TC10284 109 #1 Posted September 13, 2019 (edited) 3114K804 model 414-8 with M14S engine. I've been having a lot of trouble with this one sputtering and dying at half throttle or higher. It will idle fine. And it will open up to full throttle just perfectly the first time that day, even with deck engaged, when sitting still BEFORE I back it out to test it. But as soon as I back it out and open it up all the way, it will begin sputtering bad and eventually die out unless I put it back to idle. When this starts, you can't raise the throttle past half way or it will die. Choking it about 85% gets it going again at full throttle however. I've put a fuel filter in the fuel line near the bottom of the engine. I've drained all the gas and put in fresh, in case it was bad or had any water in it. The fuel grommet tore and I replaced that. Also made sure the fuel shut off was not blocked by blowing through it both ways. No issues with that part. So at this point I'm assuming there's trash or some kind of blockage in the carb. Or maybe a faulty float? Edited September 13, 2019 by TC10284 Share this post Link to post Share on other sites
troutbum70 857 #2 Posted September 13, 2019 I would think carb or fuel pump not keeping up, I am sure more will chime in with better advice. Could be timing maybe. Share this post Link to post Share on other sites
Ed Kennell 35,773 #3 Posted September 13, 2019 When it requires choking to keep it running at WOT, that signals a lack of fuel or too much air leaking in around the throttle shaft or the carb mounting flange. With the engine running , spray starting fluid around the shaft and flange. If the engine speeds up, air is leaking in. 1 Share this post Link to post Share on other sites
TC10284 109 #4 Posted September 13, 2019 20 minutes ago, Ed Kennell said: When it requires choking to keep it running at WOT, that signals a lack of fuel or too much air leaking in around the throttle shaft or the carb mounting flange. With the engine running , spray starting fluid around the shaft and flange. If the engine speeds up, air is leaking in. Will try this. What I don't get yet is why it runs great at WOT at first until you start moving, typically downhill, and then it decides to crap out. Share this post Link to post Share on other sites
lynnmor 6,779 #5 Posted September 13, 2019 Maybe the carburetor float level is too high or the float valve is bad. Share this post Link to post Share on other sites
ebinmaine 63,143 #6 Posted September 13, 2019 Are you using fuel with ethanol? When we the last time the carb was disassembled and cleaned? How old are the fuel lines? Share this post Link to post Share on other sites
gwest_ca-(File Mod) 10,499 #7 Posted September 13, 2019 You don't think it is ignition related? Runs the same with pto on or off? The seat switch controls the ignition when the pto is engaged. Operator leaves seat the switch grounds the magneto ignition shutting it off. They can be sensitive to weight in the seat. Garry Share this post Link to post Share on other sites
Ed Kennell 35,773 #8 Posted September 13, 2019 9 hours ago, TC10284 said: Will try this. What I don't get yet is why it runs great at WOT at first until you start moving, typically downhill, and then it decides to crap out. Like Lynn said, This new information indicates a carb float problem . Share this post Link to post Share on other sites
TC10284 109 #9 Posted September 13, 2019 37 minutes ago, Ed Kennell said: Like Lynn said, This new information indicates a carb float problem . I'll get it checked/replaced and cleaned and we'll see if that resolves. Share this post Link to post Share on other sites
TC10284 109 #10 Posted September 13, 2019 (edited) Update: Took carb off and took it apart. First thing I found was a missing screw on the throttle side butterfly. Replaced that with a spare laptop screw that fit it perfectly. Second thing I found was the main needle was flaking off it's "paint". Scrubbed all that off, put it back together and it runs a lot better. It occasionally "misses" but nothing impactful. Float was fine. Submerged for a while, no water in it. Did not sink at all. Edited September 13, 2019 by TC10284 2 1 Share this post Link to post Share on other sites
ebinmaine 63,143 #11 Posted September 13, 2019 Well done!! 1 Share this post Link to post Share on other sites
TC10284 109 #12 Posted September 13, 2019 Also wanted to add that I made sure all passages were clear. 1 Share this post Link to post Share on other sites
ebinmaine 63,143 #13 Posted September 13, 2019 2 minutes ago, TC10284 said: Also wanted to add that I made sure all passages were clear. Nice... Certainly wouldn't hurt anything to mix some Seafoam in with your gasoline for a little while Share this post Link to post Share on other sites
953 nut 51,717 #14 Posted September 14, 2019 2 hours ago, TC10284 said: I found was a missing screw on the throttle side butterfly. Replaced that with a spare laptop screw that fit it perfectly. Hope you used some Loctite Red on that screw! If not you should do it. Share this post Link to post Share on other sites
