ES2 carb still a problem!

Burlen told me the correct level is 1' 5/16" down from top of float chamber which comes to about 1/8 down from the top edge of the bottom cap of the carb body. That is with a horizontal carb.

My new carb dripped to start with but it seems OK now. Dirt in fuel was preventing the float needle seating fully so the level rose slowly when the engine stopped. Maybe that's your problem?

Sigh. Those carbs are often a problem with leaks due to the poor mechanical advantage of the float/float needle, unlike the monobloc which has a lever effect with its 'hinge' on the float. When your carb was reconditioned, did that include the float chamber? I doubt it. You could buy a NEW float chamber/float and needle as a last resort which wouldn't leak. A bit dear though, Surrey Cycles could supply. My brand new 276 from them has never leaked or flooded whereas a reconditioned one was so unreliable I swapped it for a monobloc.

Hi Ben, if you were a bit closer, I would have a look for you. The level needs to be just below the idle mixture screw, otherwise it will leak outpast the screw threads.

Remove the bowl and then carefully slide the float off the needle, which will then drop out. Put some coarse polishing compound

(I use BRASSO paste) around the needle to seat contact area and insert needle back in bowl, then lap the needle to seat by twisting and swivelling the needle around while gently pulling the needle up against the seat.

These carburettors do not leak if care is taken around all leak points. I have several machines with the 276/76 type units and only turn the petrol tap off when home in shed after a ride.

Be careful of dripping fuel, particularly when trying to start, as a back fire may cause a fire. Ensure you have the gauze screen (or airfilter) attached to stop any unwanted flame.

Paul.

I had to fit an inline filter (nice vintage looking ally thing) before I could stop flooding.

As I understand it, the level is supposed to be below the small overflow drain hole on the side of the carb just above the edge of the base flange.

No that I have much confidence in my own carb. I've just lashed out about £300 on a new one and it's no better than the old one. Bike is actually harder to start, and for some weird reason is not quite so lively on wider throttle openings - where the dodgy pilot circuit is irrelevant anyway.

Mine also dribbles a bit when on the stand. I tested the level with some windscreen washer tube screwed into the plug hole on the side of the banjo below the main body, and the level went straight up to the 'correct' position (as I understand it) just below the overflow hole. But then it slowly crept up higher, and fuel began to leak out - probably I need to polish the float needle. (if your is not dribbling then I suspect we are talking at cross purposes...and yours is probably OK now)

I don't think this happens on the road when fuel is being used, but I've no reliable means of telling.

I think a new clip-on 276 (jetted for 16H) will probably shortly appear on the members adverts here! After I polish the needle+seat together.

Damaged a rib and can't test it again properly until I can get it on the stand painlessly...

Ben, something not correct here, if your level is 20mm above the pilot air screw, this would make it around the middle of the intake bore, and fuel would be a gusher.

Why not take it back to the 'professional', the onewho apparently didn't even lap in the new bowl needle to old seat.

As far as the large mixing body nut length goes, I just measured the nuts onthree of my machines, and they varied from 1"to 7/8" to 3/4" long.

As previously said, ensure the tickler isn't hitting the float top.

Look up inside the float chamber lid at the small central guide hole for the float needle, unsure there isn't any thing that catches or restricts the needle movement full travel upwards.

Re the choke, are you sure that you are moving the lever so as to pull out the cable, lifting the choke slide.

Is the bowl sitting vertical and not on a lean (not all bowls are the same)

...and David, your bowl needle needs the Brasso treatment, that's a classic sign you have!

Good luck fellas,

Paul

My new 276 works OK - and certainly better than your description of your problems - I was probably just too unrealistic in my hopes. I do intend to do as Paul suggests (thanks, Paul..), andlap in the needle better. The bottom float chamber banjo is annoyingly inaccessible so I'm not keen.

I might changeback to the old carb (when my rib gets better) since I'd rather have the bike perform better at higherrevson the open road than at low revs not far from tickover - but before I do that I'll change the plug on the principle that 90% of carb issues are (allegedly)caused by ignition - and vice versa.

Ben, I am at a loss. I once had a blond hair come throughthe fuel line which was across the seat, causing the carburettor to slowly flood. I also have had the float needle foul in the guide in the bowl screw top. I have had a float with a pin hole causing it to partially sink. And the more obvious one, small bits of sediment OR the cork tap seal breaking up keeping the needle from seating properly.

AS for the other symptom, sounds like the main jet is partially blocked. All a mystery to me.

I have been through the whole list above with a 276 carb. The answer turned out to be a weak clip holding the float needle. The float was effectively free to slide up and down the needle. This resulted in occasional dribbles, occasional flooding and a refusal to rev above 3,000 rpm and it all got steadily worse.

Still, as a result, the bike got a top end overhaul and a magneto rebuild which as it turned out it didn't need. Sigh.

5 years of standing  can  give problems with carbs.  One year in damp  conditions (my garage!) and E05 left in the carb will do the same . The issue with the old 276 and similar  carbs is often the seating in the float chamber that does not respond well to a new needle and even if it can be made to seal  it has lost its level. I had years of problems with a TT type carb that was instantly solved with a new old stock remote float chamber. 

It might help if you can remove the jet block and clean the pilot circuit passages. That cured my 276 after a decade or two of (dry) layup.

I agree with David,  the jet block has an incredibly fine drilling for the pilot supply that  does not usually  respond to any amount of blowing through the assembled carb.