4.3 Mercruiser hard starting

[Mr. Fry]

Hey guy. New to this site so bare with me please.
Anyways I just acquired an Invader Bowrider with a 4.3 6 cylinder Mercruiser in it. The guy I got it from says that he only ran it once last year, had it winterized and that's it. After multiple attempts the only way I could get it to start was to dump gas directly in the carb. It would burn what I put in and stall. I disconnected the fuel line and turned it over a few times and it blew out a pile of junk. I drained the tank and flushed it and put new premium gas in it. Then figured I better pull the carb out and clean it. Got all that done but still the same issue. Only way I can start it is to dump gas down the carb. Then once it's running it seems okay but will not idle unless I keep the rpm's up. In disconnecting the gas line to the carb and turning it over it shoots out gas very easily so I don't think anything is plugged in there. Any ideas on how to make it not hard to start??

 

[achris]

Hello and :welcome: to iboats...

What year is the engine (not the boat. Boat and engine can easily be different years).... Or failing the year, how about a serial number. And also, 2 bbl 4 bbl EFI or MPI?, Electric fuel pump or mechanical?

4.3s from about 1992 to the late 90s used a 4 bbl Weber (Carter AFB copy), and they are notorious for dribbling fuel after shutdown, making them hard to restart. If it's a Weber 9600 or 9666, then it is what it is...

Chris.....

 

[Mr. Fry]

Sorry for the late reply. I guess I should have included more details. I'm brand new to inboard motors so I'm not really up to par on all the terminology just yet. So I figured the best way is with pictures. Only problem is the serial number on the motor has weathered off. But I included pics of the engine, carb, and fuel pump
thanks

 

[Mr. Fry]

Sorry for the late reply. I guess I should have included more details. I'm brand new to inboard motors so I'm not really up to par on all the terminology just yet. So I figured the best way is with pictures. Only problem is the serial number on the motor has weathered off. But I included pics of the engine, carb, and fuel pump
thanks

 

[Mr. Fry]

[No message]

 

[alldodge]

The serial numbers are for 1983 to 1990 Alpha drive. The pic of the 4.3 tells us enough to get close, its a carb motor

Your fuel line coming from the tank needs replaced, its all cracked up. Need USCG approved type A1 fuelline, not from the local auto store.

Since you have to put gas down the carb to start, you probably have a clogged fuel pump or the fuel pump is bad. The fuel pump has a filter inside the pump

This is in the range for parts of your motor
http://www.mercruiserparts.com/4-3l-...-1988-1992-0b7

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Remove the bowl which is inverted on top the pump. Look at the filter and gasket
http://www.mercruiserparts.com/bam/subassembly/31478/951/90

You may have a Merc or Rochester carb, in any case there is a filter behind the large nut

 

[Rick Stephens]

Very probable that your carb also needs a rebuild. When you see dirty fuel system, you need to clean up everything.

 

[Bondo]

Then figured I better pull the carb out and clean it. Got all that done but still the same issue. Only way I can start it is to dump gas down the carb. Then once it's running it seems okay but will not idle unless I keep the rpm's up.

Ayuh,..... Welcome Aboard,..... Sounds like the carb needs a full blown Rebuild,....

The idle circuit is plugged up,.....