'76 Johnson 75 Stinger fuel issue

[Keyboardman]

Hi all, The bottom carb isn't getting enough fuel to fill the float bowl. I've pulled the carb and checked that the needle valve isn't stuck or the inlet clogged. Fuel lines are all new and with no restrictions. A little fuel will drain out of the bowl after running, but not like the mid and top carbs. Possible weak fuel pump? The filter screen is clean. Thanks

 

[Chinewalker]

How do you know the carb isn't filling? Is the bottom plug running cleaner than the top two? Fuel running out of the bowl isn't an indicator of carb filling...

 

[Keyboardman]

Yes, that's what got me investigating. Inspecting the plugs, the top two are looking normal and the bottom was looking like new. Checked spark, 1/2" bright spark on all three. Drop cyl test showed no change when disconnecting the bottom cyl plug wire. Spraying fuel into the throttle body increases and smooths out the idle. Compression is 95 across the board.

 

[fireman57]

When you take that carb off look for something in the reed valves. Too many times a cover bolt gets loose and gets sucked back in there. Use a flashlight and you will be able to see in there. Just use a magnet to get it out.

 

[fireman57]

Also make sure your float is set correctly. Should be level when you turn the carb upside down.

 

[Faztbullet]

Check the bowl gasket as the fuel goes the bottom bowl ,thru gasket, into main body of card does a hard 45 the to needle. Have see the gaskets swell and choke off the passage way..

 

[boobie]

Is the high speed jet in the bottom of the float bowl clean ??

 

[fireman57]

Yes. It is behind the drain screw.

 

[fireman57]

Sorry boobie. Misread that as OP was asking where the jet was.

 

[boobie]

No problem..........

 

[Keyboardman]

Pulled the carb and nothing foreign was in the reed block. I'm just going to get a kit for it and rebuild. Might as well rebuild the fuel pump while I'm at it just to be sure on that. I understand that these carbs could use a larger low speed idle jet. Anyone know much about this? I haven't had it on the boat for a water trial yet and don't know if it may have this "Bogging down" issue I've heard about. Thanks.