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Mercruiser Alpha Gen one

C

Chiefsfan1966

New member
I recently replaced my 5.7 mercruiser. Running the engine in the driveway with water hooked up, it shifts from forward to neutral to reverse and back again with little to no resistance. Took the boat to the lake and the shift cables become stiff and it's difficult to find neutral . It jumps from forward to reverse and has to be bumped and wiggled to get into nuetral. Help me understand what's going on? The switch that kills the motor is working fine also?
 
Sounds weird I recently inherited a boat with same 5.7 I have had similar problems but haven't gotten as far as you have I am still trying to get motor running after 7 years of storage.
 
Is there adjustment on the interrupter switch? Because that was the first thing I checked and I can manually get it to stall the engine? Maybe I need to be at the motor and have someone else shift it and see if the switch is ACTUALLY functioning under normal shifting?
 
What year is the boat?

What is the idle rpms in gear in the water?

The switch works as you say, The question becomes why is it not working when shifting out of gear?

The V notch piece of plastic on the shift bracket where the interupter switch is needs to move and activate the switch when shifting OUT of gear, forward or reverse. If the switch is not bieng activated then either the switch position can be slightly adjusted or the roller arm (depends on what design you have) can be slightly bent to allow activation sooner. Of course that assumes the cables are adjusted correctly. Has anyone adjusted the cables?
 
The mechanic I had install my new 5.7 had never installed an inboard mercruiser. He read about using a makeshift alignment tool to check engine/ gimbal alignment. But after he had it where he believed it to be best , the front of the engine was 3/4" LOWER than the engine that was removed? Could this mis alignment be the cause of my stiff cables and shifting difficulties?
 
Not typically,

I would recommend having it checked by someone with the correct alignment tool................if wrong you could blow out the coupler and the engine will have to be removed to replace it!!!!!

If he was unfamiliar with mercruiser then he may have routed the cable wrong, its hard to say.

Did he adjust the cables?
 
i dont think he adjusted the cables but instead just un bolted them and re installed them on the new engine. why would it shift smoothly in the driveway with no issue and while in the water become difficult?
 
It would be like having you vehicle on jack stands and shifting it into gear and accelerating vs having the vehicle on the pavement. Same thing with a boat, no load out of water and load in water.

Again, what are your idle rpms? Should be around 650 rpm in gear in the water under "water" load.
 
the other problem i have is the dipstick and tube. the remanufactured 5.7 block i purchased didnt have a dipstick/tube. a standard tube for a 1990 block wont clear the exhaust manifold water jacket. what tube and dipstick do i need? in searching i found a 15296A2 is this correct?
 
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