Hi,
I have leaky carb. (1979 R65)
with the float bowel removed lifting the float to horizontal stops the flow, so does that mean my float may need replacing (I have flat tops). Does anyone know what they should weight - mine is around 18 or 19 g. I tried to test the float action by holding is in petrol but wasn't convinced this was a good technique.
Any help appreciated.
Tom
When I installed new floats I weighed them on super accurate lab scales at 12.495 Grams. Call it 12.5 grams. That was lighter than I expected as 13 grams is reckoned to be the standard weight.
You can run floats at 13/14/15 grams or even in a pinch at 16 grams but you are definitely on the slippery slope beyond 15 grams. Floats that weigh 18 or 19 grams are sinkers.
My old floats did the same as it happens also on flat tops but the fact that they are flat tops is not the issue and the floats are no different to the dome top Bings. Those Motobins floats are the correct ones .
You can install new floats with the carbs on the bike but yes it's tricky. Note the pivot pin is supposed to be driven out in only one direction because one end of the pin is serrated and you don't want to be driving the serrated end through both lugs and risk breaking a lug off. If you look at the installed pin carefully you should just about be able to see which side is serated and then drive the pin out from the other side which might mean removing the carbs.
