VHSH carb rubber

[gazza]

hi need some advice please, read some post on carb rubbers as i'm having a problem with the carb popping off. I've only had the scooter a few weeks its a Lambretta Li 125 with a 186 Imola kit and 30mm VHSH Dellorto carb. It had a water hose type rubber on which kept coming off so I ordered one from beedspeed for a VHSH carb but they were out of stock but said they would send a Mallossi type which would do??? well fitted it and didn't get more than a mile before it came off again managed to get it on and back home, and when I measured the grooves on the carb and manifold compared to the ridges on the rubber and they don't match. Does anyone else have the same setup and if so what type of rubber are you using ?
The inlet manifold has Imola on it so presume its the one that came with the kit
Thanks for any help

[Cgt75b]

For a quick fix get a Stanley knife and take out the ridge, see if that helps.

Just one more thing

I didn't know Gazza was into lambrettas lol

Good luck.

[gizmo]

I use one of the lth manifolds on my imola with no issues at all

[gazza]

Thanks for the replies I tried to cut the ridges out but to no avail got about a mile from home and kept falling off. seemed to be worse once it was warm and only comes off at the manifold end. managed to get home and replaced it with the original radiator hose and managed about 10 miles with no issues. Now contemplating removing the manifold and machining another groove into it with a new rubber. failing that buy a 28mm phbh or something and swap it !!!!
where can I get a lth manifold from ?
Thanks

[gizmo]

Got mine from chiselspeed, think rayspeed do them or lth in Germany of course

[Markpm]

just get the proper stepped rubber for the carb
I'm assuming your manifold has a groove in it
AF Rayspeed will sell them as this carb is used with the RB kits
Mine hasn't came off once

[Marrsy7]

I've got same prob with my Monza 200 normally get about 5 miles an carb falls off from manifold tried the thin jubilee clip and the wider 1s no better

[gazza]

Thanks for all the replies, dont think I need a stepped rubber as both manifold and carb are the same size 34 mm the main issue seems to be that the groove on the manifold and the one on the carb are not in the same places and nobody sems to do a rubber like that. They all have the internal ridges in the same place on both sides of the rubber. A couple of days ago went approx 15 miles with no problem then yesterday did about 2 and it fell off refitted and headed back home to which it came off again. It is really annoying so I sympathise with you Marrsy7 , what type of carb have you got and is it a manufactured rubber or have you tried a piece of radiator hose ? the only thing I would say is its best to use the wider type jubilee clips and not to overtighten as this can push the carb off, they should be tighten to a point wher the carb wont twist anymore. Also check that there is nothing catching the carb to force it off like rubbing on your side panel or catching on cables etc.

[Granty]

Troops, I had the same issue, the solution to date was to move the banjo round so the fuel line didn't rub and catch on the inside of the panel.

The rubber I took off was just radiator hose and although it was on the manifold ok the jubilee clip had worn right through the rubber. I changed it for an MB rubber and it seems to be ok.

In summary it must be a moving part that's knocking the carb of, if mine was the fuel line it could be anything.

[gazza]

Thanks for all the replies think I have sorted it 40 odd miles and still feels solid just jetting issues so going to start a new thread.