47 Hammond Street
Hamilton   Victoria   3300
(03) 5571 2115 bob@precisionmarine.net.au

Carburettor Problems

Holley Carby Flooding

At the start of a new skiboat season many inboard skiboats suffer from fuel flooding.
There is a few possible causes and often created by long time standing in storage.

Where you are using square bore model carby such as the 600cfm and the 750cfm the fuel level in the bowl should just come up to the bottom of the site plug hole in the side of the fuel bowl when the fuel is up to operating pressure which is achieved by turning on the ignition if an electric fuel pump is fitted or where mechanical fuel pump is in place starting the engine is required or attempt to start.

Most engines start easier after a long spell by pouring a small quantity of petrol down the carby, depress the accelerator to guarantee the fuel drops down and all is operating correctly.This should allow the engine to fire and run for a short time. Repeat this procedure if necessary. If the fuel flows freely from the hole servicing or adjustments are required.The carbs like the 600cfm, 750cfm have external float settings.

With the spreadbore models such as the 650 cfm removal of the fuel bowl is required to set the float level.

Some reasons for flooding:

  • Corrosion from condensation during off season
  • Carby float leaking
  • Float level requires adjustment
  • Needle and seat assembly requires replacement
  • Needle stuck to seat
  • Needle and seat assembly o ring needs replacing (eg.on 600cfm, 750cfm models)
  • Carby gasket kit required

At no time should you continue the use any boat knowingly that any amount of petrol is leaking anywhere into the bilge of your boat.

The above info is only personal views put forward to assist skiboat owners from Bob at R & M Precision Marine

We stock most parts to service most Holley carburettors.


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