bo dawg 518 #1 Posted January 22, 2010 Alright guy's, tell me something about these little plastic fuel pumps that mounts on the side of the engine cover. I believe it may have sucked some crap from the tank. I'm not getting fuel to the pump. I can blow through the hose and I am getting fuel out the tank with the hose off. Now from looking at the pump I assume its vacuum controled and probably pulls the fuel from the tank I can blow air into the inlet and feel air thru the outlet, so makes me wonder if it is really pluged at all. Could it be pluged in the vacuum side of it maybe? I blew a little air in it too. Doesn't appear to come apart so to look inside and check it out (without breaking). So whats the story with this system. I really don't know anything about it. Share this post Link to post Share on other sites
ezeastside 93 #2 Posted January 22, 2010 Hi Bo Dawg, I'm certainly not an expert with these but have ran into the situation with my 520. The fuel pump does use vacuum to pulse the diaphram in the pump to move the fuel up to the carb. I did actually buy a used on from e-bay when I was having trouble with it and after I installed it really didn't change my issues. There is supposed to be a type of check valve internally i believe with a ball and spring. The ones I have do come apart with 4 small phillip screws and can be cleaned but care needs to be taken when seperated as the spring wants to jump and be free. Good Luck Hope this helps Ed Share this post Link to post Share on other sites
Rollerman 290 #3 Posted January 22, 2010 Bo the last 520H I owned....the tank had pine needles in it. I can only guess the PO let it set outside by some pines & the fuel cap was pulled off for some reason....so I had lot's of issues finally getting the fuel system clean. Take your pump off & pull it apart for a cleaning. If crud gets in the pump & holds the reed valves open it will no longer pump fuel. They are a vacume type pump & real easy to work with just have a clean area to lay everything out. Put a fuel filter inline between the tank & pump if it doesn't have already. Share this post Link to post Share on other sites
bo dawg 518 #4 Posted January 23, 2010 I don't see how it comes apart to clean it. Theres no fasteners. I tryed prying on it a little but afraid I'll break it. Share this post Link to post Share on other sites
ezeastside 93 #5 Posted January 23, 2010 The one on my 520 and the spare that I have, both have 4 screws in the front corners. When removed will spit the sections. Maybe yours is an aftermarket or different style. Share this post Link to post Share on other sites
