1998 Mercruiser 4.3L Thunderbolt V Fuel Sending Unit. not functioning
 

My 1998 Mariah is equipped with a 4.3L Mercruiser with the Thunderbolt V, appears to be equipped with the 2 bbl mercarb. The sending unit on the choke side of the carb appears to be malfunctioning and no fuel is going into the bowl of the carb. If I bypass the sending unit, the fuel pump comes right on pumps fuel. Does anyone know a repair or work around for this problem. As near as I can tell the sending unit and choke are not serviced seperately.
Thanks,
Mark

Re: 1998 Mercruiser 4.3L Thunderbolt V Fuel Sending Unit. not functioning
 

Here is a diag of the 2bbl Mercarb.

Mercarb 2 BBL

Can you give us a better idea of what "sending unit" you are refering to? :)
What is the serial # of your engine?

Don't mean to give you stress , but are you sure you don't have a EFI 4.3?

Re: 1998 Mercruiser 4.3L Thunderbolt V Fuel Sending Unit. not functioning
 

I found the problem it was corrision on the purple and tan fuel pump wire as it exits the oil preasure sensor above the oil filter. Works now! Thanks for the reply!

Re: 1998 Mercruiser 4.3L Thunderbolt V Fuel Sending Unit. not functioning
 

Glad you were able to pinpoint it Mark.
Pressure and temp switches combined with corrosion cause a fair share of grief around here:(