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Is there any cure??


Spencyg

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Well...the beloved 7016H is finally up and running after a horrific engine rebuild. I'd say it is at about 90% of where I'd like it to be (mechanically)...my biggest problem is that the engine still requires the choke to be engaged to run. With the choke on, it runs fine and I can get the full throttle range. I have all new gaskets and I believe the entire intake system is pretty well sealed up. The one place that is suspect is the throttle plate shaft. It has about 1/64" of play in the bushings and I think this is where the extra air is coming from. Is there any fix to this problem? I have thoughts of making a new shaft, but I don't have access to the proper machine tools. Is there a way to install a rubber gasket of sorts? Thanks for suggestions. Its SO nice to have my tractor back and operating. Spence
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I have the same problem. If you find a fix would you let me know. thank you, Ikipp@netzero.com
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I've heard of people re-bushing the throttle butterfly shafts... though I've never done it.
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I havent tried to buy one but i was told there is a kit available thru dealers to drill and rebush them.
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Spence, before you go to the trouble of rebushing the shaft on the carb. or replacing it, you might want to be sure the slop in it is the problem. You could seal the ends of the shaft with a tiny piece of tape, or pack something around the end like modeling clay. Be sure the shaft ends are sealed up, restart it and see if it runs any differently. At least you would be sure if that is where the problem is or not. I bring this up because i have a lot of old engines, and many have that much or worse play in the throttle plate shaft , and don't seem to be affected by it too much. Dave
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SPENCE, YOUR HIGH SPEED MIXTURE SCREW SHOULD BE ABLE TO OVERCOME A LEAN MIXTURE CONDITION CAUSED BY A WORN THROTTLE SHAFT. I WOULD SUSPECT INSUFFICIENT FUEL BEING DELIVERED TO YOUR CARB. MAYBE A BLOCKAGE IN THE FUEL LINE INLET AT THE GAS TANK? IF NOT,TRY RUNNING THE ENGINE AT FULL THROTTLE PLACE YOUR HAND COMPLETELY OVER THE TOP OF THE CARB TO BLOCK OFF ALL AIR. AS THE ENGINE BEGINS TO STALL OUT REMOVE YOUR HAND AND LET THE ENGINE RECOVER AND REPEAT A FEW TIMES. SOMETIMES THE INCREASE OF VACUUM AND FUEL ON THE MIXTURE PORTS WILL DISLODGE DEBRIS THAT COULD BE BLOCKING THE FUEL PASSAGES. JUST A THOUGHT.:) MARK
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I will try those things. My fuel supply seems to be sufficient, but I won't rule out anything. What else would be causing the engine to only run with the choke on? I thought that maybe playing with the idle air needle would effect things, so I turned it all the way in. The engine would run fine on the upper end of the RPM settings, but wouldn't idle....so now I think it isn't the leaky throttle shaft. What else should I check? Spence
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I also had a lot of play in my throttle shaft on my 7014. I am assuming your carb is the large two piece type like mine. My problem was surging though. I rebuilt the carb, replaced all inlet gaskets, lapped the needle seats, everything I could do. All the tuning would not take the surge away. I read the repair manual about replacing the bushings. Went to my local briggs dealer and there is no part number or way to order the bushings through him. So I ordered a new upper carb body (around 40-50 bucks). I installed that and there was no more surging problems. I am not saying this is your problem, make sure you eliminate everything else. In my case that amount of play definitely had an effect.
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You might change your float adjustment a little richer....... May not be the cure, but its easy to do.
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My float is not adjustable (as far as I can tell). There is a small metal tab on the top of the float that fits into a small clip on the float valve...it pulls the valve open, and pushes it closed. Can I bend the small metal tab? I am also getting surging Srwven, so maybe it is a combination of things. Spence
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Bending that tab slightly is how you adjust the float level. Your high speed adjustment is the one on the bottom of the float bowl and the idle is the one on the top. Try setting them each at about 1 1/2 to 1 3/4 turns out, then start it, turn the bottom one and see if you can get to the point where you can take the choke off. If you can then run the engine at full throttle and adjust the bottom one in till it starts to run bad, then back out till it clears up again, then continue out till it runs bad again. pick a point about midway between the 2 settings. Idle engine holding the butterfly on the idle stop (idle adjustment screw) and repeat with the top adjustment screw. It should get you real close. Set your idle stop screw where you want it and see from there how it runs. If that smoothes it out so it runs decent once you put it under load you may have to adjuct the bottom screw just a tad in or out to smooth it out while the engine is working hard. If these steps don't straighten it out then you know you have another problem, but this is free and easy.
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Which way do I want to go to richen the bowl setting? Should the bowl sit higher or lower? I would assume higher, but it seems as though flooding could be an issue. I will try playing wih the mixtures, but It seems that they aren't doing as much when I adjust them as I thought they would. Spence
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Yes. Higher (mashing the tab closer to the float) is richer. Be very careful when you do this, floats are easy to bend up as it is very weak metal. While you have it apart, it is a good time to make sure everything is good and clean in there. By chance, did you convert from points and condenser ignition to the electronic "magnatron"?
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I have already rebuilt the carb yesterday, and it is all cleaned out. I converted from Magneto ignition to 12V auto coil using the standard points, and a new 12V condenser. It seems to be working very well, but I had to reduce my points gap down to about 0.014" instead of the 0.020" called out everywhere. Spence
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Guys, I have re-done the throttle shaft on two Kohlers. Haven't had to do a B/S yet. With the first one, I bought the kit from a dealer. It came with parts for both throttle and choke shaft for all the single cylinder cast iron engines, bushings, and a drill to enlarge the hole for the bushing. The second on whas a homemade modification. I had a left over throttle shaft from the old original kit, but made my own bushing. The Kohler carb has a counterbore in the carb where the throttle shaft goes through. I machined an aluminum plug to fill the counterbore, staked it in and drilled a new hole for the shaft. Both methods work very well. Adjustment of carb will compensate for a worn shaft, but the engine has a tendency to sputter randomly when the shaft is worn. The rebuild kit from Kohler was pricey if I remember correctly, around $35 ten years ago. I don't know the part number, and neither did the shop I went to. Got the number from a friend and then the shop ordered it for me. Made the insert bushing last summer because I couldn't find the part number again to get another kit. I'm pretty sure B/S parts are available also. I think you can order a smaller kit for the specific engine.
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There are throttle shaft bushings available, briggs P/N 691769. However the parts books are kind of fuzzy here. I guess you are going to see if you have have bronze bushings there now and if there is this might or might not do it. Some of the 32 CID engines show it and some don't.
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I have repaired them a couple of ways.If you are cheep like me try and sodier up the low spots on the shaft and then file the sodier down to make the shaft round .It does last a long time and does not cost much.Or just go out and buy a new shaft.Bob
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Sandy Lake Implement has replacement throttle shafts and bushings. I haven't actually got around to installing them, but both my tractors have this problem, and the one I don't use surges pretty bad. I believe a plugged jet can cause surging, as well.
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I was able to get the engine running last night without the choke by turning the high speed adjustment and idle adjustment WAY out (probbaly 2.5-3 turns each). It also sputters randomly, so it sounds like fixing the throttle shaft is next. Thankgs fellas...as usual you are all right on the ball. Spence
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