4.3l merc trouble starting

I've got a 1995, 4.3l merc. It sits in the marina slip idle Sunday night through Thursday. On Friday nights she giving me a real tough time starting. Once she gets started, I can turn it off and she restarts with the flip of the key. Saturday and Sunday the 1st start is a little trouble problem. 75% of the time I can get her running. But again once shes running she'll restart without a problem.

If I give it 2 shots of CRC in each carb intake she always starts right up any day of the week.

I've got 2 batteries in the boat. I never do a 1st start on the one with the bilge pump. She cranks strong and fast so the battery isn't a problem. Once shes started she runs smooth. So I don't think it's a tune up problem. Any takers?


Tom

Re: 4.3l merc trouble starting

What is your exact starting procedure after it has been sitting ? Do you pump the throttle before cranking?

Re: 4.3l merc trouble starting

choke/accelerator pump, fuel pump problem? carbs need cleaning or rebuild?

Re: 4.3l merc trouble starting

Starting procedure:

1.Open the engine cover and check the oil & outdrive fluid.
2.With the engine cover open, run blowers on port battery (same one that has builge pumps) while stowing stuff (3-5 min).
3.Pump throtle to WOT 2x
4.Stop at 1/4-1/2 throttle and crank
5.Do not crank for more that 3 Mississippis
6.If she doesn't start after 3 attempts (step 5), I repeat step 4, then 5.
7.When I do get her started, I let the boat warm up with the engine cover open for at least 5 min before pulling out.

I'll do 3 reps of steps 3,4,5, and 6 before giving a shot of CRC. Then it starts on the first crank. I drained my tank last year for the hell of it. I figured it's never been done. So it sounded like a good idea.

Tom

Re: 4.3l merc trouble starting

I forgot - I switch batteries to the starting only (1 year old) battery before trying to start the boat.

Tom

Re: 4.3l merc trouble starting

Our '05 Bayliner has a 4.3L Merc as well. I don't know if this will help but I push the throttle all the way down twice, then leave the throttle at 1/2 way down and try and start it. But I've noticed that the longer the boat sits, I need to push it all the way down 3x or 4x and then leave it about 1/2 way down and turn the key. This always works for us w/out any additional "stuff". But when I get it winterized in a month or so I plan on asking the shop to take a look at it. I've heard you should only need to push the throttle down all the way just once or twice and then it should start.

Re: 4.3l merc trouble starting

I've got a 1995, 4.3l merc.If I give it 2 shots of CRC in each carb intake she always starts right up any day of the week.

Click to expand...

Ayuh,... What carb is it,..??

Have you looked to see of there's Gas at the carb when it Don't start,..??

Re: 4.3l merc trouble starting

Try 7 or 8 mississippi's, maybe up to 10. Ten seconds is ok for a starter if you wait 3 or 4 seconds between attempts. On your engine I believe it is an electric fuel pump and will only get power during cranking or while the engine is running. If the carb is draining down some then the fuel pump may need 7 to 10 seconds to begin to draw fuel and get it up to the carb.

There is something that needs attention, but cranking a little longer may get you past needing the crc.

Re: 4.3l merc trouble starting

Well it looks like the Mississippi's did the trick. I took my time this weekend and for a boat that sat 2 weeks in the water, she started on the 3rd attempt.

Thanks all,

Tom