NC35 fueling problem

[eden.kwok]

My race bike has always done this, I make sure the tank is over half full and I don't get any problems.

Other racers I talk to with open airboxes have the same issue, you can get around it by filling the tank over half full or using a fuel pump.

Does it have the hrc fuel tap mod? You'll need it if you run an open airbox as there isn't enough vacuum present at all times to use the standard vacuum operated fuel tap.

Check to see that the fuel is turned to on (full anti-clockwise), and that the fuel breather is working properly on top of the tank.

It's easiest for me to just keep the tank topped up.

Thanks for the info. just some more questions

What does the HRC fuel tap do? and where I can get one?

You also said your racebike has always done this, I assume its happened to you a few times (running low on fuel). Did you find any long term effects on the motor. I assume it cant be good, but I thought i will ask.

Cheers.

[CMSMJ1]

HRC mod on the tap is basically to remove the diaphragm so it pours out regardless of vacuum or not.

get a dry break fitting too and use it when the bike is not being used.

A common mod by dweebs with std bikes...just because it is"HRC"...lol

Yours sounds like it likes a good drink..

[Cammo]

What does the HRC fuel tap do? and where I can get one?

You also said your racebike has always done this, I assume its happened to you a few times (running low on fuel). Did you find any long term effects on the motor. I assume it cant be good, but I thought i will ask.

The hrc fuel tap mod converts it from using engine vacuum to supply fuel to the carb bowls to using gravity.

For practical reasons you should use a fuel line coupling so that you can unplug the fuel when the bike's not being used, otherwise if your carb float needles are faulty you'll flood the cylinders and bend a rod on startup. You won't have any dramas if you remeber to disconnect the fuel.

Tap mod details here:
http://www.akhara.com/nc30/index.html" onclick="window.open(this.href);return false;

Yeah I've had those symptoms a few times, it was mostly a danger to me and not the engine when it happened mid corner! I doubt there will be long term afects to the engine if it's happened a few times but it's not desirable.

Even with the hrc mod, I still need to keep the tank topped up, but it might help a bit.

[eden.kwok]

Thanks for all the info guys.

Hey DataRacer, is your racebike running a HRC fuel tap?

[Cammo]

Yes mate.

Mine has an open airbox, you'll need the hrc tap mod with it.

I've seen different fuel coupling used. I tried the plastic moto fuel quick connectors (CRC brand off ebay?), but found the cheap o-rings were prone to breaking, not nice if you have no spares at the track.

I now use a metal fuel/air hose type quick release from enzed. Not cheap but never a drama with it.

[eden.kwok]

Yes mate.

Mine has an open airbox, you'll need the hrc tap mod with it.

I've seen different fuel coupling used. I tried the plastic moto fuel quick connectors (CRC brand off ebay?), but found the cheap o-rings were prone to breaking, not nice if you have no spares at the track.

I now use a metal fuel/air hose type quick release from enzed. Not cheap but never a drama with it.

I am having trouble understanding what fuel coupling is? cant you just disconnect the tank when you are not using the bike? or are we talking about switching in between sessions etc?

[Cammo]

Yes, all you need is something which disconnects the tank from the carbs when you're not using the bike.

You could just disconnect the hose form the carbs, but it won't stop fuel from pouring out!


Something like this will do:




I use something like this now because of trouble with o-rings on above type products. Heavy but bulletproof:

[eden.kwok]

Thanks mate, appreciate it. I will look into it.