Dellorto PHBH 28 Carb Jetting?

[rog60]

I've looked through the Lambretta carb setups but can't seem to find anything relevent and as I've just 'acquired' an 'as new' PHBH28 am asking for advice on jetting:-

OK. Setup is:
Casa 210 top end
Sx150 gearbox
ignition 19DBTDC
18 x 47 sprockets
42mm Clubman
Carb to breathe through airhose and foam filter.

Current carb jetting:-
Slide........40
needle......X2, 3rd clip down
Atomiser...AV264
Main Jet....105
Pilot jet......60
Choke jet ...70

I propose to raise settings: (from a Mugello 225 and similar exhaust/filter)
Main jet to 122
Needle to 2nd clip down
Atomiser to AV268
Choke to 60
Pilot jet to 50

Any better/more economical suggestions much appreciated

[J1MS]

No expert on a Casa 210... Have never run one, but I have seen the porting arangement... A 268 needle jet might be too rich, a 266 might be nearer to right, maybe with possibly an X7 needle on that carb using a foam filter thats running under the panel... the main jet 122, I should think would be close enough to get it running...
I think a 268 and X2 would choke up at low to mid revs quite a bit.. Al at Diablo is probably your best bet for good jetting details, or Mr Brady...

[rog60]

Thanks J1MS. I realise that the Casa 210 is a bit of an unknown at this time but a Mugello 225 is the nearest in terms of port arangement etc that I can think of.

I'm still getting the tinkley rattle but as per suggestions can see no signs of anything un-toward so am proceeding with the 'running in'. I am impressed with the torquiness (is that a word?) of the kit which makes mincemeat of the big 3rd-4th gear jump (SX150 gearbox) that the Indian iron barrel (200cc) struggled with. Starts almost first kick hot or cold etc.

But I'll wait for the fountains of knowledge to perhaps contribute..........

[J1MS]

I did a few 190 conversions a while back & one of them was for my old mate Eddie (RIP) I did his barrel the same as the others, same port timings, same port widths... It ran fine for a couple of years but always had a slight rattle...I had it apart changed a few things new small end bearing, put a slightly larger shamfer on the Inlet (bottom edge) same angle, just slightly longer to reduce the chance that the inlet was snagging the lower edge of the piston on the down stroke. Put it all back together, still rattled.....

Turned out to be an incorrectly machined little end eye on the con rod... to much clearance causing the rattle... as I said It ran for a couple of years... Last time I saw it it was on John Illings work bench for a service (still had the same rattle), but it now belonged to someone else...

[rog60]

It's a Mazzuchelli crank and it also was used with the Indian 200 setup, but I never noticed the rattle then.....perhaps it is down to ally v cast acoustic differences? The little end bearing is a tight but firm fit to the small end.

[Special X]

118/120 main
40 slide
AV266
X7/X13
52 idle

Should be well in the ballpark for starters. Full throttle may be rich tough and you may have to come down to 115 main.

[soosh]

If this helps,ive got an iron barrel dyno`d at 115 main (open mouth) AV264,X13 2nd clip,55 pilot.
That was with a PM Tuning pipe and at 19 degrees.

[rog60]

Thanks. That gives me quite a bit to start with, I'll order up some bits and see how we go.
That's what is so great about this site, the sharing of all that knowledge

[Diablo]

Yes agree with those carb suggestions. X7 and AV266 seems to work very well on a lot of different Lambretta applications.

[rog60]

Thanks Al.