450... Which carb???

[john jupiter]

Received the carb from Dellorto UK to NYC in 6 days.

Model PHBH30AS - first impressions: has a round slide instead of the square vhb type, ALSO has mix screw and slide adjustment on the left side(i wish it was on the right but the "AS" is the only model that clamps on to suit by manifold), black plastic bowl looks kinda plasticy(a metal version is available)... Installed in a matter of minutes and fits the stock 35mm o.d. manifold like a glove.

Jetting:
268t atomizer
X8 needle
122 main jet
50 pilot jet
Idle screw and mix screw did not come set from dellorto, but the above jets where installed specifically for 450 Ducati.

I am happy to report that it seems my starting, idling issues are solved.. Just waiting for the rain to stop to take her out for the twist of the throttle test.

[wcorey]

That's interesting, they list the PHBH 'family' on the site as being available in left or right.
Going through the same issue with my 450 build, the obvious choices I already own are all left adjustments and the left side is rendered mostly 'blind' by the shock mount. At least once it's dialed in you usually don't need to mess with them again anyway...
Never saw a Dellorto with a plastic bowl either, hopefully it's ethanol compatible, I'd be inclined to ask them just to be sure.

Bill

[MotoMike]

That's interesting, they list the PHBH 'family' on the site as being available in left or right.
Going through the same issue with my 450 build, the obvious choices I already own are all left adjustments and the left side is rendered mostly 'blind' by the shock mount. At least once it's dialed in you usually don't need to mess with them again anyway...
Never saw a Dellorto with a plastic bowl either, hopefully it's ethanol compatible, I'd be inclined to ask them just to be sure.

Bill

Bill
I had a Moto Guzzi 1000SP until last year and am pretty sure the carbs were PHB30 type and they definately were spec'd left and right so that adjustments were outboard on each side.

Mike

[DewCatTea-Bob]

" but the "AS" is the only model that clamps on to suit by manifold
Installed in a matter of minutes and fits the stock 35mm o.d. manifold like a glove. "

____ It's nicely fortunate that you found a new Del.carb to do that !
I had expected that there would be other fitment issues as well - could you post any pix of how it fits clearing frame & fuel-tank ?
__ Also of interest is how you got in contact with the source and what the price was for everything.


Lucky-Cheers,
-Bob

[john jupiter]

Here are a few pics. I will have to fit a T on the gas hose to get the right side petcock hooked up. There is not as much dide clearance for the gas hose to hook into this carb as there was on the VHB. It can be done but the angle created off the petcock is a little tight.

The carb with jetting was GBP 95.00 trumpet was 18 extra and is the 60mm version which is actually a touch to long and comes right up to the battery but does fit. A metal float bowl is available, need to order the proper bolt along with it.

[MotoMike]

JJ

that looks great. Seems to have no clearance problems.

On a side note, and I apologize for derailing. I see the back end of your tach drive has been altered. Don't know if the guts are in it or not, but I had the same tach drive when I got my Duke and at some point the original aluminium disc popped out while riding and it spun the drive gear that spins the cable right out never to be seen again. the part is unobtainium so to correct it you must get extremely lucky on EBay or the like or replace the whole drive. I'd just give it a good inspection to make sure it is secure.

Regards,
Mike

[john jupiter]

Mike,
The tach drive does look like its been apart and repaired. The side you see is actually silicon and looks like it was used as a plug of some sort.. The internals are in there ans it does work however it does leak a very little bit of oil. I guess my silicon plug is attempting to replace a metal one? Maybe can have a new one machined or something...

[MotoMike]

JJ

the mechanic I knew in San Diego told me that it was fairly common for that disc to exit stage right. your previous owner must have caught it before the internals followed. A nickle fits that hole almost perfectly and I was told it was fairly common to see a nickle on those drives. I plugged the hole with a nickle sealed with RTV and staked or peened the edge over to hold it in place. Since I didn't have a gear in there trying to get out, I don't know if that would be enough to hold it in. I would think it is. Good luck.

[john jupiter]

Finally got to take the new carb out for a test drive on saturday and although i starts and idles well, it felt like it was running out of gas around 4k rpm. My needle was set on the second of four possible notches. I am thinking that raising the needle by dropping it down onto the lower notches might help richen the mix.

How many RPM is a 450 supposed to turn at redline? And how easily does the bike get there? I dont have a baseline of how it ran before.... I was under the impression it was 6500 but im not certain.

Im under the impression that The mixture screw probably wont help me at this RPM, and im looking at adjustments to the needle and the main jet, am i correct?

UPDATE 5/24: swaped the 122 main jet with my old 135 from the VHB. Now Revs through 6500rpm. Might try lowering needle one notch just to see how it feels since it does have a slight dead spot at 6k rpm. I raised it two notches yesterday before putting the main jet