Hey guys I have a little issue with my RVF400, turns out she doesn't care if the fuel tap is on "off" she just doesn't wanna stop. I've even tried unplugging the vacuum line, sure she runs a little messy with that off but still won't stop.
I suspect that it's the fuel tap itself but just wondering if anyone else has ran into this at all?

Had a couple of leaking taps all part of the fun with old bikes can be disastrous if you have a sticky or worn float needle as well.

fuel tap is fucked - so get it fixed with a new diaphragm kit.

I have the same issue. I don't think the kit fixes the problem, only the vacuum side (please correct me if I am wrong). From Rick Oliver:

"The kit will do nothing to stop the on/off/res side of the tap leaking but once the diaphragm side is working correctly that won`t matter as the fuel will be cut off before it gets that far."

To fix the on/off/res side Rick has an as yet untried kit from one of my suppliers which is supposed to fix the on/off/res side of the tap but it`s just a set of o-rings (4 small plus 1 large) not a one piece moulded seal like the original and obviously it requires you to drill out the original retaining rivets and tap the holes for small replacement screws to hold it all together again.

I took my tank off and was surprised when it didn't flow fuel at all with the vacuum hose disconnected. A quick inspection of that side of the tap revealed the seal was in excellent condition. So, I put it back together and the problem has gone away.

Any ideas of where I'd pick up a repair/replacement kit guys?

Rick Oliver is the man.http://www.rvf.dk/rickoliver/

contact details at the bottom.

I had this probem with my NC30, it was an intermittently leaking fuel tap. My advice is you ought to get this sorted ASAP because what happened to my bike is the float valves were not closing properly so fuel filled it up over about 24-48 hours standing after a ride. I mean it filled up the entire engine and carbs, from the sump to the top of the velocity stacks! Happened five times before I sorted it, I ended up throwing away almost £200 worth of oil and god only knows how much fuel. Ugh.

AdrenalineJunky wrote:I had this probem with my NC30, it was an intermittently leaking fuel tap. My advice is you ought to get this sorted ASAP because what happened to my bike is the float valves were not closing properly so fuel filled it up over about 24-48 hours standing after a ride. I mean it filled up the entire engine and carbs, from the sump to the top of the velocity stacks! Happened five times before I sorted it, I ended up throwing away almost £200 worth of oil and god only knows how much fuel. Ugh.

Did you fix the float valves too or just the tap?

Did you fix the float valves too or just the tap?

Hi neosophist, yes I replaced all four needles and all four seats with new pattern ones from David Silver, also replaced all four floats with second hand ones from royster81 (legend!) cos mine were leaky. First I did the valves, then it happened again; then I did the floats, then it happened again; then I replaced the fuel tap diaphragm, and it happened again; and finally I replaced the tap with one from a bike breaker, and it hasn't happened again! I don't mind about going through evrything in the carbs before getting to the tap that was causing the flooding, at least now I have all-new carb internals and everything set up right. The bike runs lovely now, loads of power, no flat spots, and gets +60 mpg if I stay below 7,000 rpm and it falls to 48 - 55 mpg if I cane it (which I do)

AdrenalineJunky wrote:

Did you fix the float valves too or just the tap?

Hi neosophist, yes I replaced all four needles and all four seats with new pattern ones from David Silver, also replaced all four floats with second hand ones from royster81 (legend!) cos mine were leaky. First I did the valves, then it happened again; then I did the floats, then it happened again; then I replaced the fuel tap diaphragm, and it happened again; and finally I replaced the tap with one from a bike breaker, and it hasn't happened again! I don't mind about going through evrything in the carbs before getting to the tap that was causing the flooding, at least now I have all-new carb internals and everything set up right. The bike runs lovely now, loads of power, no flat spots, and gets +60 mpg if I stay below 7,000 rpm and it falls to 48 - 55 mpg if I cane it (which I do)

ahh plenty replace then... but

with working float valves it shouldnt leak fuel at all... even if you leave the tap on. if its still leaking then something is wrong and the float valves are not sealing..

this might not seem like a big issue as you can turn the tap off but depending on how bad they are leaking you can overful and run the engine too rich as the float height of the fuel will become too much...

worst case scenario is it dies at the side of teh road and wont run again due to fouled plugs...

my zxr didnt have a vaccumn tap but i never turned that off and it doesnt leak fuel, nor does my little 60s scoot, the float valves are doing their job and sealing the fuel supply, this is important for correct fuel height when running, especially if your idling for a while, ie stuck in a traffic jam etc.