dellorto pilot jet help

[leehuggy72]

shaun the carb is a dellorto 28mm phbh bd air and idle screws on right side as you will know...

you say its not what i've said, so what is it then cos you've lost me

[sean brady scooters]

and youve lost me matey i,m afraid..
the 28 mm phbh carbs have only a pilot jet but no changeable tube...as far as i,m aware...

[wack 63]

Hi Sean, Ive just had the pleasure NOT of setting one of these PHBH's up on a T5 152. The carb is obviously off an auto as all the jets are different,the idle has a deeper head and an emulsion jet inside the idles housing. The atomiser is a BN series ,needle no markings, brass jet in one of the mouth feed tubes,oil feed in body,45 slide and screws on the right which on a Vespa are a pain to adjust.

[sean brady scooters]

ha ha ,I think i,ve sussed out your probs...
your delly 28mm phbh bd is off a twist n go or bike as you say...
it rubber mounted but does have the tick over screw and air screw on the right hand side as looking down it....
i,ve got one in my hand now ...this one is off an aprillia 125...and it does as you rightly said have a thingy under the pilot jet..and also an oil feed spiggot..which should now be blanked off .
no wonder you found it a pain to set up ...as there are a couple of other differences too compared to the usual phbh carbs sold and used on scoots...
and yes you are correct that these use different pilots and float heights etc as they are intended for pressurised fuel circuits...i.e ...fuel pumps /or vacuum pumped..

anyways ...i,m just glad you have sorted it matey...

[leehuggy72]

anyways ...i,m just glad you have sorted it matey...

Thanks for the reply sean,

i still couldn't get it to work even after blanking off the oil tube ha ha

it would p155 fuel out of the choke when kicking the scoot over, went back to my keihin as this would at least run..

are they to different to a normal phbh ??

[Andy Pickering]

i still couldn't get it to work even after blanking off the oil tube ha ha

it would p155 fuel out of the choke when kicking the scoot over

Auto carb...!!stripped and cleaned one recently and like Sean said theres all sorts of s**t going on with them dudes..any chance of getting hold of a proper 30mm PHBH carb which if you can you can sort it pretty quick mate..