Mercruiser 4.3 gear selecting

I

ian ash

Cadet
Joined
Mar 6, 2010
Messages
28
Hi there I have a 1990 mercruiser 4.3 v6 with a alpha one gen 2 stern drive.

Is it normal to make a crunching noise when selecting forward and reverse gear??? Its doesent last long just a sharp crunch then its in gear.

Cheers Guys
 
Don S

Don S

Honorary Moderator Emeritus
Joined
Aug 31, 2004
Messages
62,321
Re: Mercruiser 4.3 gear selecting

Yes, they have a dog style clutch inside the lower unit. You are supposed to shift briskly, usually 1 may 2 ratchets at the most before you get it in gear. Also make sure your engine idle rpm is around 650 to 700 rpm in gear while moving (not tied to the dock).
 
I

ian ash

Cadet
Joined
Mar 6, 2010
Messages
28
Re: Mercruiser 4.3 gear selecting

Cheers Don!
How do know if the shift interupter switch is working properly.Im sure iv read i should hear the engine revs dropwhen shifting. Thinking back to yesterday im not sure the engine revs are dropping.Should it be noticible to the ear
cheers ian
 
JustJason

JustJason

Vice Admiral
Joined
Aug 27, 2007
Messages
5,319
Re: Mercruiser 4.3 gear selecting

The interupt switch activates only when coming out of gear. It does not activate going into gear.
 
Don S

Don S

Honorary Moderator Emeritus
Joined
Aug 31, 2004
Messages
62,321
Re: Mercruiser 4.3 gear selecting

Click Here and go to item #4. It will explain in detail how the shift interrupt system works, and why.
 
180shabah

180shabah

Rear Admiral
Joined
Mar 26, 2005
Messages
4,995
Re: Mercruiser 4.3 gear selecting

Interrupter just causes the engine to "stumble" when shifting out of gear. If it stalls when shifting, then the lower cable probably needs replaced.
 
You must log in or register to reply here.
Top