Fuel pump problems

[mattiec321]

Hi guys.

After a run out at Snetterton yesterday a pumping issue almost ruined my day.

The pump is running constantly, its not stopping after priming so it was fine ticking over and on the straights but when off throttle and into corners it would flood the engine, dangerous during an open pit day with racers buzzing you.

Eventually I disconnected and bypassed it, giving me again a perfect running bike.

My question is what has caused the pump to run all the time? The points in the pump were replaced last may and it has had very little use since then.

Thanks in advance

[willandrip]

Most fuel pumps are pressure regulated internally.
Once pressure is reached an internal mechanism cuts off electrical supply.
If a pump has a pressure rating in the specs. that is an indication that it is internally regulated when purchasing a generic pump.

Yours MAY be of different construction or simply faulty...like Basil.

Pump should not run continuous....was it probably a cheap replacement ?
No...you stated points replacement....Its had its lifespan extended already !

Mind...correctly set and in good order float needle valves will prevent fuel flow at a much higher pressure than designed for....something may be amiss there unless all cylinders are affected.

[mattiec321]

Thanks for that I kinda get what your on about. Basically although I've changed the points my pump could have been replaced at some point in is life for a cheapy and now is toast.... Ace. Maybe for the rest of the trackday season I'll leave it gravity fed.

[willandrip]

No...I think if you put points in it will be a good pump , probably Factory fitment......just old and tired now.
Cheap generic pumps aren't rebuildable....have no spares backup.

[Gimly56]

I've had 4 x CBR400s and ALL of them have had fuel pump failures at any given time. Fuel pumps and reg/rectifiers are common as muck issues for these bikes........I recommend you buy a decent replacement fuel pump.

[JZH]

Assuming these are standard Honda (Mitsubishi) electric fuel pumps (looks like, from the pics in the NC29 Haynes manual), points failure is very common. I've converted my RC36 to use a Facet solid state pump, but it is not an ideal solution.

However, there is another option. A Dutch guy on the ADV Rider forum called Dr_Bean makes a €42 optical "points" replacement kit for the KTM 950. (Stay with me on this...) It turns out, KTM also uses essentially the same pump, as do the 650cc and 750cc Honda Africa Twins. Installation instructions are here: http://www.lc8.nl/download/Fuelpumpprin ... ual_V3.pdf

I can't guarantee that this kit will work, but I went ahead and bought one for my VFR750 and have installed it into one of my failed OEM fuel pumps. I still need to re-do the fuel lines back to the OEM configuration, so I have yet to test the kit, but it seems to fit like it was made for this pump.

Ciao,