Carb clearance advise

[Micky Tapp]

I am struggling for clearance under panel with 28mm dellorto phbh on a breath sweet filter. The panel squashes the rubber u bend. There doesn't seem to be any change in performance if I take panel off and relieve the pressure from u bend but it is seriously squashed out of shape.
I have an atomic short read and carb exits on near side.
I need at least another 10mm any suggestions. Are the flat slide carbs slimmer? Ta Mick T

[holty]

i think i would have a look at the carb rubber first, if it has a step in the middle a piece of hose instead mght allow you to push the carb into the manifold and away from the panel, other options are shorten the manifold or shorten the stub on the carb, maybe just 5mm off the carb and 5mm off the manifold will give you the clearance you need.

holty

[coaster]

....shorten the manifold or shorten the stub on the carb, maybe just 5mm off the carb and 5mm off the manifold will give you the clearance you need.holty

It's an Atomic Reed manifold so you can't shorten it. However, I have recently fitted an Atomic manifold (Ultimate) on my Avanti and my breathsweet touches the panel but is not squashed. The rubber in mine is angled and I fitted it so that the carb angles rearwards slightly. I have used Adam Winston's trick of fitting a 30degree plastic waste pipe joint in the other end and the filter fits to that. This allows the assemble to angle just above the fan housing with the filter tucked into the gap in front of the rear strut. I'll take a picture at the weekend. It's a series 3 by the way.

[Micky Tapp]

Good replies holty and coaster many thanks. I am nervous about shortening card stub as there is lip for the atomic rubber to grip to. Coaster it would certainly help me understand if you could take a couple of pics. I didn't mention in the original post that a foam filter straight onto carb bell mouth would work, but I would lose the breath sweet bend which I believe helps stop spit back so I am keen to keep it or an alternative.

[coaster]

...................but I would lose the breath sweet bend which I believe helps stop spit back so I am keen to keep it or an alternative.

I think you might be disappointed on that front but the bend is certainly thought to provide a better flow of air to the carb than the standard bell mouth which is why they usually require a bigger main jet. I'm not actually using the breath sweet filter sock as I couldn't find the bloody thing so used a Marchant foam filter from MB that came with a selection of different sized fitting rubbers.

[Minority]

Both the PWK & Mikuni TMX are narrower than the PHBH and will give you more clearance (and are better carbs than the PHBH IMHO).
Fuel tap connection may be a problem though.
I have the PWK on a MB shorty reed manifold together with the breathe sweet. I think the PWK will fit the same rubber as the PHBH whereas the TMX may need a different size rubber connection.

[Padge]

28/30 PWK is a lot narrower than a PHBH and I agree with Minority it is a much better carb, they have a 50mm bellmouth opening and a 35mm stub opening (same as 28/30mm PHBH)

[Micky Tapp]

Wicked pics minority many thanks for taking the time to post them. I will measure my delly and then compare the dimension to the pwk. Interesting that you seem to use the bend as coaster describe. What is the adavantage over the filter without the gold pipe but just on top of the breath sweet standard rubber u bend? Thanks for your input too padge

[rosscla]

Try this way

[Minority]

Wicked pics minority many thanks for taking the time to post them. I will measure my delly and then compare the dimension to the pwk. Interesting that you seem to use the bend as coaster describe. What is the adavantage over the filter without the gold pipe but just on top of the breath sweet standard rubber u bend? Thanks for your input too padge

As you can see, I no longer have the original toolbox (midrange tank fitted, battery sits where the old toolbox was).
I have vented the toolbox door (or should I say "am venting" ) so I put the air filter up out of the dirt and in the fresh-air stream, at least that's the theory . It's also well away from the panels.