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PHBH or PHBL carbs on 3 1/2 Sport?
Posted: 09 Nov 2015 11:44
by PaulN
Over the weekend I discovered that a previous owner has messed with the carbs on my recently purchased '76 3 1/2 Sport. Pretty much all the jets are wrong, as is the slide. I'm not even sure it's possible to get hold of slides for VHBZ carbs, but even if you can by the time the cost of all the bits is added up they come close to the cost of complete new carbs.
So has anybody fitted PHBH or PHBL carbs? What size did you use, and what jets, slide, floats etc work?
Many thanks for any help anybody might be able to give.
Re: PHBH or PHBL carbs on 3 1/2 Sport?
Posted: 09 Nov 2015 14:52
by AntietamClassicCycle
Slides are available, though definitely not inexpensive.
http://www.dellorto.co.uk/shop/dellorto ... -26-slide/
Re: PHBH or PHBL carbs on 3 1/2 Sport?
Posted: 09 Nov 2015 16:16
by EVguru
What jets and slides are fitted?
It's not uncommon to change idle jets, atomisers and main jets to suit modern fuel. Later bikes used a different slide cut-away and that can be an alternative/addition to changing the idle jet.
Re: PHBH or PHBL carbs on 3 1/2 Sport?
Posted: 10 Nov 2015 07:25
by hendre
check my PHBL struggle for a reference, the middle setup worked fine for me!
http://morini-riders-club.com/forum/vie ... phbl#p7838
Re: PHBH or PHBL carbs on 3 1/2 Sport?
Posted: 12 Nov 2015 21:56
by PaulN
Thanks Antietam. I 'phoned Eurocarb and only one of size 30 is available. No size 50s, which are the standard for the year I believe.
Currently fitted are:
Slide: 40
Needle: L3
Main: 112
Pilot: 45
Choke: 50
Atomiser: CT260
However impatience got the better of me so I bought a pair of PHBL26s with Eurocarb's recommended settings, which are as per hendre's centre column, except for the needle which is a X23
I'll let you know how I get on.
Thanks all for the suggestions, Paul
Re: PHBH or PHBL carbs on 3 1/2 Sport?
Posted: 13 Nov 2015 06:34
by PaulN
Should have read PHBH26s ...
Re: PHBH or PHBL carbs on 3 1/2 Sport?
Posted: 13 Nov 2015 09:31
by EVguru
PaulN wrote:
Slide: 40
Needle: L3
Main: 112
Pilot: 45
Choke: 50
Atomiser: CT260
A 40 slide helps lean out a rich progression mixture with modern fuel. A 30 or 40 slide has less cut-away and can be turned into a 50 or beyond.
Needle, no idea, I don't have the charts to hand
Main; stock size for a Strada, may work well for a Sport with modern fuel.
Idle/pilot jet, about right for modern fuel, I go as low as a 40 on some bikes, but the slide makes a difference too.
Starter jet; stock, not very important.
Atomiser; again I'd have to look at the charts, affects midrange and transient response.