This engine is in a 1961 bolens ride a matic. It idles great and will take slow appliction of throttle to wot. But, nail it from idle its like you hit the killswitch. Even at part throttle when mower deck is engauged, the demand for power from the gov. will kill it. The carb has been totally disassembled, even shafts and nozzle soaked in carb kleener and new kit. Like I said, idle slow accell great, smooth, nail it and it shuts off. Bringing the throttle back to idle the engine will start again. New points too. Throttle shaft is a little sloppy. Spark seems ok, not a huge spark small and blue. Ideas please.
Kohler K161 Won't Take Hard Throttle
Posted November 06, 2013 - 09:46 PM
Posted November 06, 2013 - 10:31 PM
This must have adjustable jets. If so, open the idle and main jets 1/4 turn ie: counterclockwise.
Posted November 06, 2013 - 10:43 PM
Posted November 06, 2013 - 10:45 PM
I usually start of with 1 1/2 to 2 turn on my adjustment screws and then when it is running I'll adjust them. High speed first then the idle. Like ol'SB said it sounds like you need to adjust jet for more gas. How much slop in in the throttle shaft? You could be sucking to much air. I just had to replace one on a B&S 12 HP I got. The PO had cleaned the carburetor but it needed to be rebuilt.
- Trav1s said thank you
Posted November 06, 2013 - 11:09 PM
The high and low speed jets are adjusted correctly. They respond to adjustment perfectly. It will idle and run at any throttle position and cut grass without a miss. But give it quick throttle nothing (off) quickly back to idle position and it will fire and idle fine. Yes it sounds lean problem but its not jetting.
Posted November 08, 2013 - 06:42 PM
I think I have it. Too weak spark. 3rd new plug and tight gap on points much better. Still may have to pull flywheel to clean up mag and pickups. The throttle shaft is sloppy but does not have as much effect on jetting as you think.
Posted November 08, 2013 - 10:47 PM
Well, let us know how it works out.
Posted November 09, 2013 - 11:01 PM
A quick check for a common problem - make sure the resistance between the high-tension lead and ground is about 7K ohms (need to confirm this number). A common problem is that they will partially short out. That will cause a weak spark.
Posted November 13, 2013 - 11:57 PM
Thanks for the info, I will check that out. Even with it now below 0 (32 for you sobs) the tractor has fired right up, with electric start of course. With a little choke on and off it runs then takes quick throttle jabs no hesitation. I will still check resistance to eliminate that as a potential problem. Btw sob is south of the border.