Kyler 1 Posted January 4, 2021 Hey guys I have a Honda 500 and it was running good but it would stall every now and again so I took the carb out and cleaned it. I didn’t clean it very good because I ran out of carb clean. I’m going to grab carb clean tomorrow and clean it better. I took the air screw out not realizing that that is what it was and put the carb back together and now it sputters at about half throttle. I tried backing the screw off and screwing it in and it didn’t seem to make a difference in idle or anything. It is idling a little rough too. Any ideas. Thanks in advance Share this post Link to post Share on other sites
Fishfiles 20,148 Posted January 4, 2021 Welcome to the forums , Kyle ---- First thought , maybe you did clean the carb good enough or it got recontaminated right off the bat cause the tank is fowled and you recontaminated the carb , or maybe the diaphragm has a crack or you damaged or pinched the diaphragm on reassembly ---some don't believe in soaking a carb but I do , in a gallon can of Berryman Carb cleaner , then blow it out with compressed air 3 Share this post Link to post Share on other sites
Kyler 1 Posted January 4, 2021 So should I clean it really good and check the diaphragm, throw it back in and maybe put an inline fuel filter in there? It just doesn’t make a whole lot of sense because it was running pretty good before I took it apart and screwed with the air screw Share this post Link to post Share on other sites
retro 4,074 Posted January 4, 2021 Hi Kyler, welcome to ATV Honda! Set the pilot screw 2 5/8 turns out from lightly seated initially, then warm up the motor. While the warm motor is idling, slowly turn the pilot screw in and out until you find where the motor idles the best, or idles at the fastest RPMs. Then slowly turn the pilot screw in until the idle just begins to slow down & weaken and stop turning the screw. Then turn the pilot screw out one full turn from that point and you're done adjusting the idle mixture. Attached is the adjustment procedure from the 2001-2003 Foreman Rubicon 500 service manual. You do not need a tachometer to adjust the idle mixture, your hearing is accurate enough. 🙂 If the motor is stumbling near half throttle the slide piston diaphragm may be out of place as Fishfiles mentioned. I am assuming that you took the top cover off of it....? You gotta use your finger to hold the slide piston up while putting the top cover on. Attached is the procedure for putting that together as well. Let us know how it goes. 1 Share this post Link to post Share on other sites
Kyler 1 Posted January 4, 2021 Ok thanks a bunch I didn’t know that you had to hold that thing up when you put it on Share this post Link to post Share on other sites
87Iroc 344 Posted January 4, 2021 On the fuel tank deal. On mine. I ran a filter for a while while i was diagnosing. Kept getting a stuck float due to debris running out of the tank. Its really tough to fit them in due to the design of the carbs and system. After getting scolded by a senior member here. I flushed the tank good and put it back together w/o the filter. Never had a problem after that. How I knew I had a problem was fuel would randomly run out on the floor after I'd shut it off. I have heard that a piece of debris can easily clog a main jet, though. Share this post Link to post Share on other sites
Kyler 1 Posted January 5, 2021 So cleaning didn’t help anything. I farted around with the screw some more to and that didn’t do anything either. Any other ideas? Share this post Link to post Share on other sites
Kyler 1 Posted January 5, 2021 When I’m going down the field and pin it. It seems like it loses fuel for a second and then gets going again. And I don’t know why it’s doing it because it wasn’t doing it before Share this post Link to post Share on other sites
retro 4,074 Posted January 5, 2021 I dunno if its a lean condition ya got or a rich one.... can you pull the spark plug out and take a photo of the combustion end of it for us, so we can see what the mixture condition is? Share this post Link to post Share on other sites
Fishfiles 20,148 Posted January 5, 2021 5 hours ago, Kyler said: When I’m going down the field and pin it. It seems like it loses fuel for a second and then gets going again. And I don’t know why it’s doing it because it wasn’t doing it before Could be the screen in the tank is dirty and slowing flow , or maybe the petcock is clogged up ------ when you cleaned that carb , did you take it totally apart and clean every hole with compressed air ? ----- check the boot connection between carb and head for a leak with some starting fluid , while running spray some around the boot , if the idle jumps up you have a leak ----- did you ever do a compression test on you engine 1 Share this post Link to post Share on other sites
Kyler 1 Posted January 6, 2021 I’m getting a new spark plug tomorrow. And I’ll take it for a rip and show you guys the spark plug 1 Share this post Link to post Share on other sites