Dellorto PHBH

[Special X]

Ballpark settings are just that . . . . . it'll run and is on the safe side. AS 266 with X2 is (roughly) equivalent to the tried and trusted AV 266 X7 combo.

Answering the question from paul re his classic rapido. If you are on clip 1 of a needle and it's too rich it's a sure sign that you need to go down 1 size on the atomiser. Then try from clip 2/3 and do some plug chops to make sure it's not running weak. Slightly rich is infinitely better than slightly weak.

Sometimes dealers "polish" needles to remove the markings so the user doesn't know what needle is fitted. In fact some dealers have been known to remove the markings from all the jets so nobody can replicate their setting. Not accusing any specific dealer.

The reason for the earlier comment re don't blow someones engine up just to disagree with me was I didn't want a "special x witchhunt" to end up with some fool recommending a fatally weak set up and a beginner to think it was ok and melt down his kit. Feel free to recommend 65 pilot AV268 35 slide X2 needle and 140 main jet for a tweaked 125 if you wish though.

[paulnobodyimportant]

Just catching up with this thread with feedback. Tonight tried AV264 & x7 at p1. Just reviving on drive, felt lean. Changed needle to P2 and went for a 2 mile round trip. Pilot 48 , main 123,.reed valve and pm28 pipe. Don't anyone tell me that 48 pilot is too small, cos it ain't. Anyway felt responsive all through range and feel pleased. Will validate with plug chops b4 using in anger. Note to remind myself that I should have wrapped up tonight, was frozen when I got back.

[Special X]

Nice one Paul . . . do the plug chops though because bikes do run really crisp when slightly weak. You may find you need the needle at 2 and a half (with washer) or 3.

[nelson pk]

Just catching up with this thread with feedback. Tonight tried AV264 & x7 at p1. Just reviving on drive, felt lean. Changed needle to P2 and went for a 2 mile round trip. Pilot 48 , main 123,.reed valve and pm28 pipe. Don't anyone tell me that 48 pilot is too small, cos it ain't. Anyway felt responsive all through range and feel pleased. Will validate with plug chops b4 using in anger. Note to remind myself that I should have wrapped up tonight, was frozen when I got back.

Nope, i wouldn't say a 48 pilot is too small. I've known revvy reed valve 225's to run a 48 pilot.
i prefer the mid range to be slightly rich as this is where i spend all my time cruising between 55 and 60 miles an hour.
Hope it goes well and just remember that its not all about how quick it responds from low revs, for safety its about weather it is letting enough fuel through between 1/4 and half throttle when your "on the pipe" about 6000 revs, cruising in the mid range.
If you ride long distances with mates doing about 55 to 60 this is crucial but if you and your mates tend to ride at 45mph to rallies because you have some slower machines with you this is not so crucial and you will get away with a leaner setting.
Good luck with it.

Special X, i dont understand the comment about "special X witch hunt?"
I've never known or heard about such a thing and that was not my point.
Lets just agree to disagree on some things.
Would be a boring world if we all thought the same

[Special X]

Certainly would m8

Some good advice about being slightly rich there. I always like my engines to be rich on the needle (1/4 to 3/4) because as you said thats where you cruise. With th 48 idle it's vital to check the mixture at 1/4 1/2 and 3/4 as a smaller idle jet will have an effect all the way up tp main jet.

[Devlam]

Just coming back to this - interesting read. This will be the first time I've done this in a very long time so good to see all the views.

I'm building an Imola -- I'm undecided on exhaust at this point. Would like to fit one of the new clubmans to keep std looks, but if the bikes built before they come on the market then I may go JL3 instead.

I note on Camlam site they recommend following as initial starting set up ( I realise I will need to tweak).

Choke 30
Slide 50
Needle X2
Atomiser AV268
Main 120
Pilot 55
Starter Jet 50
Float 5gms

Back to my initial post on the value of Wasp Performance carbs (and whether anyone has used them) if I have to change the slide (there one is 40) then that seems to add on a fair bit, at which point it makes more sense to go to Camlam and let them supply one to above spec for £99.95

I'll look some more on here to see how others have jetted Imola with JL3

Thanks all
Mark.

[Special X]

Be a (very) bit rich on the the needle, weak on progression (just open to 1/8 throttle) weak at the top end, and very hard to start, due to small choke jet. I'd recommend (as a starter)

70 choke (std fitting)
40 slide . . 45 at the weakest (you need the progression fairly rich on this engine)
Needle X13
AV266/268 atomiser
pilot 55
125 main

Still, we do agree on the pilot.

Are you sure they didn't mean AS268 atomiser with the X2 needle?

[nelson pk]

Certainly would m8

Some good advice about being slightly rich there. I always like my engines to be rich on the needle (1/4 to 3/4) because as you said thats where you cruise. With th 48 idle it's vital to check the mixture at 1/4 1/2 and 3/4 as a smaller idle jet will have an effect all the way up tp main jet.

Agree 100% with that

[nelson pk]

Just coming back to this - interesting read. This will be the first time I've done this in a very long time so good to see all the views.

I'm building an Imola -- I'm undecided on exhaust at this point. Would like to fit one of the new clubmans to keep std looks, but if the bikes built before they come on the market then I may go JL3 instead.

I note on Camlam site they recommend following as initial starting set up ( I realise I will need to tweak).

Choke 30
Slide 50
Needle X2
Atomiser AV268
Main 120
Pilot 55
Starter Jet 50
Float 5gms

Back to my initial post on the value of Wasp Performance carbs (and whether anyone has used them) if I have to change the slide (there one is 40) then that seems to add on a fair bit, at which point it makes more sense to go to Camlam and let them supply one to above spec for £99.95

I'll look some more on here to see how others have jetted Imola with JL3

Thanks all
Mark.

The Camb lamb set ups are based on dyno statistics from Mr Edmunds i think you will find, although maybe a little richer to be on the safe side.
The needle/atomiser combination is purposely rich to let enough fuel through the bleed hole between atomiser and needle at high speed cruising when you back off from full throttle to between 1/4 and half throttle to cruise at 65 - 70mph.
The reed valve kits need this richness at this point because they love cruising at this speed(they're pulling the hardest here) in those throttle positions.
The 50 slide will help with the richness at lower revs.
I experiment with different slides a lot as a weaker slide will allow you to use richer needle/atomiser combos for high speed touring but dont go too weak on the slide!
However i think you will find that where ever you buy a carb from pre - jetted they will still charge for a different slide.
Best to set up with some sort of indicator (EGT, Detonation sensor etc) or go to decent dyno specialist to get it spot on.
I think there is a couple of typos there though, as special x said......choke/starter jet i would say 70 and i think you will find the floats to be 6 or 6.5 grams.
Also make sure your float height is correct 23.5mm to 24.5mm. If you dont know how to set float height download the dellorto PHBH manual, its available of several sites if you do a search

[corrado]

Choke 30
Slide 50
Needle X2
Atomiser AV268
Main 120
Pilot 55
Starter Jet 50
Float 5gms

Back to my initial post on the value of Wasp Performance carbs (and whether anyone has used them) if I have to change the slide (there one is 40) then that seems to add on a fair bit, at which point it makes more sense to go to Camlam and let them supply one to above spec for £99.95

Good luck getting a carb spec like that for £99.95, the slide alone is £29.99. I may be wrong but I'd imagine that gets you a factory carb with a cable choke conversion swapped from the flip choke.