Fuel tap mod - does my bike have it or not?

Snap · Post by **Snap** » Mon Dec 07, 2009 1:53 pm

With the tank off, if the fuel tap has been switched on, should the fuel come out on its own if the fuel tap mod has been done?

I havent tried it yet but i wanted to know what to expect.

Thanks.

Post by **CMSMJ1** » Mon Dec 07, 2009 2:16 pm

yes..

Post by **ibby4585** » Mon Dec 07, 2009 2:23 pm

forgive the ignorance whats fuel tap mod? ive got mine apart at the moment ready for the tank to be blasted!

Post by **CMSMJ1** » Mon Dec 07, 2009 2:27 pm

The removal oof the diaphragm to make the tap "always on"

Commonly called the HRC tap mod...so lots of people do it and have problems..lol

not the best thing to do unless you have absolute confidence that your carbs won't have a leaky float valve and allow fuel into the cylinders. When you try to start it you can get hydraulic lock...and bend conrods etc...

Not recommended unless you are racing and suffer from fuel starvation

Post by **ibby4585** » Mon Dec 07, 2009 2:35 pm

ahh i see, ok ta Kris

Post by **Neosophist** » Mon Dec 07, 2009 2:38 pm

Yep!

As been said, it's known as the 'HRC' mod as it's detailed in the HRC book, many people think.. oooh HRC must be good and do it to their bikes when it isn't necessary.

As you are aware the VFR uses a vaccumn operated fuel tap, even if it's set to on, fuel won't flow until the engine is cranked over, this suck opens a rubber diaphram that lets fuel flow.

On the tuned HRC bikes, at WOT during racing this diaphram, even though open still restricts fuel flow slightly, this restricion is enough to starve the carbs of fuel so they removed it.

Not really recommended for road bikes. Racing bikes that suffer from fuel starvation then yes! These usually have the fuel drained from them after racing anyway so it isn't a problem.

If you do it and your carbs leak you'll fill the cylinders / oil with petrol, can result in broken engine

Post by **ibby4585** » Mon Dec 07, 2009 2:40 pm

nah wont be doing that. cmsmj1 did you have any pics of the exhaust??

Post by **CMSMJ1** » Mon Dec 07, 2009 2:55 pm

ibby4585 wrote:nah wont be doing that. cmsmj1 did you have any pics of the exhaust??

lol..am at my sisters house...my moto is at mine and I cannot get my laptop on their cack talktalk connection

I do have a ti stack in a box in the boot though

Post by **ibby4585** » Mon Dec 07, 2009 4:17 pm

how much!!

no worries i will be patient!!

duncan · Post by **duncan** » Mon Dec 07, 2009 6:48 pm

If fuel is leaking past the carbs into the cylinders then the fact that the tap is off will not make a lot of difference to the outcome because of the volume of fuel available in the wide diameter pipe between tap and carbs

Fuel tap mod - does my bike have it or not?

Fuel tap mod - does my bike have it or not?

Re: Fuel tap mod - does my bike have it or not?

Re: Fuel tap mod - does my bike have it or not?

Re: Fuel tap mod - does my bike have it or not?

Re: Fuel tap mod - does my bike have it or not?

Re: Fuel tap mod - does my bike have it or not?

Re: Fuel tap mod - does my bike have it or not?

Re: Fuel tap mod - does my bike have it or not?

Re: Fuel tap mod - does my bike have it or not?

Re: Fuel tap mod - does my bike have it or not?