As title suggest, I've got a 6.5HP briggs that's running like garbage. Bought it used so I don't know the history, but it doesn't look to have many hours, as the gearcase busted a chain soon after purchase as per the previous owner. Gearcase is now rebuilt and working great, but the engine is causing me grief.
Engine runs super rough, black smoke (thick black deposits at muffler too, may not be a new issue?) and kind of sputtering. Will not build RPMs when at high throttle (throttle seems to be adjust correctly, and if you watch the carb the throttle is wide open, not surging etc). I took it apart to attempt to clean the carb, everything looked to be pretty decent, and all jets seemed open when sprayed with cleaner. (Bottom main jet, two jets in the bottom middle, and 3 jet/brass things on the front inlet side of the carb. I didn't go too crazy with the carb so it may still be a carb problem, unsure. Choke circuit was working fine. I drained out the old fuel (fuel flow seemed fine, filled up a 1L jug fairly fast, with a nice steady flow) and put in fresh stuff. Air cleaner looks almost new, but I also tried running it with no air cleaner to no avail. The one thing I did notice was that when I shut the fuel flow off it seemed to run better until it died, not sure if that is indicative of anything. This makes me think it might still be a fuel issue?
Video of it running can be seen here.
In the video I start it at full throttle, let it idle for a few seconds to show how it's running, then shut off the fuel selector to show how that changes how it's running.
Is there some part of the carb that I should be taking extra care to clean? Do I need to go deeper into the engine? Kind of out of ideas at the moment as to what the problem may be, and am open to suggestions! Thanks!
Edit: Just remembered something strange, when I took apart the carb there was a little brass plug looking thing sitting in the bowl. It seemed like it fit in the left side hole in the intake side of the carb (and looked similar to the two brass plugs in the two holes on the right hand side of the intake) but I'm just realizing this probably isn't where it was supposed to go! Pic of plug here
Engine runs super rough, black smoke (thick black deposits at muffler too, may not be a new issue?) and kind of sputtering. Will not build RPMs when at high throttle (throttle seems to be adjust correctly, and if you watch the carb the throttle is wide open, not surging etc). I took it apart to attempt to clean the carb, everything looked to be pretty decent, and all jets seemed open when sprayed with cleaner. (Bottom main jet, two jets in the bottom middle, and 3 jet/brass things on the front inlet side of the carb. I didn't go too crazy with the carb so it may still be a carb problem, unsure. Choke circuit was working fine. I drained out the old fuel (fuel flow seemed fine, filled up a 1L jug fairly fast, with a nice steady flow) and put in fresh stuff. Air cleaner looks almost new, but I also tried running it with no air cleaner to no avail. The one thing I did notice was that when I shut the fuel flow off it seemed to run better until it died, not sure if that is indicative of anything. This makes me think it might still be a fuel issue?
Video of it running can be seen here.
In the video I start it at full throttle, let it idle for a few seconds to show how it's running, then shut off the fuel selector to show how that changes how it's running.
Is there some part of the carb that I should be taking extra care to clean? Do I need to go deeper into the engine? Kind of out of ideas at the moment as to what the problem may be, and am open to suggestions! Thanks!
Edit: Just remembered something strange, when I took apart the carb there was a little brass plug looking thing sitting in the bowl. It seemed like it fit in the left side hole in the intake side of the carb (and looked similar to the two brass plugs in the two holes on the right hand side of the intake) but I'm just realizing this probably isn't where it was supposed to go! Pic of plug here
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