OutdoorKing Repair Forum Forums Repairs and Maintenance Questions on Walk Behind Lawn Mower Frames Victa Lawn Mower Frames Lawnkeeper Chonda Carburettor Issues. Help.

After fitting another starter, I now have encountered two problems. After putting fuel in it now drips from the carburettor and the fuel line is not the culprit. Of course after taking off the cover, the dripping stopped but resumed later after reassembly.
It is hard to start but gets there after persistence.
Also the butterfly for the choke is very stiff. Is that normal or should it move quite freely by that plastic tab my finger is pointing to at the front of the carburettor?
This mower is proving a headache since I found it and it is all to do with the fuel system.

If it isn't the fuel line then it is the needle and seat or the float is not shutting the needle fully

I also have a Chonda which has had both those problems at various times. The fuel dripping was a small piece of rust between needle and seat which comes from a rusty bottom of the float bowl. I just cleaned it and scraped the rust off the float bowl. No further problems.

The choke issue also happened. Just stiff and not coming on properly. I just sprayed all the linkages with WD40 or similar. Now I do make sure the choke is fully before trying to start. Sometimes have to push it a little further on. They will not go unless the choke is fully on.

I had the starter issue as well. I just lubricated the pawls on the starter so they fly out properly.

Other that that its been great and usually very easy to start.

All the best
Jeff

Thanks for the leads you two. When I collected the dripping fuel I noticed it had a slightly cloudy appearance, suggesting water contamination. Can the carburettor tolerate a certain amount of the unwanted H 2O? I just poured a drop of metho into the tank in the hope that will remove any traces.
The mower, whilst undercover, has been splashed with water a couple of times due to overflowing blocked guttering during heavy sustained downpours and it seems the vented fuel caps allow water ingress into the tank if enough drips over them.

If there is something stuck under the seat I think you will have to remove the carby to clean it out and there is no guarantee that will stop the leak, it is a case of you have to try that first

Yes you will have to take the carby off and clean it thoroughly.

I am reminded of the many issues plaguing the old Zenith carbys on Southern Cross (and some Victa) mowers. Generally the problem is the initial valve seat, in which case either: 1) no fuel will be getting into the bowl at all if it is blocked or the valve spindle is being held in an upright ("closed") position due to dirt or wear, or 2) too much fuel will be getting in and flooding the carby. Again this can be caused by dirt/blockage or just plain wear and tear. Sometimes a small amount of hydrocarbon sprayed on the valve will help free it up again. Try a simple gravity test. When you inspect the valve, try tipping it up and down and watch to see if the valve spindle is sliding up and down (or in and out) under the influence of gravity. Also, there is sometimes a very small sealing washer in there that may be perished or missing altogether. If this has broken down it may be what is blocking the valve.

Another problem is with the floats. I could not work out why one of my carbys kept flooding. One day I inspected the float and noticed a tiny pinhole. Placing it in a cup of water I pushed it down and sure enough it started to release a string of tiny air bubbles. In my case the float was made of brass so it was a simple matter of soldering up the leak and sanding the patch down with some fine emery paper until it was smooth again.

Take the main jet out and make sure it is clean. Blow air through all of the jets and holes in the carby. Use a very fine length of copper wire or a pin or needle to clear any blocked holes, but be fairly gentle about it.

Occasionally if a carby gets badly worn it will start leaking fuel out of some of the hinge and screw holes. In this case you may need to seal the bottoms of these holes on the outside of the carby with something like Pro-weld or JB Weld. But make sure you do not interfere with the movement of the hinges and you can still take the screws out.

Good luck. These are just some of the issues I have had with old carbys and thought they may help in your case. It is really not that unusual for an old carby to leak a bit of fuel when you first try to start the motor. Generally this is not a big issue unless the fuel continues to leak once the motor has started and the choke has been turned off.

OK. Used it to mow my lawn front and back today. No petrol dripping any more. That's good. Will only start from cold with the choke butterfly valve fully closed. Won't open on it's own. Have to open it myself by that black tab I pointed to in the picture.
I can live with that but would like what I presume to be an automatic choke system, to work as it should.
Now another problem is over revving. The lowest I can get it to do before cutting out, sounds like the highest revs it should be. When I move the throttle forward it sounds like the sky is the limit if I push further.
I would like to be able to operate it at lower revs as it is too loud and unnecessarily fast.
I presume there is a problem with the governor or there is an air leak. It could be linked to the choke function as well. There is a hose that leads from the rear of the carburettor to the crankcase and this was missing when I found the mower, so I cut a piece of garden hose to fit in it's place. This could be the problem if it isn't sealing enough on either end. It seemed to go on fairly tight but might need to fit on more tightly.

Can you control the revs by moving the governor arm, I would say the governor spring is not fitted or working properly. The hose you replaced is the crank vent and won't be the cause of the problem. One reason why the leaking has stopped is that now it has fuel in it to swell the viton "O" ring and probably the tip of the needle

Yes I thought running it would probably stop the fuel drip after you guys said it had something to do with the carburettor needle, and it did.
I have no idea which is the governor arm but I did examine the various arms and linkages on the side of the motor and could see two springs present. Does the arm that links to the choke butterfly via a rod normally have a spring? I could not find any spring attached or any holes for a spring in this arm. It feels unsprung when you move this arm.