my 30+ years at the bench. I understood the engines as I was with OMC back when the most complicated item was an electric starter. Magneto and mechanical shift was it, and 25hp (I think) was the highest hp until 1958 when the very first V4 (50hp) arrived on the scene. As the years past, all I had to learn was one or two new things... pretty easy when you start at the bottom. New technicians?.... It's impossible for them to grasp it all... the reasoning for NOT working on engines over 10 years old or so.

In 1973, the ignition system called Magneto Capacitance Discharge arrived and at one of OMC's seminars, I mentioned to one factory rep that this ignition system has to be the ultimate. That was 46 years ago and we're still using it... the components change in appearance somewhat but the system is the same. The DVM seems to be the easiest way to go for many but a 8.95 ohm/volt meter suits me fine... and I found that the engine components themselves could be used against/with each other to trouble shoot most ignition problems. Just opinions not worth arguing about... a case of what works for me and what works for them.

Optimum batteries?... A brand name or just a manner of saying the batteries are top notch? I know there are a few batteries that aren't supposed to be used but I've lost track. Being retired since 1991... I take Wal*Mart's word about what battery goes in my truck and car... and that's about it.

[268_Grady]

Updates:

1) Looked at wiring on port engine for oil tank sensor.....found both wires disconnected, corroded. Decided to run stb engine w/ wires disconnected and verified alarm did not sound. Going to leave wires disconnected and monitor oil level w/ gauges as they are functional.

2) Ordered (3) carb kits, Will advise outcome when kits are installed.

3) Water flow confirmed OK.

4) Have not had the chance to try tach test, That will be next. Plan is to connect a tach at the engine and perform the drop test. The tach on the port engine appears to be working so the tach test will not be effective here.....what else do you suggest?

[Joe Reeves]

Yes the tach test would not be effective if the tach is working... BUT... do check the wiring to see if the previous owner may have already switched that gray tachometer lead over to the yellow stator wire.

[268_Grady]

No changes were made by the PO