Starting issues after sitting all week

gdavis67

Active Member
Mar 1, 2017
137
Saugatuck, MI
Boat Info
1990 390ec
Engines
Twin 454 Mercruiser T 340 with Hurth drives
This is regarding my 1990 390 EC, but I have had similar problems with previous boats so it's not unique to my current boat. After the boat sits for the week without us there, the first startup of the weekend is always difficult. 20-30 seconds of cranking each motor, let starter cool, then crank again with the throttle advanced a little to help fire. Generally starts on the second attempt. Both motors and the gennie are this way. Gennie takes three attempts. It's like the fuel is being siphoned out of the carb and back into the tank. I have checked all of the air vents for the fuel tanks and they are clear and clean. Any other ideas? Not really a big problem, just an annoyance.
 
Carburetor bowl dries out after sitting, fuel evaporates out - my 4.3 is the same way. This is what I do.

Crank engine 5-10sec - this fills the fuel bowl.
Pump throttle 2-3 times - this squirts fuel into the intake and sets the choke
Open throttle 1/3 and crank

Mine fires up everytime this way.

If it has only sat a day or so, one pump and it fires right up.
 
Mechanical or electric chokes on your carbs?
If mechanical, push throttle all the way forward once to set the choke, pull it back, and then crank the motor.
 
After a week or so my 270 will only start by giving the throttle 3 slow full pumps, and cranking continually while slowly pumping the throttle. My Monaco will not start that way at all, but rather fast full throttle pumps. You may have to try a few different ways to find the right one. So happy the new boat is fuel injected...

MM
 
BillK2632 - Exactly the same process I use and it works 100% of the time. I was more curious if anyone else that had this issue had found a resolution or if it is just the way things are. Thanks all for your replies.
 
BillK2632 - Exactly the same process I use and it works 100% of the time. I was more curious if anyone else that had this issue had found a resolution or if it is just the way things are. Thanks all for your replies.

It's just the nature of the beast with a carburetor engine.
 
BillK2632 - Exactly the same process I use and it works 100% of the time. I was more curious if anyone else that had this issue had found a resolution or if it is just the way things are. Thanks all for your replies.

Truly just the way things are...

MM
 
Same for mine....
Crank engine 5-10sec - this fills the fuel bowl.
Pump throttle 2-3 times - this squirts fuel into the intake and sets the choke
Open throttle 1/3 and crank
 
Been playing with carb motors for about 50 years. Had carbs on the motors on my old boat.
My 68 GTO has a carb with mechanical choke linkage, as does the 2005 18’ Maxum we have for my kids to use.
Both have mechanical fuel pumps and both start evertime using the following method.
If your carb is okay, you should be able to just punch the throttle all the way forward then back once to set the choke, then crank with throttle advanced just a little bit and the motor should start.
Took me a while to train both kids to do it that way. Also have two neighbors with classic cars that frequently have trouble starting them and wind up flooding their carbs. Like my kids, they grew up on fuel injected cars.
When they knock on my door to help them get their cars started I have to go through the drill with them again. They usually have the problem when they forget to depress accelerator once to the floor and release to set the choke. When it won’t start, they start pumping the pedal and flood the carb.
Again, this is if you carb is in good shape.
 
NOT MINE - 1989 Sea Ray 210 Bowrunner - GMC 4.3 Liter V-6 2-bble Carb -- let sit for a week, this puppy will not start, jacking the throttle or anything. Clearly, fuel had been sucked back down into the tank and starter rpm is too slow, voltage output too weak and safety override on throttle protecting engine from low oil presure kicks in and won't let the start signal reach the pump. So ...

I pull the engine cover and the spark arrestor from the carb and pour in 1/4 cup gasoline. Button her up, hit the start switch and she fires right up -- first time. Gets enough spin to fill the carb and off we go. After that, in the next week, if i start her up, takes only a single throttle stroke to set the choke and cranks up no problem.

By the way, hitting the throttle once turns on the choke. Hitting it more times will turn it off -- not helpful when the engine is cold.
 

Forum statistics

Threads
112,944
Messages
1,422,720
Members
60,927
Latest member
Jaguar65
Back
Top