I'v been using Quantum fuel pump kits lately to re build customers pumps great they come as a kit so I no longer had to source the filters and seals separately win win or at least until I got a phone call from a team that nearly had a pit fire. Irate guy says he pulled fuel line to remove tank and petrol came running out the tank outlet over the scolding hot bike I briefly flaunted the idea I had assembled it wrong or badly and asked if there had been a drop in performance since he had it fitted " Fuck No" came the reply, so I guessed poor seals or bad assembly wasn't the issue. I had the assembly exchanged for another unit. I stripped it down found no fault reassembled no fault, on a bike pulled line and fuel ran out continuously . I striped down again re-fitted with a OE pump same housing and seals repeated test, no fuel running out So I bench tested the Quantum pump itself with a simple low pressure gravity feed, to my horror the motor allowed fuel to run out just under the weight of fuel in the tank. FFS that means not only when you disconnect the fuel line but should you have an accident and any part of the fuel system gets damaged your going to have fuel running out. I tested all manner of after market pumps including chinese ones that are 1/5 the price, I tried all the OE ones and all have a check valve preventing this, these bikes and most modern bikes do not have fuel taps anymore as the submersible pumps are supposed to be also one way valves. I called in the 4 pumps I had done with Quantum and all four are the same as in allow fuel to run out. As pictured the motor kits for G3-4 & 5 are the same, and the G2 kit I had was the same. The serial numbers of the motors are clearly in the picture, I replaced with MSR pumps that I was using before and all is good. I have been refunded by Quantum but they took no responsibility and denied there is an issue. Guys do not use these pumps and spread the word somebody somewhere could get seriously hurt with these.