Monday, March 23, 2009

Outboard Motor Trouble Carburettors Part Two

Two posts back I showed how I removed the carbs from my outboard motor.
It was relatively simple.

Here I will strip the carbs and clean out the jets and clean the bowl as well as check that the float works properly to open or close the needle and seat that allows fuel into the carbs' bowl.

Here is where we ended off last time - carbs freed off the motor:

Next loosen the four sckrews that secure the bowl onto teh carb - these are always found on the underside - it gets a bit messy with some pertol spills so have a tray to mess into.

The float(orangish ring) should freely move up and down with a pin attached to the needle that blocks the fuel inlet when the float rises higher than a certain level or opens when it is below a certain height - the better designs have a permanen connection linking the the pin to teh float that prevents jamming of the needle in the shut position hence starving the engine of fuel.

One star(phillips) screw hold the float in place with a small pin on which the float swings. Remove this to free the needle and give access to check the cavity from where the needle came to inspect for dirt - blow it open with pressurized carb cleaner or compressed air.

In the middle of teh float are the jets that restrict/control the feed of fuel to teh engine - the one is brass and the other is under the black rubber stopper next to the brass jet.

Now I spray carb cleaner into each of the jets - first the main jet (whcih should also be removed and checked for dirt), then the one under the black stopper which can also be removed from its recesed position. Make sure to replace them and tighten them when finished lest you begin the process from the start again!!

Next I clean the seat for teh need that cotrols fuel inflow by jetting compressed air through it or the carb cleaner.

Here I hold a jet to show the orifice through which the fuel flows. THis should be totally open or clear - quite often one finds a piece of dirt on one of these.

It is also a good idea to clean out your fuel tank/s from time to time to get out water and gummy muck that can form in pertrol.
A fuel filter can be found on essentially all motors - cleat out too to get rid of dirt and water.

THis procedure has save me thousands of rands in mechanic fees and has helped me out at sea on three occasions. I would advise first doing it on land though and note all the tools you need - keep those in your boats toolkit, along with water displacement fluids and even carb cleaner.
Do not smoke next to the pertrol - especially at sea!

1 comment:

Anonymous said...

Very helpfull great description, saved me 125 bucks. Thanks for the photo's