eBay nc30/35 fuel tap mod???

[juggernaut]

eBay 130816439918


Any experience of these or feedback for me before I bid?
Thanks
Luke

[thunderace]

For a road bike? Why? Just fix your tap properly if it's faulty.

I'd have a serious issue with his pricing, there's less than £1 worth of alu and stainless in that lot. Machining on his blanking plate is minimal, purely creating the rebate for the O-Ring and rounding the corners.

And his third point is a load of bollocks anyway.

[juggernaut]

I should of pointed out my tap on he rvf is leaking fuel when it's sat, bought his mod my be an upgrade that fixes my problem as well?

[thunderace]

Problem with the mod is that if you forget to turn the tap off you end up with a flooded engine.

[speedy231278]

The HRC mod is intended to improve fuel flow at the expense of removing the feature that stops a tap that is left on from filling the engine with petrol should one of more float valves stick open. You do not need to buy any bits to do the HRC mod as it is done using parts in the original tap (and some are removed). I've run the mod for almost a decade on the road without issue. That is not to say that one day I might find that I've been an arse, and forgotten to turn the tap off and the engine is flooded with petrol. On the rare occasion I forget to turn the tap off and the bike has sat, I remove the oil filler to make sure the cases aren't filled up.

If your tap is leaking, and I presume you mean leaking out of the tap rather than the tap not stopping fuel from flowing to the carbs, then the chances are it needs fixing properly rather than modifying as one of the seals is shot, or there is something else wrong. The kit on eBay might fix that, there again, it might not.

16953-MBZ-B51 (supercedes 16953-MV9-000) is the Honda OEM fixing kit. OK, it's £33 or thereabouts, but you get basically the whole vacuum side of the tap, new screws, spring, etc. You can get these from Honda, and Rick Oliver does them too. He also does a kit with just the seals and spring (pattern) for £20, which frankly renders the eBay kit redundant. Pic 'borrowed' from CMSNL.com



The world's your lobster. You might find the HRC mod fixes the leak, but there's no guarantee, and you have to be disciplined enough to remember to turn the fuel off every time you stop the bike. If you're buying bits to fix it, you might as well do it properly.

[juggernaut]

Its the tap that is leaking in to the carbs not out of the tap on to the floor

Ok, thanks once I get paid ill get the kit off RO along with some other stuff.

Thanks for the input, pretty much made my mind up now guys


Luke

[speedy231278]

TBH, I'm not sure what needs to fail to cause a tap to flow when it's turned off. Must surely mean the diaphragm isn't shutting, but that's a back-up to the actual tap being shut. I'd be interested out of curiosity to hear what you find. In my experience, if anything goes sick with the diaphragm, it shuts rather than opens, but clearly that's not always the case. I'd be more inclined to blame something inside the tap rather than the vacuum assembly for the source of the leak, then the diaphragm for not correcting the issue. But that's my lack of experience of this issue. I just had the experience of running out of fuel on a full tank!

[juggernaut]

I thought it may if been the diaphragm but I've not had it apart , ill get an order in with RO instead of the eBay mod thank you :0)

[thunderace]

TBH, I'm not sure what needs to fail to cause a tap to flow when it's turned off. Must surely mean the diaphragm isn't shutting, but that's a back-up to the actual tap being shut. I'd be interested out of curiosity to hear what you find. In my experience, if anything goes sick with the diaphragm, it shuts rather than opens, but clearly that's not always the case. I'd be more inclined to blame something inside the tap rather than the vacuum assembly for the source of the leak, then the diaphragm for not correcting the issue. But that's my lack of experience of this issue. I just had the experience of running out of fuel on a full tank!

From experience, it's usually the membrane that fails inside the tap.

[pip]

Reading this, I have fixed (bodged) several 'permanently on' Honda vavuum taps over the years.

Inside the end cap is a small steel plate pressed in that has a tiny hole in the middle, behind which is a thin rubber baffle - I believe this rubber swells/ deforms with age. Sometimes flipping it over works, if not I have just removed it & all works perfectly again

When this rubber baffle deforms it prevents atmospheric air back into the chamber when the engine is turned off & thus closing the tap.

Or you could buy the repair kit!

Pip