Tightening manifold rubbers.

[Cec DHSC]

I have an AF manifold and MB rubber holding my 26 mil Delly with a rubber elbow and remote filter on.
Trouble is, it popped off yesterday and I can't get it to stay on.
The jubilee clips seem wide enough. I've made sure they tighten down on the metal part.I haven't over tightened them so they pop off as you tighten them. I was told to recess the manifold a bit more but I didn't. Could this be the problem?

[Solid Air]

I had the same problem with the radiator hose type of carb rubber, changed to a Malossi type with the internal locating "ridges" and machined a locating slot on the manifold to match the carb rubber... no problem since then

Mark

[Cec DHSC]

Thanks Mark.
The MB rubber has ridges inside too.

[Solid Air]

Is your manifold smooth or machined Cec?

[Toddy]

Just a thought Is the carb Catching on anything like the footboard or panel when the scooters moving
Sometimes this can cause it to pop off the rubber ?

[Cec DHSC]

It does rub on the panel, come to think of it.
When you say machined Mark, do you mean the groove. If so, yes

[NorthernJordan]

I had the same problem with the radiator hose type of carb rubber, changed to a Malossi type with the internal locating "ridges" and machined a locating slot on the manifold to match the carb rubber... no problem since then

Mark

I had a Malossi one, and it disintergrated after about 100 miles.

[Solid Air]

If you've got the groove machined on the manifold already then I'd agree with Toddy that something is knocking the carb and rubber off the mount. I shortened my manifold before putting the groove in which helped. The filter is mounted horizontally and pointing towards the rear light, the elbow rubs slightly on the inside of the side panel but doesn't cause any problems.

Hope you get it sorted

[corrado]

When you say "I can't get it to stay on" do you mean that you can't get it tight enough to start with or does it pop off when riding?
If it feels solid when you fit it and only comes off when you're riding then it may be the fact that it's rubbing, as you state, on the side panel. The panel is fixed but the engine moves up and down in motion. Personally I use the radiator type as I can shorten them until there's hardly any gap between the alloy of the carb and the alloy of the manifold which in turn will move the carb away from the panel. The initial fit of the rad type is critical, if it's a squeeze to get it on then it's always going to want to push itself off, overtightening the clips will also make it want to push off. Only fit the rad type of hosing with reinforced fibre strands running through it, they're far less likely to split than the pre-formed solid rubber type of mount.

[CHRIS in MARGATE]

And only use the thinner clips or they.will ride back over the lip of the manifold.

[Adam_Winstone]

Do note that different carbs of the same sub size may have the locating rib in different positions and that your rubber needs to be correct for both the carb and manifold. Even from the same manufacturer the rib position can vary, e.g. the rib position is different on a 30mm VHSH Dellorto than on a 30mm PHBH Dellorto, meaning that one Dellorto rubber can be used on both carbs.

Most dealers don't even get this right and will simply sell you what is sitting on their shelf so don't expect getting the right rubber to be an easy task. However, when you do get a rubber that suits both manifold and carb ends then it will fit VERY well and you'll feel a lot of resistance when trying to pull the rubber off, even without clips fitted!

This same ill fitting rubber/rib issue relates to double ended rubbers and the single ended rubber boots that fit to Mikuni type manifolds/reed manifolds.

Adam

PS - I should point out that there are dealers that are aware of how important this issue is and will supply the right mount for the right application (thanks to them)

[Callummal]

make sure the grooves line up, use a tape measure

[roadrunnerian]

i use an lth inlet manifold on my ts1 no problems did have them when i used an mbd inlet always popping off catching on side panel