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Dellorto woe's

Posted: Tue Nov 21, 2006 3:15 am
by yellerduck
I have a set of Dellorto PHF36's on my 1990 750 Sport. Does anyone have a problem with a small teardrop of gas developing underneath the carb float bowl nut after the bike sits overnight? I have replaced the fiber gasket located on the float bowl nut twice without any success. The gasket appears to allow the gas to permiate (sp?) it as it looks wet. Does anyone have a solution or suggestion? I am thinking gasket maker around the float bowl nut maybe?

Posted: Tue Nov 21, 2006 10:35 am
by Finnpaso
At least my 40 Dellortos have also rubber gasket in top of float bowl, what can get out very easily from its groove and surely then get little broken, what can cause drops, but that gasket in bowl empting nut can also be bad material. Its very easy to make such new from right material. Try ask from local gasket shop, what material can handle gasoline. Easy job, but need some gasket cutting tools... I have! :laugh: :laugh: :laugh: Sorry, my company have, but easy to borrow! :funny: :funny: :funny:

Posted: Tue Nov 21, 2006 10:48 pm
by DesmoDog
I've got the same problem on the 32's on my 750 GT. I tightened them up a bit more and it seemed to help a little, but it's wtill weeps. I'm not so sure I want to tighten them any more than they are...

Posted: Tue Dec 26, 2006 3:38 am
by yellerduck
I have determined that the fiber gasket at the bottom of the float bowls seems to permiate the gas and causes the tear drop of gas overnight. I took the fiber gasket off and put some gasket maker. It seems to be holding but I really don't understand why the fiber gasket doesn't work. Does anyone else have this problem? Also, I have another question needing advice.

I'm still trying to sort my Dellorto PHF 36 carbs. I have replaced a few things in an attempt to get it to run better. Floats, needle valves all gaskets. The problem I am having is that I have to adjust my air mixture screw out on my left carb four or five turns to keep it from backfiring through the air filter. After turning out the screw this far, it doesn't backfire but it runs really rich. Plugs keep fouling. Any idea what I need to look at to fix this? Thanks.