How long should 4.3l turn over?

[20002760]

On a cold start my 4.3's turn over for about 8-10 seconds before firing up. After that they start immediately. I just want to make sure this is normal

 

[Don S]

Re: How long should 4.3l turn over?

2-3 seconds max. But you have to be using the proper starting procedures and everything needs to work.
Do you have a carbed engine or EFI?

PS: The words 4.3L don't tell us much, they have changed many ways over the year. Year is only close info, model and SN are what is needed on boats engines.

 

[20002760]

Re: How long should 4.3l turn over?

Port 0L606199
Starboard 0L606161

 

[Don S]

Re: How long should 4.3l turn over?

Carbed with 2bbl carb.

Do you use the throttle only position to give it throttle when starting, or leave it at idle position?

 

[NetDoc]

Re: How long should 4.3l turn over?

On a cold start my 4.3's turn over for about 8-10 seconds before firing up. After that they start immediately. I just want to make sure this is normal

Sounds like a carb with the choke disabled. If so, try pumping the carb twice before you start it.

 

[20002760]

Re: How long should 4.3l turn over?

I typically give it a little throttle. I will try pumping it twice and see if it helps.

 

[mpdive]

Re: How long should 4.3l turn over?

Is it a TKS (turn key start) carb? There is a pre set starting procedure for TKS's NO CHOKE on a TKS

 

[joewithaboat]

Re: How long should 4.3l turn over?

I have only had my 1996, 4.3 v6 merc, 4bl for this season and have been busy fixing tons of little things........... but mine has always taken two 10 second cranking cycles before it starts. I suspect that the fuel pump power and or the run ignition power are on a safety switch that wont provide voltage until oil pressure comes up. There are many here that will know for sure. Mine will try to start if you pump it 2 x before first cranking but wont stay running. All this is a 6-8 day cold start. We go every sat or sun afternoon. When warm it starts right up. I think because the bowls are full and oil pump is primed at this point.

If this turns out to be the case its actually a good thing. We used to wire in a momentary switch on race car motors to hold down while cranking until the oil pressure moves and then let loose. Saves wear on the motor.

Happy Boating, Joe

 

[Bondo]

Re: How long should 4.3l turn over?

I typically give it a little throttle. I will try pumping it twice and see if it helps.

Ayuh,... Most carbed motors need at least 1 stroke of the throttle to Wot, to set the choke closed for a cold start....

My ole 4.3l gets a couple of full throttle pumps, 'n then 1/2- 3/4 throttle til she lights...
Then pull back to just above idle...

 

[Pierutrus]

Re: How long should 4.3l turn over?

Ayuh,... Most carbed motors need at least 1 stroke of the throttle to Wot, to set the choke closed for a cold start....

My ole 4.3l gets a couple of full throttle pumps, 'n then 1/2- 3/4 throttle til she lights...
Then pull back to just above idle...

What Bondo said......Mines the exact same way.
I've learned that when you apply water to the outdrive, like on the muffs/with hose attached.....It starts right up. Because you have water pressure going up the outdrive.

On the other hand, when you just dunk the boat in water.....You have back pressure and the engine takes a little bit more for it to fire.

Just my experience.

 

[mpdive]

Re: How long should 4.3l turn over?

Is it a TKS carb? I think I asked this already...

 

[joewithaboat]

Re: How long should 4.3l turn over?

So does anyone know if the fuel pump power is tied to the oil pressure switch. Ive had tons of carbed motors over the years and never had to crank them over that long to run. i think ill put a test light on it next time out.

 

[Bondo]

Re: How long should 4.3l turn over?

So does anyone know if the fuel pump power is tied to the oil pressure switch. Ive had tons of carbed motors over the years and never had to crank them over that long to run. i think ill put a test light on it next time out.

Ayuh,... If you've got an electric fuel pump, it's powered through the O/P switch when runnin'...
It's also powered from the tiny outside stud on the starter, when crankin'...

 

[joewithaboat]

Re: How long should 4.3l turn over?

Thanks for the conformation Bondo, i figure someone like yourself would know. This sight sure has tons of help from folks like yourself. I have a related topic but i will try to start my own thread instead of highjacking.

 

[egldvrbags]

Re: How long should 4.3l turn over?

On a cold start my 4.3's turn over for about 8-10 seconds before firing up. After that they start immediately. I just want to make sure this is normal

Similar issue but I have a Weber 4bbl on my 1995 4.3lx. I've found that after my boat has been sitting for a week or so, I have to crank it for about 10 secs or so to allow the electric fuel pump to run and fill the carb bowl. Then, I turn the key to the off position, then do the "carb" starting procedure, and she will fire right up.

As others have stated, the electric fuel pump only operates during cranking or when the engine is running w/ oil pressure. This is why I have to crank mine first for about 10secs to get fuel to the bowl.

Here's a thread w/ the info about the bowl drying out on the Weber. Don't know if your carb is similar:

http://forums.iboats.com/showthread.php?t=278075

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