Club 80-90 Forums

Hi All, I recently noticed a petrol leak from the engine bay of my 2ltr a/c camper with stock twin Solex PDSIT 34. I thought it was the fuel hoses, so replaced those and also re-glued the brass fuel hose fitting into the right hand carb that's previously popped out. I couldn't see any leaks after the repairs.

I took the van out for a run and after a while I noticed poor running and the exhaust gas was rich. I opened the back up and noticed that the leak had reappeared! I've taken the airbox off and can see that the right hand carb is flooding. Petrol is pouring into it, it looks like petrol is syphoning and flowing out of a second nozzle at the top of the carb, just underneath the choke butterfly.

My initial thoughts are the float is knackered and not cutting fuel supply. I'm by no means an expert and I was wondering if anyone could give me some advise before I start any work. I guess the carb has got to come out for me to discover the problem and I know the rebuilds take 15 hours! Any advise for fault diagnostic/recommended mechanics would be welcome.

Thanks,
Will

Float is stuck or punctured, float needle/seat is damaged/worn, float needle/seat has crud in it, or the adjustment is way off stopping it closing correctly. Adjustment is made by measuring the level of fuel in the bowl, and changing the thickness of the washer under the needle seat 'til it's right.

The hole that the fuel is coming out of allows atmospheric pressure to act on the upper surface of the fuel in the float bowl, such that the difference between it and intake pressure will cause fuel to flow through the jets.

You don't need to remove the carb completely, just take the top section off, (disconnect the linkage rod between choke mechanism and the throttle spindle and take the screws out). To check operation blow thought the inlet while holding the needle lightly closed, it should take only the tiniest pressure on the needle to stop you blowing through it.

Footprint wrote:Float is stuck or punctured, float needle/seat is damaged/worn, float needle/seat has crud in it, or the adjustment is way off stopping it closing correctly.

t.

My bet you'll find a bit of rusty crud.

While you're at it lubricate the carb linkages, especially the 'ball and spring' on the rhs.

Cordialement,

Thanks for both of your help. I took the top half of the carb off and checked the operation of the needle value by blowing through. I also removed the float and checked that. Put it back together and no more flooding (yet!), so I guess there could have been something blocking the valve slightly or it's a more intermittent problem which I guess is unlikely.

Thanks again,
Will