strongy Posted January 18, 2004 Share Posted January 18, 2004 Today I removed the air filters etc to balance my carbs. I noticed that over 3000rpm there was a substantial amount of fuel seaping from around the air intake on cylinders 1 & 3 (from the base of the intakes that are held in place by 2 pieces of shaped metal and a nut - hopes this makes sense). This fuel could drip onto the battery and the dizzy and could account for the mess I get down the side of the wing and the cr*p MPG. If I remove the air intake "trumpets" is there an easily replaced ring of some description or is it more likely to be the float levels being too full inside the carb. If it is the later how do I adjust the float level? Many thanks in advance, please help me save some precious Optimax 😳 Cheers Strongy - I think its getting louder again 😬 Link to comment Share on other sites More sharing options...
millsn Posted January 18, 2004 Share Posted January 18, 2004 I assume that you've inspected the fuel filter baskets for any signs of leaks? The nut that sits on the top of the basket can leak fuel. Nigel Mills - 2.0 Zetec carbs Link to comment Share on other sites More sharing options...
Big Brother Posted January 18, 2004 Share Posted January 18, 2004 Also check the chokes are secure. Its possible they can vibrate and cause the fuel to drip out where you mention. Steve Se7en-Up! Not going to you know where with you know who in 2004 😬 Link to comment Share on other sites More sharing options...
strongy Posted January 18, 2004 Author Share Posted January 18, 2004 Thanks for the replies Fuel filter nuts are fine, no sign of a leak. How do I chech that the chokes are secure as you suggest? Does it mean removing the carbs from the manifold? Thanks again Strongy - I think its getting louder again 😬 Link to comment Share on other sites More sharing options...
Big Brother Posted January 18, 2004 Share Posted January 18, 2004 You should be able to put your finger into the trumpet and give the choke a wiggle. It should not move or rattle. One of the guys at the Phoenix had a similar problem and it was sorted by just tighening up the screw that held the choke. Steve Se7en-Up! Not going to you know where with you know who in 2004 😬 Link to comment Share on other sites More sharing options...
strongy Posted January 18, 2004 Author Share Posted January 18, 2004 Cheers Steve, I'll give that a try. Strongy - I think its getting louder again 😬 Link to comment Share on other sites More sharing options...
strongy Posted January 19, 2004 Author Share Posted January 19, 2004 No tried that and still leaking, how do I check that the float levels are correct? Thanks as always. cheers Strongy - I think its getting louder again 😬 Link to comment Share on other sites More sharing options...
Nigel Riches Posted January 19, 2004 Share Posted January 19, 2004 Here we go, if I can remember this correctly, no doubt other will point out any errors, 1. remove carb top covers with the gaskets 2. ascertain what the correct float stroke should be, (I think there is a difference between plastic and brass float assemblies) 3. hold the carb top cover in a vertical position, with the floats downwards, and the tab resting on the ball of the needle valve, the distance between the gasket face and the float should be....(8.5mm for my carbs), on both floats, correct this if required, to gain the correct dimension by bending the tab 4. correct the float stroke if necessary, for my carbs the stroke is to be 6.5mm,(6.5mm + 8.5mm) so when the floats are at their lowest point there should be 15mm between the top of the float and the gasket face, if required bend the other tab to bring this dimension within specification, repeat check to ensure that nothing was upset when any of the bending was being carried out, hope this is of some help, but can't help thinking that your floats are not at fault, as the fuel weeping would be from one carb, and both venturis, you talk of cylinders 1 and 3 so thats 2 carbs, and only one venturi on each, if you have earlier type 40DCOE carbs the choke venturis are held in place by a semicircular spring which forces the venturi tube against the upper surface of the carb casting, this in it's Italian way is to try and seal the fuel from the carb body into the main fuel inlet nozzle in the venturi, to the cylinder, if you follow, not easy to describe, but if the spring are weak, worn or broken this "seal" will not be present, and fuel can leak around the venturi casting and drip off the lower parts of the carb, have fun and if I can help any more be in touch, Nigel. 1982. 5 speed, clamshells. B.R.G / Ali. The True Colours. Link to comment Share on other sites More sharing options...
strongy Posted January 19, 2004 Author Share Posted January 19, 2004 Thanks Nigel, I haven't tried that yet, but I have noticed the following- The air intake "trumpets" were loose and rotated by themselves at mid to high revs. 2 of them had spring washers missing. I replaced these and tightened them up (not too tight - they can just about be moved by hand). The fuel leak has slowed quite a bit, but at higher revs 5000+ a small amount of fuel does drip from the inside of air intakes 2 and 4 🤔 I guess that this might be normal 🤔 Previously it was seaping from what looked like the outside of the trumpets at the bottom, presumably because they were too loose. I think that I have plastic float assemblies so I will try checking those later in the week, thanks again, if there are any other suggestions please keep posting. Cheers Strongy - I think its getting louder again 😬 Link to comment Share on other sites More sharing options...
Phil Bishop Posted January 19, 2004 Share Posted January 19, 2004 I thought they all did that. I stopped the rotating trumpet problem by packing a bit of plastic from an inch or two of electrical flex behind the clips. If it does break loose and get sucked in, shouldn't cause any damage. As to petrol leaking, it seems to vary on the day according to how I use the car. Give it plenty, and the petrol knows which way to go. It seems to leak more on cruises and over run. I sometimes think it has got less when I fiddle a bit with the carbs, but it always comes back. Isn't it just in their nature? All the best cars smell of petrol. Link to comment Share on other sites More sharing options...
millsn Posted January 19, 2004 Share Posted January 19, 2004 Mine don't leak - is this a bad thing?!! . I sealed mine with some gasket compound to stop the rattling but they didn't leak then either. There shouldn't be any fuel able to back up this far should there? Unless you've an XF. When you reach certain rpm the engine spits out as much fuel as it takes in (only an expression), I think that's at about 3000rpm, due to resonance I believe. Do you run there alot? Mine used to be an XF Nigel Mills - 2.0 Zetec carbs Link to comment Share on other sites More sharing options...
strongy Posted January 19, 2004 Author Share Posted January 19, 2004 Phil you might be right that this is just their nature, but my last tank only managed 110 miles. When I tried to balance the carbs there was quite a spillage and I know that that wasn't helping things. I'll keep fiddling and see if I can slow it some more. Cheers Strongy - I think its getting louder again 😬 Link to comment Share on other sites More sharing options...
Srcarter Posted January 19, 2004 Share Posted January 19, 2004 while you have the floats out it might be worth checking needle valves for wear as worn needle valves will cause chambers to overfill and spill fuel. Also, check that the carbs are not bolted too tight to the inlet manifold. There should be around 2-3mm clearence between inner and outer washers. Hope this is some use to you. Good luck! Stuart Link to comment Share on other sites More sharing options...
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