clueless 2,898 #1 Posted September 29, 2018 I've got a Kohler 18hp on another brand, that started hunting , ran great with the choke out about a quarter. I put a new carb that I had on it and started it a ran it for about 30 minutes, ran great. Yesterday after driving it about a minute it started hunting again, choke out a little runs great, I've reset the governor and that didn't help. My question is if it's a governor problem wouldn't it still hunt with the choke closed a little? Share this post Link to post Share on other sites
prondzy 3,867 #2 Posted September 29, 2018 Fuel pump? 1 Share this post Link to post Share on other sites
Jerry77 1,218 #3 Posted September 29, 2018 17 minutes ago, prondzy said: Fuel pump? That would be my guess too.... Share this post Link to post Share on other sites
Mows4three 825 #4 Posted September 30, 2018 Folks: I hope this isn't interpreted as hijacking the thread (Mods: feel free to let me know). There's a mower in my shed that does something very similar. Just picked up another brand of garden tractor that that hunts when cold. It has a 18 HP Briggs opposed twin engine. I'm told it's been doing this for 10-12 years. After ten minutes of running the engine, playing with the choke, and a full warm up, it goes away. The carb has never been touched. Not being a master small engine mechanic, my guess is that it could potentially be an issue similar to that which "clueless" may be experiencing. Could some of you more experienced small engine guys chime in and tell us in order of probability, what could be the cause for an engine hunting. Sure appreciate your input. Thanks! Dave Share this post Link to post Share on other sites
clueless 2,898 #5 Posted September 30, 2018 18 hours ago, Jerry77 said: That would be my guess too.... Carb and fuel pump are new. So with the choke closed a little and it running fine, it may be a fuel delivery problem and not a governor problem? I'm just trying to eliminate things that may not be the problem. Share this post Link to post Share on other sites
kasey54 304 #6 Posted September 30, 2018 A shot in the dark here. I've had 2 briggs do this and felt the slop in linkage was the issue. I fixed both by putting a very weak spring between the govenor arm, and the throttle arm on the carb. Just enough to hold the slack . Good luck! Share this post Link to post Share on other sites
wallfish 15,919 #7 Posted September 30, 2018 20 minutes ago, clueless said: So with the choke closed a little and it running fine, it may be a fuel delivery problem and not a governor problem? Exactly. If it runs well when the choke is adjusted then you are effectively matching the air intake volume with the amount of fuel volume. Too much air is being pulled in when the choke is completely open. Carb adjustment? Air leak around throttle shaft or mounting gasket? With engine running spray some carb cleaner directly to the area at the throttle shaft, then directly on the gasket. If rpm changes at all then it is sucking it in and you have identified where the air is leaking in. Float setting? Dirty carb? clogged or weak fuel delivery from tank to carb. (fuel pump, clogged cap vent, clogged filter, clogged fuel line, ect. ????) 3 Share this post Link to post Share on other sites
clueless 2,898 #8 Posted September 30, 2018 26 minutes ago, wallfish said: Exactly. If it runs well when the choke is adjusted then you are effectively matching the air intake volume with the amount of fuel volume. Too much air is being pulled in when the choke is completely open. Carb adjustment? Air leak around throttle shaft or mounting gasket? With engine running spray some carb cleaner directly to the area at the throttle shaft, then directly on the gasket. If rpm changes at all then it is sucking it in and you have identified where the air is leaking in. Float setting? Dirty carb? clogged or weak fuel delivery from tank to carb. (fuel pump, clogged cap vent, clogged filter, clogged fuel line, ect. ????) Thank you sir. The carb, fuel pump, gaskets, filter and lines are all new with less than 1 hr on them. As I said it's been doing this for the last couple of years, it doesn't get used a lot, just been running with the choke out a little till I got around to replacing everything. Just wanted to make sure that it's a air/fuel problem and not a governor problem. Share this post Link to post Share on other sites