Petter A1 stuck float

Hi, I have just done first start up of my non working Petter A1 I bought after top end re build. I still need to get governor functioning correctly and set up carb, but I have another issue I need to resolve, so I was wondering if any other member has had same issue?

I have fuel dripping from a hole under the venturi, which I traced back to be overflow from float chamber (I think!?). First assumption was faulty float valve, but that seems ok, so I poured petrol into the chamber to look at the float. It is buoyant enough, but it sometimes "twists" in the chamber and locks up.

Has anyone had this happen (Zenith 24t2)?

One observation is that the bottom of the float is significantly dented, this could have caused the sides to buldge out, so I have knocked them in, so I don't think it is over size?. Do I need a new one?

Thanks for your help

Do you mean you get fuel dripping only when it's running? I had this with mine and stopped it by closing the air regulating screw.
If you get fuel dripping with the engine stopped then the fuel level in the float chamber is too high. If the float is damaged at all then it may not work as intended so it would be a good idea to replace it. Plastic replacements are available from several online suppliers.

Hi, thanks for your reply. Maybe when engine is running because I did not see this when assembled,
only after it was run. I can check that. What adjustment do you recommend? I read a starting point on air reg screw of all the way in then back 1 turn, and main jet all the way in and back 2 turns. Does this sound about right?

The damage to the float does not stop it working as a float (plenty of buoyancy), but I notice that it sometimes twist in the chamber and it is this that MAY be stopping it floating, but not sure if this is something common, or indeed a problem when in the engine when vibration should set it free (I tested it open on a bench). If it is normal, then a replacement will not help, hence my question has anyone else seen this?

Thanks for your help

Michael.parker4 wrote:Hi, thanks for your reply. Maybe when engine is running because I did not see this when assembled,
only after it was run. I can check that. What adjustment do you recommend? I read a starting point on air reg screw of all the way in then back 1 turn, and main jet all the way in and back 2 turns. Does this sound about right?

That's what I started with but, as I understand it, the air regulator adjustment only affects idling - so not necessary in the stationary engine application. Closing it down did sort my fuel dripping issue.

The damage to the float does not stop it working as a float (plenty of buoyancy), but I notice that it sometimes twist in the chamber and it is this that MAY be stopping it floating, but not sure if this is something common, or indeed a problem when in the engine when vibration should set it free (I tested it open on a bench). If it is normal, then a replacement will not help, hence my question has anyone else seen this?

I think engine vibration would prevent the float from jamming.

Thanks..... I will re build the carb and try that tomorrow

I have some documentation / cutaway diagram for Zenith 24T2 if it would be useful.

Hi, thanks, that would be very useful, I have been searching for such a diagram, but failed to find anything useful.

AndyC suggests that might be something to do with the air reg, as I think maybe it only leaks when engine is running. Not sure how of the mechanics of why this woukd be the case, but will give this a try later

Michael.parker4 wrote:Hi, thanks, that would be very useful, I have been searching for such a diagram, but failed to find anything useful.

Drop me a PM with your email address and I'll send what I have, it's a "roll your own" but reasonably clear.

Thanks Woodsman and AndyC. I re fitted the carb, and it still leaked, so not the air reg issue. I have added a copper washer under the float valve to lower the fuel level, and now no leaks, so it looks like it is fixed, but if course it could just be that the float has not stuck at the moment, and it could come back!

Engine running well now, just need to finish off the governor spring tension and done! Thanks for your help

PDF on it's way.

A1 Petrol Paraffin.
I'm having no luck in curing the carb flooding when the engine is not running. The float is in good order and does not appear to be sticking in the float chamber. I've tried all sorts even lowering the height of the float valve by adding an additional thin fibre washer. The float is slightly dished (concave) on the underside. Its not punctured.  The fuel/tank/ system is clean.
The fuel valve seats OK when held lightly closed with my finger.
I can only guess that the fuel shut off valve is worn and the needle/seat area is now too large for the limited force of the float to shut off the fuel.  I've tried repeatedly to get the valve to seat but no luck.
HELP : any ideas where can I purchase a replacement fuel shut off valve?

chuffchuff wrote: <snip>
I can only guess that the fuel shut off valve is worn and the needle/seat area is now too large for the limited force of the float to shut off the fuel.  I've tried repeatedly to get the valve to seat but no luck.
HELP : any ideas where can I purchase a replacement fuel shut off valve?

Villiers parts http://www.villiersparts.co.uk/wip.html