hotajax 223 #1 Posted October 24, 2023 If tractor is idling, and I go from idle to full speed with the throttle, and get a small puff of smoke, which screw do I adjust? The idle screw or the high speed screw? It also smells a bit rich while I'm cutting, so I probably need to lean that one out. Thanks 1 Share this post Link to post Share on other sites
ri702bill 8,341 #2 Posted October 24, 2023 Getting the "transition" from idle to main jets can be a challenge some times. On a fully up-to-temp engine - engine "off", refer to the Kohler manual - close to idle screw GENTLY, back it out the recommended number of turns. Do the same for the main. Start the engine - check the idle RPM. close the idle screw 1/8 turn at a time until the rpm drops, go back to where you were, noting the number of turns - do the same backing it out, rpm MAY rise - that is good - continue until it starts to fall. Go back to the highest idle rpm. Throttle up from idle. Did it go smoothly or stumble?? Do the high speed screw next - same procedure. You May have to richen the mix on the idle to "fix" a stumble. Short version - OK to go a bit rich on the idle circuit to get a good transition - you do no "Work" at that speed. Get the best rpm and throttle response at the high rpm work range - do NOT go lean!!! 3 Share this post Link to post Share on other sites
Wheelhorse#1 1,669 #3 Posted October 24, 2023 Also check to make sure the choke is adjusted properly.Sounds dumb but I a had a running rich issue and I somehow overlooked the choke/ butterfly slightly in closed position . Sometimes the small things can easily get over looked. 4 Share this post Link to post Share on other sites
hotajax 223 #4 Posted October 24, 2023 45 minutes ago, ri702bill said: Getting the "transition" from idle to main jets can be a challenge some times. On a fully up-to-temp engine - engine "off", refer to the Kohler manual - close to idle screw GENTLY, back it out the recommended number of turns. Do the same for the main. Start the engine - check the idle RPM. close the idle screw 1/8 turn at a time until the rpm drops, go back to where you were, noting the number of turns - do the same backing it out, rpm MAY rise - that is good - continue until it starts to fall. Go back to the highest idle rpm. Throttle up from idle. Did it go smoothly or stumble?? Do the high speed screw next - same procedure. You May have to richen the mix on the idle to "fix" a stumble. Short version - OK to go a bit rich on the idle circuit to get a good transition - you do no "Work" at that speed. Get the best rpm and throttle response at the high rpm work range - do NOT go lean!!! Thanks, Good write up. Where in RI are you? I spent ALL of my RI time in Newport. Avoiding the brig after a night out. 1 Share this post Link to post Share on other sites
ineedanother 1,369 #5 Posted October 24, 2023 40 minutes ago, Wheelhorse#1 said: Also check to make sure the choke is adjusted properly.Sounds dumb but I a had a running rich issue and I somehow overlooked the choke/ butterfly slightly in closed position . Sometimes the small things can easily get over looked. True. And you might want to give a good quality new spark plug a try as well before you're chasing the wrong issue. 2 Share this post Link to post Share on other sites
ri702bill 8,341 #6 Posted October 24, 2023 30 minutes ago, hotajax said: Where in RI are you? West Bay - the mainland. Actually, my town is the geographic center of RI. I avoid "Zooport" - too many ripoff restaurants and maroons. Team that up with beach traffic - not for me.... 1 Share this post Link to post Share on other sites
953 nut 55,323 #7 Posted October 24, 2023 Here is information from the Kohler manual.Rich is betern than lene. If the mixture is too lene an engine will overheat. 1 Share this post Link to post Share on other sites
hotajax 223 #8 Posted October 25, 2023 7 hours ago, ri702bill said: West Bay - the mainland. Actually, my town is the geographic center of RI. I avoid "Zooport" - too many ripoff restaurants and maroons. Team that up with beach traffic - not for me.... Gotta go where the Navy sends ya 2 Share this post Link to post Share on other sites
hotajax 223 #9 Posted October 29, 2023 Thanks for the tips on setting the carb. The diagram from @953 nut and @ri702bill was priceless. Richened up the low end, and it idles sweet. No more pops. Thanks again, gents. 1 Share this post Link to post Share on other sites
hotajax 223 #10 Posted October 29, 2023 Of course I don't think it hurts that my tractor is now running on non-ethanol gas. Share this post Link to post Share on other sites