Maggo54321

As per the videos, I took the top of the offending carb off and turned it upside down and there was no fuel coming out, this indicated to me that the needle valve was fine but the floats must have been sticking somehow. Given this knowledge I swapped the tops over and at the same time cleaned the chamber as there was some crud in it. This immediately sorted the issue. Spent about an hour with them on test last night (fuel pump running and pumping the throttle and shaking them to simulate engine running etc) and I couldn’t replicate the issue anymore. I’m going to open them up again and just check all looks good. I will rerun the tests afterwards. I hear what you say about the danger, but I can only do so much before I have to trust them. I am going to investigate the automatic fire extinguishers too as I just cannot go on with the worry especially when you see the other thread and that blue one earlier today.

Cheers again guys. I’m actually booked in on a locally recommended rolling road in 2 weeks time (had to book 7 weeks lead time) so providing I can get everything back on the car and the car starting by then, I hope they will advise on the setup and give me more confidence that all will be good for long term usage of the car. Update on the car is I’m pretty happy that the work I’ve done last night has rectified my fuel leaking and I’m just waiting for oil to turn up before changing the oil and filter before putting everything back together and hopefully a successful start this evening! Fingers crossed!

£840 to get the carbs setup seems expensive to me. I’m sure I can get that cheaper locally. Or even change to EFI for that money and sell my carbs. I am genuinely contemplating the Megasquirt setup as it would eliminate all this concern of carbs for the future. Noted re oil down the bores I’m ready for the smoke!

Lol it was back not black holes. I’ve Googled Bernoulli and kind of understand now. Jesus these carbs are a pain. Shall I just dump them and go EFI??? Someone give me a good reason not to!

Yes I’m going to measure the output of the jets whilst they’re off. I read that 40 full pumps should output 15ml of fuel per carb. Numpty question but what do these back holes do? And a follow up numpty question but given that no fuel squirts unless I pump the throttle, how do carbs actually start the car and then idle unless you’re pressing the accelerator pedal?

Yes the float chambers are full and the pump is actually on for these videos. All 4 jets point downwards, I've even taken one of them out and the hole is at the bottom so there's no way it could squirt forwards. But I always thought it should squirt forwards as I've seen a Youtube video with them shooting out the fuel. Here's a better video of this happening. Untitled (6).mp4

I swapped over the tops of the carbs to eliminate things (including the floats) and miraculously it's stopped! Maybe its getting stuck somehow, but I'll keep on trying it tonight for a few hours just to get it consistently working without leaking. Someone has said that the jets (when throttle applied) would squirt fuel for 2 metres? I've tried this and the jets squirt downwards, not forwards. Is this normal? Here's video where you can just see it if you look in the venturi past the butterflies. Untitled (2).mp4

But, the needle valve is working! Here's a picture of the top of the carb turned upside down (and the fuel pump is on at this photo). Nothing at all comes out. The gap between the float and the gasket is 15mm

Right guys.......carbs on a bench near the car. Fuel pump on. Petrol pissing everywhere out of the back carb within 5 seconds, not a drop from the front one! Coming out of the front and the back (and the little hole at the top) on both chambers. Basically everywhere, explains why plenum full as well as inlet ports! Untitled (1).mp4

Ok, number 1 complete - valves opening normally Untitled.mp4 BUT - pulled the dipstick out and it stinks of petrol! Looks like an oil change is needed - have I done anything serious by this happening? Should I flush the engine oil at the same time or just a regular oil change? Any recommendations for oil type? I'm not proceeding with 2 at the moment then, I'll skip and go onto 3. Whilst I'm at the car shop buying oil, I'll get some long fuel hoses, so I can carry on with 3 off the car so I can properly look at what's going on inside the carbs

Thanks again guys. I’m only doing 2 to eliminate another issue which is timing. I’ve replaced the distributor whilst all was off so I would like to confirm that at least the engine would fire. Also I’ve had an endoscope down the spark plug holes and they’re dry, which again made me wonder if the valves weren’t opening on these ports (I know unlikely) but if the ports were opening why would the fuel be just backing up in these ports?

Thanks both. I will certainly give the float valves a full check tomorrow and even thought the needle valves are brand new I will recheck these - it’s important to know that it has done this prior to me servicing the carbs so I haven’t created this, but also the carb servicing hasn’t fixed it either (I’ve literally had every single jet out and the carbs in a 100 pieces) and it’s still doing it. So I’m not sharing your gut feeling that it’s the carbs causing this but I’m also not ruling it out. I’ve 100% got 4 PSI fuel input and a new FPR to boot. In addition to the float valve checks, tomorrow (now everything is dry) I will 1. Jack up and turn the wheel and see if I can see the valves rising with my endoscope. 2. Turn off the fuel pump with the inertia switch and spray easy start into the ports, crank it and see if I can at least get the engine to fire. 3. Reattach the carbs, press the inertia switch and turn on the ignition for the fuel pump to start (coil disconnected so no chance of a spark) and have a look through the carbs to see if I can see fuel coming through. I won’t press the accelerator at all. 4. Crank it (still with the coil disconnected) and check again to see if I can see fuel leaking out anywhere. Again I won’t press the accelerator at all 5. Take carbs off and see if any ports are full again. If dry I will repeat 3&4 but with the accelerator pumped a couple of times I will report back on all points (with pics and videos if possible). Are there any other checks I should carry out?

Everything is off now (for the 3rd time). Ideally I’m not putting it all back together until I know what’s what. I know what you mean about the floats and I will be doing tests on these before putting back together

I don't believe it does no. But it's hard to tell as I have now fixed the carb leak with new O rings on the carb spacers.

About 3 weeks ago. But I believe I’ve had a number of issues. One was the distributor but that’s sorted and I definitely have a spark. Ok timing could be a bit off but it should at least start or try to fire at least.