boatman747

2 dominators on 2 540,s . both are adjusted the same and have the same fuel pressure. The stb engines turn key and runs great . The port engine act likes it floods everytime I start it .And it loads up after a long idle . I dont see anything out of the ordinary in the carb . I alsmost have to hold the throttle wide open to make it start . Any suggestions from any of you motor heads , I d appreciate it . The 1050 dominators are brand new . And they run great when running . But I canalmost here the gas trickle on the plugs .

HighPriority

The first thing to check is the float level. The way to do that is take out the sight screw on the side of the carb. bowl. Gas should not come out of the sight hole unless you shake or bounce the boat. If the float is to high you can lower it by the adjustment on the top of the carb. bowl.

I hope this helps

boatman747

All float levels are correct .

Attack

If the power valve is blown, the dripping is common. You may also find that plugs # 1 and # 2 will be darker after idling. Replacing the power valve is easy and cheap. Just make sure you use the same vacuum level ie 3.5, 6, ...

boatman747

power valves have been replaced . Any more ideas ?

Liberator21

First thing I would do is swap carbs, and see if the problem goes with it.
Then take it from there. Make sure all the body screws are tight, and that they have all the correct, and undamaged gaskets. Just because they're new..........

Paul

KNOT-RIGHT

Excellent suggestion!

Airpacker

Make sure the secondaries are closing completely or they will pull some extra fuel into the engine from the rear jets.

Bulldog

New carbs-
All the more reason to check everything. I had a 750 Holley, new out of the box, on a Chevy 302 (Z28). The motor had no power, I checked fuel pressure, jets for obstruction, etc. The third time I pulled it apart, I saw #60 on the main jets. They were supposed to be #66's...

razor1115

Airpacker,

You will not pull fuel from the secondaries if you are on the idle circuit, and I don't believe the throttle plate stop for the secondaries will open them far enough to allow enough vacuum to pull fuel from the secondaries.



I have a 540 with a 4150 950HP. Adjust all four corners' idle mixture to obtain max vacuum UNDER LOAD! Tie boat to dock, idle around, whatever, just make sure it's under load. It may take three to four times adjusting. Start with one corner until you obtain max vacuum (use a gage on the rear vacuum port on the base plate under the float bowl) and engine starts to stumble. Back off until idle cleans up. Move to next corner, then next, etc. Now, recheck the first corner you adjusted to see if more vaccuum can be obtained. If so, keep adjusting corners as mentioned above. If not, you are there...

NOW, if the idle is low, seems like it's loading up (just like mine), DO NOT ADJUST the throttle stop to richen mixture. This will take the carb off the idle circuit. You will need to slightly open the secondary butterflies with their own stop until the idle starts to clean up. Keep at it until you obtain the idle RPM you are shooting for. Mine was 750 rpm under load, 1000 rpm out of gear. That's what I did, hope this helps - this is just to get the IDLE CIRCUIT set correctly.