Hi all, Im after somepearls of wisdom, Just taken my bus into work to do a few bits and when i went to check the oil level, it was up and therewas a smell of fuel. I have 2 x twin 40 dells on there, and as i have no choke have to pump the throttle to start her up. I havebeen starting her up and running her for a few minutes over the last few months, but hasnt done a decent run since last september. Could fuel have just accumulated as it has had a run, or does this sound more sinister? any thoughts appreciated. Im draining the oil overnight, so should be fairly clear of contam oil, new filter is ready too, i just want to try and avoid whatever has happened, happening again. I was also thinking maybe free flow on on of the carbs, so if things are still dripping in the morning, lifting the carbs, turning the fuel pump on, and in my theory this should get the carbs pressurised, and if any leaks, should show if i put some dry rag between the carbs and the manifolds!!
forgot to say, everything seems to be running fine, pulling well, not popping or backfiring, and didnt seem sluggish, and wasnt smokey, so im thinking its less likely to be a carb issue.
Ok first of all lets not assume the worst. Compare the oil you drained out with fresh oil? Is the consistency the same? Does one feel thinner than the other? Take the drained oil away from the van and smell it outside? Does it still smell of petrol? Dont forget these vans have an overcomplicated tank venting system, almost as bad as a T25!!! The obvious thing is those big bugger carbs are pouring so much petrol on startup , it could be getting past the rings before it fires?
Oil definately still stunk when i put in the waste drum, so it was contam. im tihnking the big carbs too, as they are fed with a leccy pump, and i HAD been pumpmig a few times prior to turning the engine, to make sure it fired, so i think my bad there.
i have only recently done all the fuel lines, so im wondering if a have dislodged something that is now in a carb, hence my thought on lifting the carbs and seeing if theres any fuel leaking by. not fancying stripping the carbs though!
If not you need one as the high fuel pressure will force fuel past the float valve and once the fuel bowl is full The only place the fuel has to go is down the inlet manifolds After that it seeps from the combustion chamber past the piston rings and straight into the sump This has ruined many an engine very quickly as the petrol thins and brakes down the lubrication properties of the oil
I had the same on my imported bus and found it to be the fuel pressure regulator had been disconnected from the vacuum circuit. Mine is the fuel injected model though and so have the pressurised system.
I had the same problem, as paradox has said earlier, floats not closing off fully. Remove ya air filters nd shine a torch down and you might see one that's dripping. It's then just a case off opening up the chamber and giving the float a little bend down so it shuts off earlier.
What fuel pump do you have? some pumps aren't anti-siphon, so it could be fuel dripping through the carbs while you are parked up!! As the others have said, you need a fuel pressure reg with dells, as they don't like more than 3.5psi... I usually cheat, as pressure regs can go wrong, and just use a 3.5psi rotary fuel pump This^^ For the oil level to have gone up, it's gonna be overnight siphoning... not start up pumping!!
Why is using a pump that's rated correctly for the carbs cheating? Surely using a pressure regulator is cheating? (unless you have the standard mechanical pump)
Appears to be the float needle vable is letting fuel past when closed, looks a little worn, sonot really a surprise, I have a pressure reg after the pump already, I tried cleaning up the float valve and it just made it worse after cleaning Any recommendations for carb rebuilds in west london area??
buy the kits and do it yourself, otherwise it'll cost you £300+ for a pro rebuild... http://www.dellorto.com/merchandise...artNo=DRLA40KIT&CategoryID=1&PartsectionID=53 I don't think you'll find them cheaper than that!!
I bought a lot from euro carb this afternoon before I saw your link, ta I'm happy to rebuild the carbs myself, I'm just concerned about 2 ball bearings I found today in each carb, they had a spring and what appeared to be a floating weight that didn't contact the screwing had to undo to find them!! Does the lump of brass hold the ball down ??
"a floating weight that didn't contact the screwing had to undo to find them!! " Could you explain that in different words FB.
