5.7 litre 350 carb issues

[v-twindad]

Hello all,

I have a 1991 Sanger with a 5.7 litre 350 that has a holley marine 4 barrell on it, the whole engine/carb only has about 25 hours total. My problem is that the boat runs great when running, no problems, but when I stop to load/unload skier or let the kids swim for a while it takes forever to start back up (like its flooded or something). This is an inboard direct drive boat so the engine sits at an angle (nose up). I have read about adjusting the floats on Holley 4 barrell carbs and it all says to adjust fuel level to bottom of sight holes, but Im assuming that this adjustment will only work on an engine that is in a near level condition and I dont see any other adjustments on the carb. Is there a trick to adjusting the floats on an engine that sits at a pretty good angle? I have also checked the electric choke for operation and it seems to be working normaly, probably need to adjust that to, any tips or help with this matter will be greatly appreciatied.

Thanks
Chuck

 

[JustJason]

Re: 5.7 litre 350 carb issues

take it out for a run and get it good an hot. then kill the motor, pull off the flame arrestor and look down the barrells to see if fuel is dripping.

the other thing, and your not going to like this because most watersport people hate to hear it. When your towing and working the engine really hard, you need to pull the throttle back into nuetral and let the engine idle for a minute or 2 to help get rid of the heat soak.

 

[wca_tim]

Re: 5.7 litre 350 carb issues

if it is overheating the carb and pushing fuel out, an insulating carb gasket or even phenolic resin spacer can help a lot as can making sure you're getting cool air into the engine compartment, etc... the insulating gasket especially. If you've got a cast manifold it will hold a ton of heat, aluminum is a great heat sink (your carb) and the heat transfer is pretty efficient through many types of gaskets... all just adds to it. They also make heat shields but I've never tried one

 

[KJSmitty]

Re: 5.7 litre 350 carb issues

You are correct, the float level should be set so fuel is just setting on the bottom threads of the fuel level hole etc.. Same for front and back (primary and secondary floats - angle of engine should not effect this).
This should be "very carefully" checked while engine is running at normal operating temp.... And I said "checked" while running. Not "adjusted" while running.
If you loosen the needle/seat screw while running you will get quite the spray of fuel. Once you determine if the level is high/low, shut the engine off and adjust the need/seat up or down equivalent to the amount high or low that the fuel level was off. IE, if fuel level was 1/8 inch high then you would screw the needle/seat in 1/8 inch etc.. If you tend to run out of adjustment attempting to set properly, then somethings is amiss with either float or needle/seat.

As CaptJason mentioned, once stopped after skiing etc. - check for fuel dripping inside the venturies. You can also unscrew the fuel level plug and check the float/fuel level then as well. It should be at the same level as described above.

If none of the above proves culprit,,,

I also know from experience that Holley's are quite fond of vapor locking - resultant from getting hot etc. The suggestions by wca-tim above could also help tremendously. I always ran an insulated gasket and heat shield under my Holley's (vehicle applications however - yet for same issue)