Hi can anyone give me any advice on why my rvf keeps flooding?,the bike suddenly lost power.stopped to refuel & it just chucked all the fuel straight out,so carbs off.There seems to be no probs with the floats,jets are cleans so i cant see what the cause is!!!!!.just had it sorted (electrical probs) so patients are wearing thin...

did you check the float height?

william

noob question coming up
how do you check the float height, which area of the float to which area of the body do you measure ??
any pics available?
thanks

Hahaha, I knew this set of photos would come in handy! :D

Measure with the carbs at an angle so that the float only just rests on the valve and measure from the float boal sealing surface to the top of the float (at 90 degrees to the sealing surface) as so:




You can do it with a ruler but I prefer to use the depth function of a set of vernier calipers.

Druid

thanks for that druid
what should they be set at?
and how do you adjust?
i have a spare set of useless nc30 carbs to break sorry i mean to play with :)

Sorry but I don't know the NC30's off the top of my head, should be IIRC 12.5mm for the NC35

You adjust them by bending the tab on the float that contacts the valve very slightly in or out.

Druid

NC30 float height is 7.8mm IIRC.

It would also be a good idea to check the needle valve tip is in good condition,conical and sealing properly, as the float height being correct won't be worth anything if this is deteriorated and not sealing correctly. Also check the small damping spring (the pin between the float tab and the needle valve) is still springing properly as this helps create the needle valve seal.

Thanks.

6.8mm is factory level.

There is a very good guide about how floatheights work to set the mixture up

Here

Which is handy when tuning if you dont' mind taking your carbs to pieces a million times :D

Why adjust the float height?

Changing the float height changes the level of the fuel in the float bowl. The fuel height adjusts the full throttle, 2k-3k rpm and part throttle cruise, as in cruising around town, trying to be quiet... To give a scale of change, if the bike runs well when cold, but gets a bit sloppy when fully warmed up, lower the fuel level 1mm (i.e. go from 15mm to 16mm float height - remember the float measurement is "backwards").

When do I adjust the float height?

When installing a Carb Recalibration Kit tm.
When rebuilding carbs.
To adjust low rpm / part throttle operation that isn't pilot jet, fuel screw or needle height related.
When a bike starts running rich at low rpm after a mishap or
After an overwhelming gravity equalization process occurs.

Thanks guys loadsa of information hopefully should sort out problem,keep you posted....