KenH 0 #1 Posted April 27, 2018 I have a 520H that I couldn't get to stay running because the carburetor would flood. I removed the carb and cleaned it - soaking it in solvent overnight and then cleaning with carb cleaner and compressed air. I reinstalled the carb, changed the fuel filter and checked operation of the fuel pump - all seems good and there's flow of fuel to the carb, but it's not making it's way up through the needle valve and into the bowl. With all that I've done, I'm thinking it's an easy fix, but am coming to the experts here for advice. TIA. Share this post Link to post Share on other sites
lynnmor 6,764 #2 Posted April 27, 2018 If it floods, you are getting fuel. Then you say it isn't getting fuel. Replace at least the last section of fuel line if that wasn't included in the test. Did you completely disassemble the carburetor and properly clean all parts? Is the float stuck? 1 Share this post Link to post Share on other sites
GREYGHOST 65 #3 Posted April 28, 2018 (edited) The float and needle & seat would be worth taking a second look. Your original problem of flooding sounds like a float issue (stuck open). I'm sure that you cleaned all of the passage ways? PS. WELCOME Edited April 28, 2018 by GREYGHOST 1 Share this post Link to post Share on other sites
KenH 0 #4 Posted April 28, 2018 Thanks. With the carb installed, I removed the the needle and float. Gas travels up the passage way and into the bowl when I turn the key. However, when I reassemble everything, it doesn't seem to work. Could the fuel pump need maintenance to improve the flow? Maybe I should just buy a new carburetor. It's a Nikki 6100. Are those still available, and if not is there a preferred replacement? Share this post Link to post Share on other sites
lynnmor 6,764 #5 Posted April 28, 2018 There are aftermarket fuel pumps available on a popular auction site, but you are getting fuel. If you can find a new carburetor, simply get a home equity loan and buy it. Rebuild kits are available on that same auction site, just don’t use the manifold gaskets, get OEM. Nearly all carburetors only need cleaning and adjustment, and replacement is not necessary. Share this post Link to post Share on other sites
WVHillbilly520H 10,369 #6 Posted April 28, 2018 Yes to the above bit for the '96 year and newer if not '95 has "accelerator pump" carbs which are pricey as well as the repair/rebuild parts as I used the O.E. Onan parts to rebuild the carb on my anniversary 520 but some people like finding the pre-accelerator pump style carbs for a suitable replacement @boomers_influence or @onanparts.com should be able to help you out here if you wish to that route or for O.E parts, and I do buy/use the cheaper aftermarket fuel pumps without issue so far, Jeff. Share this post Link to post Share on other sites
GREYGHOST 65 #7 Posted April 29, 2018 18 hours ago, KenH said: Thanks. With the carb installed, I removed the the needle and float. Gas travels up the passage way and into the bowl when I turn the key. However, when I reassemble everything, it doesn't seem to work. Could the fuel pump need maintenance to improve the flow? Maybe I should just buy a new carburetor. It's a Nikki 6100. Are those still available, and if not is there a preferred replacement? Ken, When your cranking the engine with the Fuel Line Disconnected. Are you getting Good Fuel Flow or is it kinda weak and spurting? It could be a weak diaphragm but that doesn't relate to your Original Flooding issue. Are you sure you have your float level set correctly? Also remove your jet and make sure its clean and open. A piece of 0.020" of safety wire will or should pass through it. Share this post Link to post Share on other sites
lynnmor 6,764 #8 Posted April 29, 2018 1 hour ago, GREYGHOST said: Also remove your jet and make sure its clean and open. A piece of 0.020" of safety wire will or should pass through it. I would caution against using wire to clean jets, that can scratch the surface and alter the amount of fuel flow. I use a bristle from a paint brush. 1 Share this post Link to post Share on other sites
KenH 0 #9 Posted May 3, 2018 I retested the flow and it looks pretty weak/spurting. I'm not sure how to set the float level, so any help there would be appreciated. Also, aside fro the filter between the pump and the carb, is there any other filter that should be cleaned/replaced? Thanks. Share this post Link to post Share on other sites
lynnmor 6,764 #10 Posted May 4, 2018 One source of a manual: Manual Vacuum fuel pumps do work in spurts. There is a screen in the tank outlet. Share this post Link to post Share on other sites
ericj 1,576 #11 Posted May 13, 2018 double check your needle and float assembly, i try to remember to check the float assembly movement by pushing and actuating the float up and down. sometimes something jams up and you may have a stuck needle not letting gas in eric j Share this post Link to post Share on other sites
bo dawg 476 #12 Posted May 15, 2018 Can the gasket for the top of carb be bought with out having to buy the whole kit? Sorry about jumping in on the post Share this post Link to post Share on other sites
