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Re: NC30 Petrol Tap Arrangement HELP!
Posted: Wed Oct 29, 2008 1:48 pm
by fastdruid
I did it to our track bike then rapidly reversed it out as the tap didn't seal 100% and still leaked when turned 'off'.
I've blown an engine thanks to a leaky tap, it's just not worth it on a road bike.
Druid
Re: NC30 Petrol Tap Arrangement HELP!
Posted: Wed Oct 29, 2008 1:51 pm
by fastdruid
Stickshift wrote:If you don't disconnect the line the cylinder can potentially fill with fuel bending rods when started, it happens...
Or the sump fills with petrol and washes all the oil out of the main bearings which then die a short while later.
Druid
Re: NC30 Petrol Tap Arrangement HELP!
Posted: Thu Oct 30, 2008 12:41 am
by RVFJE
So all you guys that are running track bikes with the vacuum fuel tap still in place have had no fuel starvation problems even if you have modded airbox and bigger mains requiring more fuel?
I did mine for that reason. But also because I was (and still am) having problems with stuttering at high revs, high speeds which I thought was fuel starvation.
Must be airbox problems which I've never been able to nail the source of the problem.
Re: NC30 Petrol Tap Arrangement HELP!
Posted: Thu Oct 30, 2008 12:47 am
by RVFJE
One more thing though - if the fuel tap is always turned off but it still drips fuel down the hose into the carbs wouldn't the floats shut off fuel running into the carbs?
I mean there is no pressure in the hose,just a drip so then the fuel would just back up back to the tap - then what happens?
Re: NC30 Petrol Tap Arrangement HELP!
Posted: Thu Oct 30, 2008 1:27 am
by Cammo
RVFJE wrote:One more thing though - if the fuel tap is always turned off but it still drips fuel down the hose into the carbs wouldn't the floats shut off fuel running into the carbs?
Yeah it's only if the float valves come open, this can happen pretty easy on a track bike on a trailer though for example.
Yes, you can and might get fuel starvation problems at high revs with the standard tap arrangement on a track bike.
Re: NC30 Petrol Tap Arrangement HELP!
Posted: Thu Oct 30, 2008 1:46 am
by RVFJE
superlite wrote:You want something like this:
I wouldn't recommend running the HRC fuel tap mod unless you have to - unfortunatley some of us do and you need to be very well organised to disconnect the fuel when not in use. I haven't tried the metal connectors, but I've had touble with the plastic ones (the O-rings don't seem to like heat!).
I got mine off eBay. They don't cost much and will do the job. I won't mention any names
, but some racers use air compressor couplings with no problems. They're heavy and expensive, but they do the job if you do the o-rings on your proper one
.
Superlite you wouldn't have a brand name and part # for this would you? Looked everywhere on ebay and did a google search - only industrial items come up under dry break
Re: NC30 Petrol Tap Arrangement HELP!
Posted: Thu Oct 30, 2008 4:07 am
by RVFJE
Don't worry about my previous request - I found the plastic ones and can buy extra O Rings with them as that seems to be a problem.
Re: NC30 Petrol Tap Arrangement HELP!
Posted: Thu Oct 30, 2008 4:51 am
by Cammo
CRC makes them.
Re: NC30 Petrol Tap Arrangement HELP!
Posted: Thu Oct 30, 2008 5:46 am
by RVFJE
Thanks guys. Found them on Motion Pro site and cheap enough too.