1998 johnson 225. I cleaned all 6 carbs with new gaskets installed over winter. Boat runs up to 5700RPMS at WOT and idles in great at around 750rpms per my OMC tach. It will idle at the dock for 20 minutes no problem, and will idle forward when leaving the dock for a long time too.
When running the boat at 4000+ RPMS, when I back off to idle forward, it began sneezing last week. I used an unlit propane torch to isolate the sneeze to cylinder #5. I removed the carb and cleaned the brass idle passage again. Put back on, ran the boat again at idle forever at dock no problem. Ran at speed for a day and when coming home the boat sneezed at idle fwd twice in about 10 minutes. Stalled one of those times. If I bump the RPMS to 850/900 or so I never stall.
Any ideas? The sneeze is so intermittent I haven?t yet been able to use the propane trick to find the lean cylinder.
I am wondering if this is tied to the temp of the engine? Seems to only happen when warm?air leak? Also wondering if I should check #5 and #6 throttle plates for full closure but if this were a lync and sync issue wouldn?t it happen at all times / temps? Only other thought was maybe adjust that carb bleed screw, or remove carb and clean the throttle plate passages (I did not do that when cleaning the carbs)?
Last question ? I know the idle, mid and high speed jets are separate. With this intermittent an issue only at low idle, I?m in no danger of leaning out a cylinder at non-idle speeds if I occasionally run the boat while I address this, correct? Have a crew coming fishing tomorrow and don?t want to cancel.
When running the boat at 4000+ RPMS, when I back off to idle forward, it began sneezing last week. I used an unlit propane torch to isolate the sneeze to cylinder #5. I removed the carb and cleaned the brass idle passage again. Put back on, ran the boat again at idle forever at dock no problem. Ran at speed for a day and when coming home the boat sneezed at idle fwd twice in about 10 minutes. Stalled one of those times. If I bump the RPMS to 850/900 or so I never stall.
Any ideas? The sneeze is so intermittent I haven?t yet been able to use the propane trick to find the lean cylinder.
I am wondering if this is tied to the temp of the engine? Seems to only happen when warm?air leak? Also wondering if I should check #5 and #6 throttle plates for full closure but if this were a lync and sync issue wouldn?t it happen at all times / temps? Only other thought was maybe adjust that carb bleed screw, or remove carb and clean the throttle plate passages (I did not do that when cleaning the carbs)?
Last question ? I know the idle, mid and high speed jets are separate. With this intermittent an issue only at low idle, I?m in no danger of leaning out a cylinder at non-idle speeds if I occasionally run the boat while I address this, correct? Have a crew coming fishing tomorrow and don?t want to cancel.