I have two rvf 400s, one road and one track. I have had plenty of fuel tap related issues on both and am considering buying two kits from ebay which remove the vacuum part of the tap.
Has anyone had any previous experience with these kits and are they any good? any info would be much appreciated!
Cheers
Ed

Get the proper re-build kit from RO

Ive already bought 2 of the kits from rick! the problem being, my race bike runs a fuel pump and if the tap is left in the off position when the pump is running, the rubber gets sucked out from its mounting and the tap has to be taken apart to rectify!
Also, on my road bike, after a few miles on the motorway at full chat the engine bogs down due to fuel starvation!
Ps- the race bike runs the hrc mod!

edtheplumber wrote:I have two rvf 400s, one road and one track. I have had plenty of fuel tap related issues on both and am considering buying two kits from ebay which remove the vacuum part of the tap.
Has anyone had any previous experience with these kits and are they any good? any info would be much appreciated!
Cheers
Ed

Fuel tap issues are most likely the diaphram as you probably already know.

The bike is going to be 20+ years old now.

For the road bike i'd recommend getting a tap rebuild kit (Rick O does them) and service the tap and it should be good for another 20 years.

That kit that does away with the diaphram completely looks good, especially if your running a fuel pump but I wouldnt use it on the road.

The vaccum tap has gotten a bit of a bad rep to some people, mainly becuase they dont understand how it work, or expect it to last forever without needing a service (ie vaccum hose).

If you bin the road bike for example, the fuel will stop flowing when the engine cuts out, so you only have a limited amount in the carbs, if you have modded the tap you hae the potential to leak fuel all over the road, then set fire etc etc.

When I sent my vfr over a 20ft drop into a field below, it was a good 15 minutes before I could get down to it. Even though the plastics were all smashed up no fuel had leaked and a couple of cranks later and it was running.

Suggestions.

1. Road bike.. overhaul tap, new vaccum hose made of proper stuff (Honda sells it) and it should last a long time
2. Track bike.. that kit sounds good, fit a dry break connect for extra piece of mind.

Perfect, ill order one for the race bike now, plus a dry-break, good idea!
With the road bike can you suggest a way of limiting fuel starvation at top speed without the need for one of these kits or doing the hrc mod (iv tried the hrc mod but dont like the fact that the tap drips even when its in the off position). I have been toying with the idea of having the 'well' of the tap bored out slightly to improve the flow... is this such a silly idea?!

To be honest, on the road, how often are you going to be wide open in top gear for long enough to really notice any restriction in flow to actually drain the float bowls enough that the bike notices?

edtheplumber wrote:Perfect, ill order one for the race bike now, plus a dry-break, good idea!
With the road bike can you suggest a way of limiting fuel starvation at top speed without the need for one of these kits or doing the hrc mod (iv tried the hrc mod but dont like the fact that the tap drips even when its in the off position). I have been toying with the idea of having the 'well' of the tap bored out slightly to improve the flow... is this such a silly idea?!

As speedy has said, have you ever had fuel starvation on the road?

Ive ridden with the throttle pinned wide open on a slightly richer than stock 118/120 NC30 with a half system for nearly 20 miles without any hint of fuel starvation.

Most often people who say they have expereinced this are actually suffering from vaccum hose collapse, with the high suck a weak old hose can collapse in on itself and shut the fuel off until you back off a little.

The HRC kit supplied larger jets (140's range iirc) and open air box so it drinks more fuel, and can suffer from fuel starvation at long WOT.

Never seen it on the road with a working vaccum pipe and vaccum tap.

Just overhaul the road bike with a vaccum kit (DSS or Rick O both sell them) and replace the vaccum line too (again both suppliers sell both)

I'd hit up Rick O first.

Should be good for another 20 years after that without having to worry if its turned on or off or what not.

Believe it or not, i do, or at least i think thats what is happening! I regularly do a 100 mile round trip in the early hours mostly on dual carriageway. After about 5-10 minutes lying flat on the tank with the needle buried in the red the engine looses power and the revs drop. Rolling off slightly, the bike maintains about 12000rpm but wont rev any higher. But if i slow for a mile or two and then open it up shes straight back up to the redline!
The tap has been fully rebuilt and the vacuum hose replaced, so im left scratching my head once again! My bike has been on the rolling road and had the jetting tweaked (not sure what jets) if this makes any odds!

Has it been de-restricted?

YEP, ITS DEFINITELY NOT RESTRICTED!