ebinmaine 67,621 #1 Posted May 19, 2021 I got a carburetor from @mcfarmall Kyle so I could rebuild it for him. Turns out the bottom throttle shaft bore is horribly worn. I made a video with the help of my Videographer BBT to show what to look for, for future reference. This also shows the location of the replacement washers/bushings after installation. (Someone else had done this one in the past.) 4 1 Share this post Link to post Share on other sites
lynnmor 7,308 #2 Posted May 19, 2021 The washers are only a Band-Aid, the real fix is to bore the body to a size that will clean up the wear, followed by making a new shaft to fit the new size. The area where the throttle plate is can be cut down to the original size to maintain air flow. Another option is to bore the body as above, but add bushings to restore the original size, then add a new throttle shaft. Fairly easy job for any good machine shop. 1 Share this post Link to post Share on other sites
pfrederi 17,741 #3 Posted May 19, 2021 Sometimes things are beyond reasonable repair efforts. Not like this is some unusual rare never to be found carb... I just sprung for a kohler carb shaft replacement kit. List price is $90 i got one for about 45. All it gets you is a shaft a top bushing and some screws... 1 1 Share this post Link to post Share on other sites
ebinmaine 67,621 #4 Posted May 19, 2021 6 hours ago, lynnmor said: Fairly easy job for any good machine shop I'm a big believer in rebuilding the old Kohler carburetor vs buying a new replacement. I'm also a big believer in "Use what ya have" and really looking for the VALUE of things. If I had my own home machine shop I'd absolutely repair something like this. In my area you cant even walk into a machine shop for less than $80-$100 minimum. A job like this would be at least double that or more. At that point the value of the repair is long gone in comparison to finding a different good used carb and rebuilding that. 1 Share this post Link to post Share on other sites
stevasaurus 22,764 #5 Posted May 19, 2021 Eric, I enjoyed the video and finally getting to hear your Maine accent. Just so you know, there is an "r" in carbonator, and there is no "r" in wash. I miss talking like that. 3 Share this post Link to post Share on other sites
squonk 41,155 #6 Posted May 19, 2021 48 minutes ago, stevasaurus said: Eric, I enjoyed the video and finally getting to hear your Maine accent. Just so you know, there is an "r" in carbonator, and there is no "r" in wash. I miss talking like that. My relatives on my dads side are from Northern Maine. If it wasn't French is was Tracta, Kaaa. paarch ect. The first time the wife and I watched "Down East Dickering" I was on the floor laughing. Wife said "What is so funny?" I just told her you had to be there! 2 Share this post Link to post Share on other sites
ebinmaine 67,621 #7 Posted May 19, 2021 Just now, squonk said: My relatives on my dads side are from Northern Maine. If it wasn't French is was Tracta, Kaaa. paarch ect. The first time the wife and I watched "Down East Dickering" I was on the floor laughing. Wife said "What is so funny?" I just told her you had to be there! Yeah you just can't understand how thick that accent is in DownEast unless you've actually been there to listen to an old-timer. Share this post Link to post Share on other sites
squonk 41,155 #8 Posted May 19, 2021 16 hours ago, ebinmaine said: I got a carburetor from @mcfarmall Kyle so I could rebuild it for him. Turns out the bottom throttle shaft bore is horribly worn. I made a video with the help of my Videographer BBT to show what to look for, for future reference. This also shows the location of the replacement washers/bushings after installation. (Someone else had done this one in the past.) Judging by those throttle plate screws, That carb came from Wisconsin! 1 Share this post Link to post Share on other sites
roadapples 6,983 #9 Posted May 19, 2021 Why is that, everyone has an accent but me... 1 1 Share this post Link to post Share on other sites
ebinmaine 67,621 #10 Posted May 19, 2021 33 minutes ago, squonk said: Judging by those throttle plate screws, That carb came from Wisconsin! How you figure? Share this post Link to post Share on other sites
squonk 41,155 #11 Posted May 19, 2021 Jim rebuilt a tractor using those style screws. 1 Share this post Link to post Share on other sites
Handy Don 12,237 #12 Posted May 19, 2021 2 hours ago, ebinmaine said: Yeah you just can't understand how thick that accent is in DownEast unless you've actually been there to listen to an old-timer. Ahyup. 1 Share this post Link to post Share on other sites
mcfarmall 11 #13 Posted June 8, 2021 Maybe I'll try to set this up on a right angle plate in the Bridgeport and re-bore those throttle shaft holes. The trick will be determining what surface feature Walbro used to locate off of in their machining process. Perhaps the float bowl O.D. gasket surface? I can get one location from the air horn gasket surface. 1 Share this post Link to post Share on other sites
pacer 3,173 #14 Posted June 8, 2021 2 hours ago, mcfarmall said: The trick will be determining what surface feature Walbro used to locate off of in their machining process. @mcfarmall is describing some of the reasons a machine shop can be so expensive -- set-up! Once its set up the actual boring and installing a bushing would take maybe 5 mins! But as he describes, getting to that point....... I had a front axle off of ---- I cant remember off hand what tractor, anyway it was worn badly so I think, heck thats no problem, just clamp it down on the mill table and bore it out for bushings - easy/peasy!! Some 3-5 hours later I had both sides done and one side was noticeably off! But on the axle that wasnt too big a deal, but that carb will have to be dead on or the butterfly wont fit.... 2 Share this post Link to post Share on other sites
mcfarmall 11 #15 Posted June 8, 2021 1 hour ago, pacer said: @mcfarmall is describing some of the reasons a machine shop can be so expensive -- set-up! Once its set up the actual boring and installing a bushing would take maybe 5 mins! But as he describes, getting to that point....... I had a front axle off of ---- I cant remember off hand what tractor, anyway it was worn badly so I think, heck thats no problem, just clamp it down on the mill table and bore it out for bushings - easy/peasy!! Some 3-5 hours later I had both sides done and one side was noticeably off! But on the axle that wasnt too big a deal, but that carb will have to be dead on or the butterfly wont fit.... Time spent making a dead nuts setup is critical. Being in the machine trades and having decades of "government jobs" under my belt, I have a knack for it. Most of the machining I do at work is on critical (read "extremely expensive or super long lead time") components for pharmaceutical manufacturing equipment and usually made of difficult to machine materials like a variety of stainless steels, hastelloy, etc.. 1 Share this post Link to post Share on other sites
ebinmaine 67,621 #16 Posted June 8, 2021 Now keeping in mind that I am no machinist and I only have the most minute bare bones basic understanding of what you folks can do... My best thought on that would be to back off the idle screw so that the plate will sit as flat and flush as possible in the bowl and then base your guessing/measurements on where that shaft sits in the worn oblong hole at that point. Even when new there's a tiny bit of slop in there creating flexibility of movement. Share this post Link to post Share on other sites
