nekovt 0 #1 Posted May 30, 2012 Hello! I just rebuilt (and soaked) the carburator in a 520-8 which had surging idle symdrome. There was a lot of gunk which came out no problem. Now it's acting like it's flooding out even though I've adjusted the float several times, even adjusted it a bit down. I can get it to run smoothly for quite a while if I shut off the gas at the tank as soon as it starts to sputter. If I leave the gas tank valve open, then it floods out, smokes and quits. I replaced the gas lines and filter. (thought it was 5/8 inch, put 5/8 in up until the fuel pump, then 1/4). The float looks good I did not use compressed air because I think I heard there's some screens in the carb somewhere. I took the top of the carb and see that the float has risen and allowed the pin to go in. The seal looks ok. The only think I can think of is the black cardboard like thing that goes in the carb has a little bit of "stuff" on it which I scrapped off lightly. I'm not so sure that's the problem though. Has anyone run in to this? Thanks! BRad Share this post Link to post Share on other sites
1maidenfan 201 #2 Posted May 30, 2012 I went through some thing like that with my onan 16 hp on my D 160. Drove me nuckn futs trying to figure out the problem, thing would run for a few then flood out. Rebuilt carb with new parts, done all the valves, re set timing, changed fuel filter and lines. Come to find out when I rebuilt the carb I replaced the old float with a new metal float. When I checked it, it had fluid (gas) inside one of the floats which made it heavy enough that it would not float up to shut off the fuel. Might be some thing to look into, pull it off and shake it, if you hear fluid in it, it is bad and the reason your floading. Worth a shot. Share this post Link to post Share on other sites
mattd860 162 #3 Posted May 30, 2012 I had the same problem but it ended up being that the intake valves were badly out of adjustment basically preventing the intake valves from fully closing and sealing. This will force combustion gases back through the carb which will also push fuel backwards through the carb and flood the air filter. I could actually see fuel spraying out of the carb inlet. Check into this before tearing apart the carb. Share this post Link to post Share on other sites
nekovt 0 #4 Posted May 30, 2012 Thanks! I'll check both! What's funny is that I was able to get it to run for quite a while maybe 45 min the other day, I even mowed with it. I'll check the carb to! Share this post Link to post Share on other sites
mattd860 162 #5 Posted May 30, 2012 Thanks! I'll check both! What's funny is that I was able to get it to run for quite a while maybe 45 min the other day, I even mowed with it. I'll check the carb to! This is EXACTLY what happened to mine. Sometimes it would start up and then immediately flood. Sometimes it would run for a long time and then flood right out. You could remove the air cleaner/filter and check for fuel misting out of the carb or see if the inside of the air cleaner is wet. Also, if the motor floods due to badly adjusted intake valves, removing the air filter will prevent it from flooding. Share this post Link to post Share on other sites
TheReDStAnG 4 #6 Posted May 31, 2012 If you do happen to take the top of the carb apart again, I would remove the fuel line from the fuel pump to the carb and put a little air pressure (less than 4psi) to verify to carb float and seat are working properly. A lot of air bubbles would indicate that they aren't sealing properly. The fuel pump will constantly pump fuel (engine running) if there isn't something to stop it (float and seat). Share this post Link to post Share on other sites
