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Alpha one leg wont come out of gear

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david_1980

Member
just purchased a used boat whi

just purchased a used boat which has a 3ltr mercruiser engine and an alpha one leg took it for a drive this weekend and found it would go into gear drive perfect but would not come out of gear unless you turn off the engine this makes parking a nightmare. the boat has been idle for a year and a half does any one have any suggestions this is my first inboard with an outboard leg only ever had outboards before thanks in advance
 
and if it`s operating correctl

and if it`s operating correctly you need a new shift cable or some corrosion cleaned up
 
"i had a look at the switch wh

"i had a look at the switch which is located on top of the rocker cover the previous owner has it positioned in such a way that it does not get operated by the cam ( when you move into gear the switch does not close) would this cause my problem also this problem does not occur out of the water, it all moves fine with engine off or with the engine on and muffs on.i also tested the sw for continuity and it was fine so dont know why he moved it.when on the water if you turn off igniton it will go out of gear no problem. thanks for your swift replies"
 
"Way too high, I think 650 - 8

"Way too high, I think 650 - 850 would be closer to the mark. I Have my 350 V8 at 750rpm, 650 in gear in the water, not sure what the 3L should be but maybe some of the guys on here will know."
 
"the arm that closes the switc

"the arm that closes the switch shouldn't move much unless the drive is in the water and 0unning(if it doesn't move easily then it should be disasembled and cleaned) dont bend the little spring arms, the PO previous owner may have bent the lever to not engage it as it might have caused the engine to die for other reasons (may be he was shifting to slowly) your idle should be about 600-700 in water in gear and about 800 +-50 in neutral in and out of the water. Let the engine warmed up before setting the idle and idle mixture, you can press on the switch lever for about 2-5 seconds while the engine is running to check its operation."
 
"ok just had annother look wit

"ok just had annother look with your answers in mind found the engine running at 1000 rpms on idle after warm up, put it into gear and back out and it runs at 1500 for long period adjusted and cleaned the throttle cable and have it set to 800 ish, the arm of the switch is bent back so not to engage, while the engine was running and in neutral i pressed it and it died straingh away i also bent the switch leaver back to where it should be and as soon as i put it into gear it died also, where do i go from here i am still not sure what this switch brings on, maby some one could enlighten me this might help me understand its use thanks again"
 
"First, set the switch so it a

"First, set the switch so it allows the engine to run all the time, in and out of gear. Then see if it will come out of gear at 800rpm in the water. Then go back to the switch if needed. The engine should return to idle quickly, should not hang up at 1500 rpm. Maybe the throttle cable is a bit sticky."
 
"David if the switch is engage

"David if the switch is engaged for too long it will kill the engine, it's supposed to only engage for maybe .5-1 second, not the 2-5 I mentioned earlier, should be very brief.

The Shift Interupt system works ONLY when there is strain on the shift mechanism from the engine running and in gear in the water. The Lever should NOT move or not move enought to engage the switch when the boat is running out of the water. If it does than the lower shift cable maybe binding and needs to be replaced, but clean the bushing in the interupt lever first a scotch brite pad works great, or very fine sand paper or fine steel wool.

When you try to shift ONLY from forward to neutral OR reverse to neutral the ARM should move quickly and return quickly to very very briefly engage the switch, thereby interupting the ignition system which then momentarily takes pressure off the gears and outdrive shift mechanics enough to allow it to disengage.

There is a metal bushings inside the lever and it can get dirty and it will cause it to work slowly and not return quick enough, killing the engine.

This happened on my own boat."
 
guys thanks very much for your

guys thanks very much for your help will report back after the weekend! one last question would anyone know the degrees before tdc for timing purposes might aswell give a good going over as im at it 3ltr lx serial no.k160214
 
"Per SELOC Manual

3.0L with

"Per SELOC Manual

3.0L with Alpha or MR OD uses MR43T Plug, Gap is 0.035, Timing: 6 deg. BTDC

3.0LX w/Alpha OD uses MR43LTS Plug, Gap is 0.035, Timing: 8 deg. BTDC"
 
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