I've got a 4 year old Lawnboy push mower with a Kohler XT-6 in it. First few years ran great, last couple years it starts misfiring once it's warmed up. Sometimes a little worse, sometimes not as bad.
I drain the fuel and change the oil, put oil in the cylinder and all that stuff every fall. I've changed the air filter and spark plugs, sprayed some carb cleaner in the carb with the bowl and air filter assembly off, run some fuel system cleaner through it, pulled out the inline fuel filter that sits in the line near the tank and sprayed it with cleaner... let's see what else... oh, I checked the auto choke and it opens properly when warmed up...
Basically, is there anything else anyone knows about these engines before I pull off the carb completely and overhaul it? I don't want to do that because, well, I'm lazy and I have a crap-ton of other more important things to do. It's driving me crazy though, so I'm hoping that if I wish really hard it will be something else a little easier to fix.
It starts 1st pull every time, runs smooth and quiet, powers through my usually slightly overgrown lawn just fine. All until it gets warm then - mmmmmmmmm-putt-uhmmmmmmmmmmm-puttputt-uhmmmmmmmmmmmm. Kinda like that :biggrin: It still mows, but I like my machines to work like new.
Anyone?
PS - I hate signing up to a forum just to ask a question, so once I figure it out I'll try to post my solution in the hopes of saving someone else from wasting time hoping that it isn't their carburetor causing the problem.
Thanks for the reply. I did get the service manual. That was what led me to check the auto choke warm up spring function. I was super excited that that might be broken, but it wasn't. The symptoms do track with the action of that spring though. Once the choke plate gets almost open or fully open is when it starts missing.
I guess that pretty much guarantees that it's a fuel issue huh?
#4
Fish
Not totally. I am not familiar with this engine, so can you put up some model spec numbers? Also run it until it starts acting up, then remove the air filter while it is still running, see what changes....
#5
EngineMan
Do a compression test cold and then hot. should be around 160psi
