318 4 BBl carb

[hammerhead]

Have a 1979 f30 with twin 318s in it. The port engine the four-barrel is not opening up. What could be the cause of this. Not sure on what make the carb is but I will attached a couple pictures of it.

[hammerhead]

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[hammerhead]

clarification. the secondary isnt opening

[prowlersfish]

Make sure the cable is pulling it fully open . Will it fully open with the cable off ? BTW there should be no rubber hose or plastic fuel filter going to the carb .

[mikeandanne]

Just to add, your choke plate is fully open, but there is a small hanging tab on the linkage at the side which will not allow the four barrels to open when cold. Sometimes the tab is worn and sticks, have a look and watch the linkage as you work the throttle from closed to full open with the engine off of course. Looks like an AFB.

[hammerhead]

Make sure the cable is pulling it fully open . Will it fully open with the cable off ? BTW there should be no rubber hose or plastic fuel filter going to the carb .

yep new cable on both engines. they fully open. i know about the fuel lines just have a lot of little *** to fix. it was running fine a couple weeks ago but yesterday we went out and the port engine throttle was only responsive up to about 3/4 open then nothing. long 10 mile trip at 11 mph

[hammerhead]

problem solved. someone before me put the wrong base gasket and the holes were smaller on the secondary ports. they were small enough that the flappers could not get past the gasket to open

[P-Dogg]

BTW there should be no rubber hose or plastic fuel filter going to the carb .

Not to mention a spring-type clamp on a pressurized (gasoline!) hose!

[hammerhead]

yes all the fuel lines were replaced.
Put the right gasket on the carb so the 4 bbl opens now but still only getting 1800 prms running the boat. when you rev it up in neutral it pops up to 2400 just fine but under power only get 1800. transmission??????

[prowlersfish]

yes all the fuel lines were replaced.
Put the right gasket on the carb so the 4 bbl opens now but still only getting 1800 prms running the boat. when you rev it up in neutral it pops up to 2400 just fine but under power only get 1800. transmission??????

Is 2400 the best you got in neutral ? is this issue with both engines ? what speed are you getting at 1800 ?

[hammerhead]

this is only the port engine. only getting 11-12 mph with both engines at 1800 rpm's. the starboard has a lot more throttle left but you cant run it wide open because the boat will turn to hard right to control.

[prowlersfish]

Is 2400 the best you get out of gear ?

[hammerhead]

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This is a picture i took the other day. this is the position of the throttles synced at 1800 rpm's. if you advance the port engine forward there is no more response from the engine. if i advance the starboard throttle the boat goes hard right overriding the steering. we checked all linkage and it is working fine and throttle is fully open on carb. SB maxes out at 2100 rpm's.

[hammerhead]

Is 2400 the best you get out of gear ?

thats as far as i pushed it. didnt want to hurt the motor reviving it up without a load on it

[prowlersfish]

Ok so your getting 1800 on the port and 2100 out off the starboard . So while the port will hold back the starboard some , it would not be that much . Its time to look at the boat . It sounds like classic dirty running gear and or bottom . I would haul her out and check . Mine sat for a few weeks a month ago and I then from a 20 knot cruise to not getting on plane and 1000 rpm loss . ( a lot on a diesel )

The problem ? Dirty shafts a little growth on the props ruddes but the shaft where most of it . Seen the same happen on my F30