250c carb question

[Richard_Carrigan]

Hi all,

I'm resurrecting a 250c that's stood idle for many years. The carb needles were terribly corroded so I bought new ones and (foolishly) slung the old ones in the bin. The new needles have 4 grooves for the clip and I'm sure the old ones had three, with the clip in the middle groove. I know the old needles may have been wrong 'uns and the new needles could be modern, modified replacements that may be perfectly fine, but does anyone know a good starting point for the clip position? I know it's a lazy question but my garage time is limited at the moment and I'd like to cut the experimenting time down to a minimum!

Many thanks
Richard

[mbmm350s]

Hi Richard

Needle for 2C with VHBZ 22HS carbs is E51 this only has three grooves.
We have drawings for all needle profiles of the E series, which needle do you have?

I would also remove, clean and check the atomiser jet since the small side holes can be easily blocked. If doing in situ take care to have the throttle open to avoid damage to tip of needle by your screwdriver.

Mark

[Richard_Carrigan]

Hi Mark,

Well I threw the old needles away, so unfortunately I can't check to see how many grooves they had. I bought new ones from Eurocarb and they certainly have four grooves. The bike does have 2 VHBZ22 (HS) carbs.

The packaging which came with the needles states :
"2343 E type needle (VHB(Z) 20-26mm) - E51 needle
Variant: E51 needle".

Could I have the wrong needles, or could DellOrto have changed the spec for production reasons?Many thanks
Richard

[mbmm350s]

Richard,
i suspect the part 2343 has been updated by Del'Orto but all the critical dimensions like taper and diameter are unchanged.

I have a bag of brand new purchased in the last 3 years marked 2343 E51.
They are identical to old needles extracted from 250 2C carbs.

From the bottom my E51 measure between 60.95 and 61.0mm from the tip of the needle to the top of the middle notch. This information should help you identify the closest notch when 4 notches are present.

I will try to measure where the taper starts, its tricky without a go no go gauge or something.

Mark

[Richard_Carrigan]

Mark, many thanks for all your info. The problem has been solved! With the help of a magnifying glass and a pair of younger eyeballs we checked the engraving on the needles and it's X51 and not E51. Eurocarb had sent out the wrong needles.

I'm just waiting now for the right needles to arrive so I can attempt to start the bike for the first time in eleven years & discover what the next problem will be
Many thanks to all,
Richard