Del-orto carbs, help needed please

Mine’s from Haynes manual. Quite possible they got it back to front of course.

I am on holiday in Lanzarote so do not have my books to hand. However, by memory 10 gram floats are 23.5-24.5mm ( a bit of tolerance is needed, it is too hard to get it dead right).
The heavier float is about 18mm by memory and Haynes has them the wrong way round. Anyway, with what you are experiencing it sounds like you need the 23.5-24.5 figure.
You will probably need to move your needles back up to the middle notch.
All the best,

Almost certainly put the needles back to where they were supposed to be originally

Many thanks chaps, I’ll hopefully order the parts tomorrow.

What I quoted above I just read out of the Guzzi manual for the v50 II, 24mm choke square carbs. These figures may well differ from those used in other Dellorto carbs.
Brian UK2013-05-28 12:01:43

Fair enough Brian!
All the best,

Dry sootiness on the plugs could mean tight valve clearances. Don’t know about small blocks but the big blocks are very sensitive to tight tappets.DryNormski2013-05-28 20:41:13

Let’s see what happens with the new floats.



I spent some time making a “special tool” actually an old credit card with the correct height cut out when I found one of my PHF36s was 2mm (YES!) out

Yep! Good tip, and keep it for future reference

Can i hijack this thread now that the op has resolved his issue.

i read a few comments about the choke cable having some slack in the off position. is there a method online on how to check this - set-up.

i have a starting issue, which i now know is just down to the carbs being filthy. but i want to ensure when i install them again that i have done it correctly.

Slack in the choke means just that the cable is loose, and does not tension until the actual lever is pulled I always set up the chokes and the throttles so I can see the free play , as a rule about 1/4 -1/2 the length of the chrome end ferrule seems to work it is NOT an exact thing but they both need the same free play and to be honest unless it is very very cold the 850-950 often only need a flick of the choke to fire them up and very quickly off.

Some bikes do need it actually ON but the T5 and my 950 engines have only ever needed it flicked on then off as soon as it fires up

Bits are ordered, there was some confusion with the floats, but eurocarb seem to have resolved that now.

Roughly 3mm of slack, if I remember rightly. This ensures plungers are fully lowered. However do check that the plungers do actually go all the way to the bottom, as they can go sticky and then not close properly. GB recommends cleaning with white spirit. I think.

White spirit leaves no residue and the brass should keep itself clean BUT the crap in modern fuel does mean they get gummed up

I actually use white spirit to clean parts then a wee whiff of wd 40 seems to keep everything working OK

Last ones I got, 10 years ago now, not brass but some grey metal; as it happens yes one of them has gone tight. Not done complete carb o/hauls yet, still waiting to do but need to sort that out for one thing.

I tried changing my chokes to the flip type but found that for some reason they were not closing when the flip lever was back down. This was confirmed by there being no “witness mark” on the rubber pads where they are supposed to push down onto the petrol passages.
I bought some replacement cables and put back the spring-loaded pistons and all is well again.
Pair of flips available to a good home?
All the best,CylvaBirch2013-06-01 23:34:36

Just to let everyone know, and many thanks all for your input, the prts arrived last saturday, but I didn’t get chance to fit them until today, new jets, floats and needle valves, needles put back to position 2, and all appears well, they tuned up straight away, and it is a completely different bike to ride.

I’m taking it for a run to Lake Bala tomorrow, so fingers crossed !

Did you go for the short or long flips? I have long ones on the t5’s vhb30 carbs and they work a treat

I bought them from Gutsibits as being OK for my bike. Never mind.
Just cheated death this morning as I tried to nip up a fuel tank connection leak and it parted on my. I was kneeling in a puddle of petrol until a neighbour heard my cry for help!!!