Got a bit of rush job. I have to make a "visa run" to the Thai border on Monday, when my visa expires. My NC30 has a problem. A couple of weeks ago the small diaphragm in the fuel tap perished, and the tap was spilling fuel from the overflow spigot.

A new diaphragm is on the way from Rick Oliver, who posted the part asap. It hasn't arrived yet, and in case it doesn't arrive in time, I need a back-up plan to get the bike running. What's the best option?

Is it safe to run a fuel line from tank direct to the carbs? I believe there might be a fire risk in doing so (fire can pass unimpeded from engine to tank), and I'm not sure whether the carbs will work with "gravity flow" rather than using the vaccum tube for "demand" flow.

Any ideas? I need the bike for the 300 mile run on Monday. Afterwards, I can wait for the correct part to arrive.

If the carb float needles are working as intended it will be fine, they'll stop more fuel than needed flowing into the carbs (and subsequently overflowing).

If your float needles don't seal properly it can be potentially catastrophic to the engine - the cylinders can fill with fuel and you'll bend the rods when trying to start it (it does happen!). Turning the fuel tap to 'off' will help prevent this.

The 'hrc fuel tap mod' (google it!) is simply the removal of the diaphram, it changes it to gravity feed. I used it for years on my track bike, but it had a fuel line disconnector which gets around the potential problem of flooding the cylinders.

use a small piece of pipe from the over flow to the breather, i did this when i did the HRC/vacuum hose removal, the U piece of pipe was to offer piece of mind to stop any leaks that may occur.

Hmm.

Temporarily.

Remove the diphram, then link the breather and vaccum spouts together with a secure piece of pipe, make sure to put clips / zip tie etc on as if they come off it'll leak fuel.

Dont' forget to block off the vaccum pipe that comes from the engine else you'll have a vaccum leak.

Remember to turn tap OFF when not using bike.

Should be fine for a temporary fix.

Thanks lads, that's perfect.

I recently serviced the carbs so the float needles ought to be okay, but I'll be sure to turn the tap to "Off" before leaving the bike.