Mercruiser, needs full throttle to start when warm

[cookiesareyummy]

Mercruiser 1987 230 B520766. Carbed.

The engine will start fine when cold, when warm I need to put the throttle in full forward but I don't need to pump it. The choke is working fine and I don't see the barbed overflowing or anything. Let me know.

 

[Doernuth]

Re: Mercruiser, needs full throttle to start when warm

Check vacume if equipped, or may be time to rebuild the carb....

 

[cookiesareyummy]

Re: Mercruiser, needs full throttle to start when warm

Not sure what you mean by vacume, as far as the carb this one is new(rebuilt) but it was doing the same thing on the previous carb.

 

[dubs283]

Re: Mercruiser, needs full throttle to start when warm

if you need to have the throttle at wide open during cranking that mean the engine is flooded

did you rebuild the carb or was it a reman??

did you set idle mixture and idle speed??

have you verified there is no leaking of fuel down the throats upon shutdown??

 

[cr2k]

Re: Mercruiser, needs full throttle to start when warm

Check float setting.

 

[cookiesareyummy]

Re: Mercruiser, needs full throttle to start when warm

I made sure there was no fuel leaking from the carb into the intake manifold after the engine shuts down. I was looking for a cause of flooding but haven't found anything yet. No fuel is leaking down into the carb when the engine shuts down. It is a reman carb (all I did was take old one off and put this one on). I'll have to double check the idle mixture, I don't recall if I did it or not as it was some time ago. Engine does run smooth and great though other than this, even very nice at idle. I'll start with those idle mixture screws.

 

[wgl333]

Re: Mercruiser, needs full throttle to start when warm

I have a 95 Wellcraft with a 5.7 Mercruiser and I have the very same issue....starts great cold, need to almost full throttle to start when warm.....original carb....curious to hear your findings.

 

[Fordiesel69]

Re: Mercruiser, needs full throttle to start when warm

Quite common on all the 5.0L / 5.7L I have been around. Not quite sure why this occurs, but I can assure you, your not alone.

 

[cookiesareyummy]

Re: Mercruiser, needs full throttle to start when warm

Quite common on all the 5.0L / 5.7L I have been around. Not quite sure why this occurs, but I can assure you, your not alone.

Glad to hear it. What an odd thing. The engine is old so maybe they just get tired. I'm going to most likely look at it today or friday, I'll update if anything helps or not.

 

[rad1026]

Re: Mercruiser, needs full throttle to start when warm

Just had my carb rebuilt and it is doing the same thing. I am curious about what you find out. I will get down to my boat this week see what I can figure out also.

 

[SDSeville]

Re: Mercruiser, needs full throttle to start when warm

Wow! I am not alone. Mine does exactly the same thing. I don't complain about it since it runs perfect once running, but it is a litlle annoying. Anxious to see what causes this

 

[skargo]

Re: Mercruiser, needs full throttle to start when warm

Mine just started doing this after my engine swap. It would start fine first time, then later in the day it was flooded. I had to mess with the choke linkage while my wife turned the ignition and it started right up. My quadrajet is old so I had it rebuilt last week.

 

[CHEVYJEFF]

Re: Mercruiser, needs full throttle to start when warm

Ethanol makes gas boil in carb when hot and sitting after running
I have same issue w my 5.7
There is a mercruiser service bulletin on hot start
I wouldn't worry about it