Here we go again

[kb3gup]

Well after thinking about it I decided to replace the gears on my motor (1992 Johnson 60hp VJ60TLENE). Thanks for every ones help. Now onto a couple of questions. I took my hydrofoil off to see if I could gain a couple of extra MPH at top end. (also fits better in the garage ). When I did this the RPM's went up to about 6000 WOT, the specs call for 5500, I'm not sure I trust the tach though, because it will peg out over 7000 while it's revving up and sometimes just jump up to that and stay there with no change in the sound of the motor. I replaced the tach last year and set it for 6P, but I think the sender unit might be bad? If so I might as well have that replaced with the gears, what would the approximate cost be for that? My other question is does my motor have a rev limiter on it that will protect me from my own stupidity? Thanks again.

 

[tashasdaddy]

Re: Here we go again

not really following your question. 5500-6000 is where you want to be. what gears are you wanting to change. if lower unit, and trying to pick up speed. do it with a prop.

 

[ottertail]

Re: Here we go again

The tach gets its signal from the charging system, (Grye lead) changing the gears will not affect that signal. If you suspect the tach is getting poor signals then you will need to trouble shoot the charging system for the fault. Make sure all of your wire connections are clean and tight at the tach.

 

[dimock44]

Re: Here we go again

Do you have the small 3 wire rectifier? If so test the rectifier as it can cause the type of symptoms you describe for your tach.

Small Rectifier Test, by Joe Reeves
Perhaps your engine does not have the water cooled regulator/rectifer but rather incorporates the smaller 3 wire rectifier which sits just forward of a vertical electrical strip on the starboard side of the engine.

If so, a failed rectifier would knock out the tachometer. See the following.



Remove the rectifier wires from the terminal block. Using a ohm meter, connect the black lead of the ohm meter to the rectifier base (ground), then one by one, connect the red lead of the ohm meter to the yellow, yellow/gray, then the red wire (some rectifiers may also have a fourth yellow/blue wire. If so connect to that also). Now, reverse the ohm meter leads and check those same wires again. You should get a reading in one direction, and none at all in the other direction.

Now, connect the black lead of the ohm meter to the red wire. One by one, connect the red lead of the ohm meter to the yellow, yellow/gray, and if present, the yellow/blue wire. Then reverse the leads, checking the wires again. Once more, you should get a reading in one direction and none in the other.

Note that the reading obtained from the red rectifier wire will be lower then what is obtained from the other wires.

Any deviation from the "Reading", "No Reading" as above indicates a faulty rectifier. Note that a rectifier will not tolerate reverse polarity. Simply touching the battery with the cables in the reverse order or hooking up a battery charger backwards will blow the diodes in the rectifier assy immediately.

 

[5150abf]

Re: Here we go again

A boat lower isn't like the rear end in a car, there is only one set of gears, as stated you change your "gearing" with the prop by increasing or decreasing your pitch and diameter.

A boat motor is made to run an rpm, regarless of speed, you want to prop to get that rpm at WOT, running more or less RPM than recommended will only hurt the engine, sounds lie you are right in the neighborhood now.

The only reason you change gears in an outboard is if they are damaged.