Duff 206 #1 Posted September 19, 2009 Hi, guys, This will be a little long but I hope worthwhile.... So....about a week ago I had fuel problems and did a carb tear-down. Cleaned everything up very carefully, reassembled and the engine ran like a top. We've had good weather so after I washed the machine and deck from mowing I left it outside for a couple of days to get some fresh air and sunshine (yeah, I'm twisted). Went to put it away and it started, ran for about a minute, then gradually died. Restarted on the choke, but withered and died again in about 10 seconds, and that was it. Ran the same diagnostics as the first time - fuel filters, fuel lines fuel pump...all were clear and clean. Good spark, too. But no starting . Figuring something had migrated into the innards of the carb again, I took it apart a second time. As I took the float off the carb I realized the needle valve was stuck in the seated position, thus no fuel was coming into the bowl. OK. 20 year old machine - probably a worn out needle. No problem - rebuild kit! BUT....when I went to find a kit, I found it was NLA from Kohler, Jack's, Pat's, Partstree. Oh crap! Then I found an outfit called SuperX Power Center in Milaca, MN. http://www.superxpower.com/ They've still got 'em, and I ordered two since I have another M12 to work on. So there's the first hopefully helpful point. Second, something possessed me to tear down the carb on my other M12 just to see if maybe I had reinstalled something wrong or was overlooking something. That turned out to be a blessing. The experts here will probably get a chuckle out of what follows, but maybe it'll help another newbie somewhere down the road: What I never saw and apparently lost without knowing it was very tiny (and by tiny I mean the size of something you'd find in the guts of a wrist watch) retaining spring thingy that makes sure the needle travels with the float and doesn't rely on gravity or fuel pressure to release the needle from its seat as the float drops in the bowl. When I cleaned the carb the first time and reassembled it, the float was in the bottom of the bowl waiting for fuel. Even after it filled, the vibration of the engine kept the needle loose enough to drop to allow fuel flow. But after sitting for a week in the closed position, the needle stuck in the seat and the engine quit as soon as it used up the fuel in the bowl. Lesson learned. So I hope this rather long post helps another Horseman out there somewhere, and thanks for your patience! Duff :hide: Share this post Link to post Share on other sites
Horse Fanatic 50 #2 Posted September 19, 2009 Duff, I also have a 1989 312-8 which I bought new. When the machine was a few years old I had that problem of the needle sticking shut. The dealership said bring the carb in and they would solve the problem, which was to add that clip which holds the needle to the float. the engines didn't come with it (or at least all the time) and that item could be added to solve that problem. So, it's quite possible you didn't lose that part when you rebuilt your carb, it may have never had it and never needed it until now. Glenn Share this post Link to post Share on other sites
rick 246 #3 Posted September 19, 2009 My shed kept 1989 310-8 didn't have the clip, either. Thats how I got it for $150....... Share this post Link to post Share on other sites
Duff 206 #4 Posted September 20, 2009 Duff, I also have a 1989 312-8 which I bought new. When the machine was a few years old I had that problem of the needle sticking shut. The dealership said bring the carb in and they would solve the problem, which was to add that clip which holds the needle to the float. the engines didn't come with it (or at least all the time) and that item could be added to solve that problem. So, it's quite possible you didn't lose that part when you rebuilt your carb, it may have never had it and never needed it until now. Glenn Thanks, Glenn - that makes me feel much better. I try to be very, very careful when I'm charting new territory not to lose or break anything, but as you know, that little spring is a tiny sucker. And dang, Rick - that makes that ittyy bitty spring a valuable little item, doesn't it? Glad you got such a good deal on your machine! It will be interesting to see if the rebuild kits I ordered include it....... Duff :scratchead: Share this post Link to post Share on other sites
jpmcleod 4 #5 Posted September 24, 2009 Duff. I was reading your post and noticed you refer to your engine as a Kohler 12M. I just purchased a 312-8 with a Kohler 12hp Magnum. I want to know if the Magnum could be the original engine or a replacement. Also, can you tell me where to find the serial number on the tractor. Thanks. Share this post Link to post Share on other sites
Duff 206 #6 Posted September 25, 2009 Duff. I was reading your post and noticed you refer to your engine as a Kohler 12M. I just purchased a 312-8 with a Kohler 12hp Magnum. I want to know if the Magnum could be the original engine or a replacement. Also, can you tell me where to find the serial number on the tractor. Thanks. Hi, JP, This got answered in another part of the forum, but in case you read here first, it's an original engine. The Magnum series started being used in '86 or '87. The engine serial number should be on a decal on the motor shroud somewhere near where the throttle/choke assembly bolts to the engine. The tractor serial number should be on a decal on the fender pan on the left side, under the seat. If it's gone or faded out and you need to look up parts, try 21-12K806, which is an '89 312-8. The 312's in the Magnum era share so many parts that one IPL is just about as good as another. I've got an '89, an '88, and an '87 in various stages of rebuilding and I've yet to find a part I couldn't exchange among them. Lots of C-series parts fit a well. Duff :scratchead: Share this post Link to post Share on other sites
Duff 206 #7 Posted September 25, 2009 It will be interesting to see if the rebuild kits I ordered include it....... That itty-bitty spring that holds the needle valve to the float is NOT included in a carb rebuild kit, but that's the LEAST of my worries. Apparently the kit number I used is for the adjustable jet Walbro carb, not the fixed jet model. The needle valve and seat were entirely wrong, as was the replacement pin the float rides on (do those things really wear out?). In fact, the ONLY parts I could use were the carb bowl gasket and the bowl retainer screw gasket. So.....if anyone out there knows the right number for the carb rebuild kit for the Kohler M12 with the fixed jet Walbro, I'd be mighty beholden if you would let me know...... Duff :hide: Share this post Link to post Share on other sites
tractordave3128 0 #8 Posted September 25, 2009 mine had the same problem.....all i did was a tear down and i put it toghether and it worked again i thought it was the needle sticking but this confirms itn thatnks Share this post Link to post Share on other sites
jpmcleod 4 #9 Posted September 25, 2009 Duff. Thanks for the info. When I start my teardown, I will look for the numbers. When I got it home yesterday, it was raining so hard I just parked it in the barn and went into the house. Upon intial inspection, the tractor appears to be complete with the exception of one headlight basel on the right side. As I get into it, maybe I can find one to fit. Again, thanks for the answer regarding the Magnum engine. Share this post Link to post Share on other sites
rick 246 #10 Posted September 26, 2009 Duff- the kit I used was Kohler 25 757 11-S, everything fit, and it contained the spring. Kohler lists two kits for the Walbro supplied 1" venturi carburetors, 25 757 08 and 25 757 11(-S). The Kohler p/n should be stamped on the edge of the mounting flange, probably on the bottom side. If you can get the number, it may solve the problem Share this post Link to post Share on other sites
Duff 206 #11 Posted September 26, 2009 Rick, thank you VERY MUCH for the numbers! And JP, those bezels are still available and not at all expensive from the parts houses. I'm not at home right now but will get you the part number when I can. They're sold in pairs. Thanks, guys! Duff :scratchead: Share this post Link to post Share on other sites
Patriot07 0 #12 Posted October 11, 2015 So is there a part number for the spring? Share this post Link to post Share on other sites
gwest_ca-(File Mod) 11,322 #13 Posted October 12, 2015 October 1990 2-page service bulletin on the subjecthttp://www.wheelhorseforum.com/files/file/883-wh89-90-t45-hard-starting-kohler-engines-with-1in-walbro-carbspdf/Garry Share this post Link to post Share on other sites
