poobarge

Well done mate, good find! Also there is plastic round disc cylinder which sits on top of that o-ring that moves up and down in the top housing. If you've replaced the filter and you have a flat spots when hard on the throttle you probably are missing this plastic round disc cylinder and may be sitting in the old filter or fell out during installation. If your having long crank time but no flat spots this disc cylinder is probably stuck in the top housing. Put it on top of the o-ring in the filter housing and assemble the top housing onto it. I to had issues but after checking both of these rectifing and reinstalling i have had no issues since. I presume that the disc cylinder acts as check valve to stop fuel returning to the tank and also the seal from the pump to the top housing. Hope this helps......