crs_20

Thanks all for your help this has now been resolved. I checked the pressure at the carbs as Peter advised and all was okay. Turns out the problem was the needle valves. Eurocarb had fitted viton needles (meant to be better than standard brass) which for some reason both leaked. Changing to brass fixed the issue on both carbs. Straight through the MOT On Friday so another excel back on the road!

The carbs only leak when the pump is on. It is a slow leak so the float / needle is cutting off most of the flow but not quite stopping it. I spoke to Eurocarb, they reckon that it is very unusual for there to be an issue and the fact that both were doing it even less likely, so suggested that the fuel pressure was probably too high. If I can find out the thread onto the pump then I can get a Barb hose connector to plumb in the pressure gauge. Even if the pressure is ok, which I suspect it is, one possible cause will have been Eliminated.

When I checked the float heights I looked at the needle and seemed to be seating ok. The needles were replaced as part of the rebuild so should be ok in theory. I want to check the fuel pressure so I can eliminate one potential cause, as at that point the issue has to be the carbs themselves. Good point on the fibre washers I hadn’t even noticed! Will get them changed.

Hi Everyone, I am in the process of getting the Excel back on the road and as part of this I had the carbs rebuilt as I am not sure they have ever been done in the past. They were sent them to Eurocarb and the guys did a great job with the carbs looking like new. However once everything was connected up both carb's are leaking fuel through the venturi's. You can also hear the pump still ticking although very slowly. On checking the float heights they were perfect and matched the settings in the Des Hammill book. As both carbs are leaking a sensible starting point seems to be to check the fuel pressure (although never an issue before so shouldn't be now) to at least eliminate one possible cause. My plan is to plumb into the pipe just after the fuel pump to check and then remove straight afterwards. So my question is what size thread is the union that connects onto the fuel pump as pictured below? If possible I want to connect some pipe to either end of the gauge and then get some connectors to the pipe that allow me to temporarily connect it to the car. Also if anyone has any advice on what else could be causing the issue please let me know!

I have used the Mahle oc141 oil filter. Found the pressure comes up a lot quicker on startup than with other makes of filter.

Have you still got the old tensioner bearing? If so I would be tempted to try that and see if the noise disappears. Just because it is new doesn't mean that it cannot be causing the noise, I changed one a couple of years ago for it to then fall apart 200 miles later.