Couple of questions regarding my 4.6L Mercruiser

thunked

Cadet
Joined
Sep 4, 2009
Messages
17
Hello,

I have a 1991 Bayliner with a 4.6L(maybe 4.3) I/O. This boat has been great to me, I bought it 4 years ago and besides basic maintenance I haven't had issues until now.

Wondering if anyone can give me some input on possibly how to diagnose these issues or what they may be -

1. After sitting for a while my boat would not start. I would turn it over and over and wouldn't start - finally I discovered a small switch near the throttle cable, which whenever I engaged the throttle this throttle switch would remain depressed by the throttle mechanism - almost like the throttle mechanism was trying to keep it depressed. I understand this is a switch which reduces idle for going into gear? Well I had to remove the switch in order to get the boat started. When I run the boat on land, it starts right up sounds great, runs great - HOWEVER, when I put the boat in the water - it will start(have to turn it over a bunch of times once it hits the water) but I cannot give it any gas with the propeller engaged(I was able to on land), it's like it wants to die out right away. I was able to give it a little gas and it accelerated for a few feet then died. Do I need this switch on?

2. This issue of the boat not running in the water - could this possibly be that my exhaust flaps have worn away, and when backing into the water- the water is getting into exhaust? Because once I put the boat in the water, it just would not start for about 10 minutes - while I started it about 15x over the previous 2 days on land to make sure it was going to run.

3. As I said, I've only changed oil and oil filter over the 4 years I've had it- what types of things should I look to replace or maintain that may help or point to the problem and why I'm experiencing these issues?


Thank you so very much for any responses.
 

proxyx

Banned
Joined
Aug 28, 2009
Messages
135
Re: Couple of questions regarding my 4.6L Mercruiser

1. no, switch seems working, you need shift cable adjusted - serviced
2. with or without exhaust flaps it should start at least, strange
3. too many things too list, you need to check the manual for the boat

in general, fuel system maint.(filters etc.), spark plugs etc (ignition), outdrive inspected, oil changed (outdrive) cabling adjusted.
 

jtybt

Senior Chief Petty Officer
Joined
Aug 5, 2009
Messages
730
Re: Couple of questions regarding my 4.6L Mercruiser

After 4 years, it's about time you did a complete tune-up.
 
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