Scooterotica

I run a PHBH 30mm on solid mount CDC manifold. I have a plan to get the solid mount machined down and fit a new rubber mounted carb.

The solid mount carb works quite well (it has never had occasion to fall off!). The solid PHBH 30 is now old , well worn and has problems getting a tickover, slide is loose and worn threads on throttle cable cap. The manifold is also long and would benefit induction if shortened (it has already been flowed to the barrel so want to re-use).

When I come to putting on a new carb would there be a noticeable difference between a new PHBH 30 roundslide (possibly the powerjet) and a 30VHSH flatslide?

I have a VHSH already, it's jetted for an Imola I believe, although, never fitted it. The new rubber PHBH could be set up same as existing carb and run well if not a little better with shortened manifold. Current set up has been dyno'd so I know it's ok. To use the VHSH would result in another series of dyno sessions...for what extra gains?

Would I see major benefits using the flatslide(once set up/dyno'd) over a PHBH?

Currently:
RS Tuning Suzuki 190 (TV Barrel and rodded crank)
30 PHBH solid mount
44mm RS Clubman
AF-Ducati with static timing set at 19

want to try:
Chiselspeed M-tech advance/retard
Mickek MK ?? (Looks like a DJ)
and a new 30mm Dellorto

Thanks

If your old carb has been fine why not get another one and save all the hassle.I don't think you would find a great difference swapping to rubber mount and as for the flat slide,I think all they do is supposed to be more responsive low down.Never had much luck with the power jet versions and tend to blank it off.

if you can get your solid mount overhauled (new slide, jets, float etc) i"d keep that on. i run one on mine, and same, never have to tighten it, no carb rubbers to split, runs great. want another solid mount one for my GP.

Thanks for both your views. I took the bike down the M1 from Wetherby today into a strong headwind, it still pulled well!

Also did a search on Flatslides V Roundslides; there's a few bits of info and lots of different views in favour of one or the other. Flatslides very good for low throttle openings and Roundslides are good when the throttle is wound full on was one of the things mentioned whether true or not, most of what I found came via motorbike forums.

I think it was a case of I had the fancy VHSH and looking at my old solid mount thought if I fitted this and that it was gonna work wonders and transform the engine.
All my mates ride fancy engined Lammy's and buzz off telling each other what upgrades they've splashed out on. I must have felt left out!

As it is I will try your suggestions of getting existing carb overhauled. I'd still like to shorten and machine the solid manifold to sit the carb closer to the barrel if that is possible and been done previous?

Thanks very much

mawso wrote:
As it is I will try your suggestions of getting existing carb overhauled. I'd still like to shorten and machine the solid manifold to sit the carb closer to the barrel if that is possible and been done previous?

Thanks very much

Give Ralph a ring. I'm sure he'd be able to shorten your inlet for you. And probably adjust it if its likely to bash the engine mount. He'd be able to point you in the right direction re: jetting too, if you put your fancy carb on it