Clear flood mode

glens5

Cadet
Joined
Feb 6, 2013
Messages
6
I've rebuilt a number of automotive carburetors but this is my first marine unit. It is a Mercruiser carburetor from a 1998 3.0L inboard. There was no problem in rebuilding the carb until I went to adjust the choke plate opening clearance for the clear flood mode. I found the tab missing from the throttle lever that would normally force the choke plate to open at full throttle. The tab hasn't been removed from the throttle lever but rather, seems to have been manufactured without one.
Is this normal for marine carburetors to be made without this feature for safety reasons?
 

500dollar744ti

Senior Chief Petty Officer
Joined
Jul 23, 2012
Messages
691
Re: Clear flood mode

I'm not sure what is supposed to be there but I know mine doesn't have this "clear flood mode" you speak of, I wish it did.

For me "clear flood mode" involves going back to the engine with a screwdriver and propping the choke open.

Marine carburetors have a variety of safety items that are not used on automotive carbs, I wouldn't be surprised if it has something to do with that.
 

Don S

Honorary Moderator Emeritus
Joined
Aug 31, 2004
Messages
62,321
Re: Clear flood mode

Nothing fancy about marine carb adjustment. Where they differ is being vented so fuel can not be vented to the outside of the carb.

I think what you are calliing a clear flood mode is actually the choke unloader setting that opens the choke a little at full throttle ~1/8" or less instead of being fully closed at less throttle.
 

NHGuy

Captain
Joined
May 21, 2009
Messages
3,631
Re: Clear flood mode

The best thing you can do is to set it up to manufacturer's spec. A lot of development went into that design.
 

glens5

Cadet
Joined
Feb 6, 2013
Messages
6
Re: Clear flood mode

Thanks for the replies guys.
I will just assume then that this is normal for this carb. then and won't worry about it.
I'll maybe just keep a screw driver handy. :)
 
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