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"95 Johnson 225HP Shift interrupter switch.

Salty Cells

New member
Greeting from South FL as a new member.
I seem to be having issue with what seems to me adjustment of the mounting hardware for the **** interrupter switch on my 225 HP Johnson. I know the switch is good since by manually pressing kills starboard bank therefore lowering RPM's to facilitate gears engaging. The issue is that when in place, the shifting linkage does not make enough contact to lower the switch plunger far enough to perform its function. Im curious to know if the switch mounting bracket has an adjustment. I wish I had a picture on hand to better illustrate my point. I will make an attempt to get one if need be.

Any suggestions or feedback from trade gear heads out there? Looking forward to any response and Happy New Year!!!!
 
I retired in 1991 and as of that date there was no adjustment. If one has been incorporated since then, I have no knowledge of it.

However, although the switch may indeed be actuated when shifting into gear... that is not the purpose of it. Its purpose is to momentarily kill the starboard bank so that it is possible to get the engine OUT of gear. I've encountered rigs where the engine had a faulty switch and even at idling speed, approaching a dock, the engine had to be shut down, neutral, quickly restarted, reverse... hair-raising even for an experience mechanic!

When fully operational, the kill cycle of that starboard bank is so short, it is quite difficult to notice.

Do you have a problem going out of either gear into neutral?
 
No adjustment.

If you try to operate the shifting mechanism, and watch it "work", that will not work either.

Tricky little design there.

It will only "Work" when there is a load on the propeller. As in underway.....

Or, you can simulate a load on the prop by putting engine into gear and using your hand, pull on the prop against the stopping force from the engine.
THEN, when you shift to neutral, you will see the interrupt switch lift much higher than if there was no load to the prop.

Do it both for forward and reverse, and you will probably need a helper to do the shifting while you watch and hold load on the prop.
 
Thank you for the quick response. The only issue I see if a bit of gear grinding when taking in/out of gear. I'm doubtful of the switch being engaged because when I slowly switch from Neutral to reverse/forward, I dont hear RPM decreasing. Even if I try to hold the shifter at the point where switch should be activated (or deactivated depending if its a normally open switch).
 
Interesting comment on prop being under load. I never thought of that, wouldn't think it would matter. I am honestly working on it while on the trailer so I guess I could launch and see if that makes a difference.
 
You are not getting it. The switch only actuates when going from forward OR reverse to neutral.

If you want to test the switch itself, start motor and using an appropriate tool, reach in there and press the switch plunger. Engine rpms will drop.
If not, switch is bad, or the wiring from the switch to under the powerpack is incorrect.

Grinding when shifting? You MUST NOT LINGER through the shift. Make the shift with a quick positive movement, not slowly.
 
The switch works fine because when manually pressed, rpm's lower. I just don't see shifter linkage reaching the switch plunger far enough to cause those those RPM's to drop either from Forward/Reverse gear to Neutral or vise versa
 
As I said, it is a tricky mechanical design. There has to be a load on the prop, and you must be going from F or R to N. Not the other way.

Do like I said and load the prop by pulling on it while in gear, and then shift. If all is correct, that switch will actuate.

Also, as I said, there is no adjustment.
 
Gears grinding... coming "out" of gear? Either the shift cable's out of adjustment (not centered) or the lower unit shift rod has been turned out of it's proper measurement.

If you can shift out of gear normally without applying brute force to the shift lever... the cutout switch is working normally. It acts so quickly that it cannot be noticed. Don't overthink it.

A small portion out of my database pertaining to gear clicking........
Some boaters with manual shift engines have the mistaken belief that shifting slowly is taking it easy on all of the shifting components..... Wrong! Shifting slowly allows those precisely machined sharp edges of the dog and gears to click, clank, bang, slam against each other many times before they are finally forced into alignment with each other..... and this is what rounds those edges off! The proper way to shift is to snap the unit into gear as quickly as possible.
 
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