Mercury Cruiser I/O 4.3LX Alpha One 1992

Joined
Sep 23, 2008
Messages
4
I purchased a Larson 19' Cuddy with the above I/O engine. I had fun with the
boat all summer no problems except that I find the motor hard on starting.
Manual says to pump 3 Times then turn on ignition. After a couple of times doing this I gave up and presently have to pump about 8 times and then advance throttle forward before I turn on the ignition. Engine still will not start right away and it takes me from three to four attempts before it starts. Once it starts I have no problem except if I have been fishing in one spot for over an hour. Then again I have to pump it one or twice before it starts.
Boat is normally tied to a dock all week and only used during the weekend. I use regular unleaded gas. I asked a few people and they all tell me that because it is carburated I have to pump the gas. I still think I should not be pumping that much.
I wonder if anyone has the same problem and how they solved it.
 

JustJason

Vice Admiral
Joined
Aug 27, 2007
Messages
5,319
Re: Mercury Cruiser I/O 4.3LX Alpha One 1992

it should be 2 pumps of the throttle then hold it open 1/4 to 1/3....

you may be flooding yourself out and that's why your having problems...

or...

you may have fuel system issues. up to and including a dirty carb.

with the engine off.
pull off your flame arrestor, hold the choke open by hand, have somebody put the throttle in nuetral and pump it all the way foward once.

Do you see 2 steady streams of fuel spray out down the throat of the carb?
 

180shabah

Rear Admiral
Joined
Mar 26, 2005
Messages
4,995
Re: Mercury Cruiser I/O 4.3LX Alpha One 1992

I assume we are talking about cold starts here. This is carbed so it does require active participation in the starting procedure.

You may have an empty fuel bowl after sitting all week. Try this:

Crank for 4-5 seconds THEN,
pump handle twice,
Open throttle about 1/4,
hit the key and be ready to adjust the throttle to keep RPMs under 2k.

You may need to fine tune the above procedure, number of pumps, throttle setttings etc, might even take two or three attempts before you have gas in the carb.
 

Chris1956

Supreme Mariner
Joined
Mar 25, 2004
Messages
27,036
Re: Mercury Cruiser I/O 4.3LX Alpha One 1992

Rich, I had much the same experience as you. Suddenly the carb bowl seemed to go dry in a week, which it had never done before. I would pump the throttle while cranking when cold, until it would start. It never took more than 5-8 sec.

BTW - I never had to do anything special to restart it anytime after the initial start. just turn the key, and off it went.

You might check the choke to see that it works correctly.
 
Joined
Sep 23, 2008
Messages
4
Re: Mercury Cruiser I/O 4.3LX Alpha One 1992

Hi Captain Jason,
thank you for your advise. Boat has presently been winterized. I will follow
your instructions when I start again next summer.
Regards
Richard
 
Joined
Sep 23, 2008
Messages
4
Re: Mercury Cruiser I/O 4.3LX Alpha One 1992

Lt.Com. Shabah,
Thank you for your advise. I have printed your instructions.
Boat has presently been winterized, but I will try as you explained next summer.
Thanks again.
Richard
 
Joined
Sep 23, 2008
Messages
4
Re: Mercury Cruiser I/O 4.3LX Alpha One 1992

Hi Chris,
Thank you for your advise. I understand exactly what you are saying and you are right. After it starts, I have no further problems. Needless to say If I stop to fish in one spot for over 2 hrs I find that I have to pump once before I start. Realistically there is no problem after the initial first cold start.
I did receive another two more suggestions for the Cold Starting procedure.
One told me to only pump twice then move the throttle forward about a third of the way and then crank. He thinks I am flodding the carb and that could be the problem. The other suggested to crank about 5 seconds first then pump two to three times and also advance the throttle forward. I will see if any of these procedures will work when I put the boat in the water next summer.
Meantime thanks for your reply.
Regards
Richard
 
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