Float seat gasket

murphus

murphus

Senior member
Location
Lost in the Midwest
I'm experiencing an issue with an 84 RGS I know others have in that I'm having to put a fairly severe bend in the float tang to get the prescribed 17.5mm-18.5mm float height, to the point it looks like the needle could catch in the slot in the tang. Comparing the original float seat fiber gasket with the replacement, the replacement is at least - if not more than - twice as thick. The carbs are on a 1984 RGS I'm putting back on the road. Not surprisingly, someone's been in there before, as two of the float seats have no gasket at all, which raises a question: Are the fiber gaskets absolutely necessary?
 
a gasket is necessary, yes, but it does not necessarely have to be made out of fibre. the original Gasket-Sets from Dell'Orto put a paper Gasket at this place I think.

If no gasket is installed, petrol might bypass the float seat and drop into the float bowel and eventually cause the carbs to leak - with all the nice and shabby possible results (including what happens with a hydraulic lock).
 
Right, hadn't thought about the risk of leakage when not running. I'll see what I can turn up as an option. I have one original gasket and might have a few more from rebuilding the carbs on my 83 RGS, with which I did not have the same issue. I'm not comfortable bending the tangs so severely.
 
The correct gasket is supplied with new float valves.  The Dellorto gasket sets contain 2 gaskets of the same size, but of differing thickness.

I find many doubled-up gaskets because the DPO was either blind or just too lazy to look... throws float levels straight out the door.

No problem bending the tangs to attain the correct levels, shouldn't be much bending necessary.

piet
 
So the gaskets in the kits are possibly wrong? I got kits and new floats, which as you note came with gaskets, but can't say I paid attention to which I used. I'll check when I get back home.
 
A quick check showed the one original fiber gasket at 0.52mm thick, the fiber gasket packaged with a new needle and seat at 0.92mm thick and the fiber gasket packaged with a kit at 1.20mm, which is the gasket giving me concern as I'm having to bend the float tang more than seems reasonable to get proper float height.
 
Are you setting the height with the valve spring compressed possibly? I'm sure you know what you are doing - I'm just thinking of anything that could contribute to the problem.
 
Sounds like variable gasket thickness.
Genuine Dellorto gasket kits?
I use a lot of these and the gasket thicknesses are very consistent.
 
Genuine Dellorto kits and setting height with the floats vertical, hinge to bottom, needle just hitting seat to close but not compressed. Installed the single remaining original gasket with one seat and the difference in seat height is quite surprising. Easy to set the float without the sense of over-bending the tang. Everything - 3 gasket kits, 3 float sets, all new jets, atomizer, needles, etc., - came from Wolfgang, per usual.
 
Piet, just noticed you said gasket sets come with two gaskets of the same size but of differing thickness. Not so in the kits I received, just a single float seat gasket of the thickness noted.
 
Definitely a risk of flooding if you leave the gasket out. Discovered I?d missed it many years ago when I was suddenly having hydro lock issues. When I never used to turn off taps.
Obviously you should have the thin fibre washers.
 
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