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heron

Sunstar PTO kills motor...?

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heron
Just wondered why when I engage the deck PTO the motor will die. It seems like it only does it when I first start it up and warm it up some. I'll have to engage it several times before it finally doesn't kill the motor and works. Once it's warm and has been cutting it engages fine the first time. No restrictions I can see on the deck or gearbox. I just had the deck apart and checked everything. Gearbox spins freely by hand. Motor has 580 hours. I've had it now for a couple of weeks and have cut a total of maybe 3 hours. I have noticed after I idle down and let it idle for a minute or so I get some slight blue smoke when it shuts down. Is this normal for the Kohler? I don't shut it down off high throttle. It's got the Kohler motor oil and filter...new, from the last owner.

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sammiefish
blue smoke is not normal for the kohler or any other gas engine it indicates oil getting burned by the spark plug this is not a normal situation to address the blue smoke (if it is oil smoke), you have either: bad timing, valves need adjusting, worn valves/seats, worn rings/cylinder, or possibly clogged breather filter

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HubbardRA
If your engine is turning at around 2000 rpm or more when you shut it down, the electronic solenoid will immediately shut off fuel flow to the carb and all of the fuel will be pumped out before the engine stops. If the engine is idling and there is still fuel in the carb when it stops, these engines will usually backfire with a very loud pop. This backfire, is not just annoying, but it can actually damage the engine.

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heron
Okay, could the PTO not engaging right away be due to a timing issue? Just don't understand why it works great once it's good and warm... I doubt the rings, seals etc... are worn at 580 hours but I can hear a little bit of an un-eveness at full throttle. I think if the compression was an issue it wouldn't fire up so well. It doesn't hardly even have to turn over much to fire up. Gas filter is new but I did find where one of the spark plug wires was impinged under some metal next to the motor. I may look at the plugs and wires. How do I go about checking timing on this motor? It starts great and idles fine and doesn't smoke at all when running and under load. So, I should shut it down at half throttle? Wow, never heard that one. But, never had a Kohler before.

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sammiefish
Sorry for my ignorance.. is the pto an electric pto? Is yours a battery ignition system? If so, my next question would be, how is the battery? I have a mower with electric pto that when the battery is low it will crank and start fine but the pto wont engage... that might be consistent with your observation that after the engines runs a while (charges up the battery) the pto engages fine...

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BLT
At what RPM do you engine the PTO? . The book say you should do it at a moderate engine speed , at least half or more throttle. That is partly to make sure you burnish the clutch face or extend the life of the clutch..

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heron
Sammie: Yes, it's a 97 Sunstar..electric PTO and battery ingnition. Battery is brand new from previous owner. He had a 600cca battery put in that doesn't fit perfectly but it works. Not sure if it's too much cca's for the tractor...I think it calls for a 400cca battery. Battery is right up there as I had it on a battery minder and it didn't take but a night to get it perfect. BLT: I engage at full throttle...so I should not? I'm new to this fancy electric PTO..my dad's Homelite T16 always had to be full throttle to engage the deck...? Upon further inspection tonight I found what I think is a leak in the front case of the motor. Oily at the bottom front of the motor. Doesn't look to hard to replace but I'd like to hear from you guys out there. Two weeks into the ownership of this thing and I'm getting nervous. The oil leak seems like something that has been weeping for a very long time. It was totally covered in built up grass and debris when I bought it. Maybe the previous owner did that on purpose...who knows. Ray is trying to send me the repair manual...which I really need. So, I've got a bluish haze...very slight when I shut it down, PTO issue and now maybe an oil leak. Not to mention I never heard back from anyone about the tranny oil leaking out of the top of the hydro when I filled it up. Got my work cut out for me. Good news is it still runs great and cuts as well as my Honda commercial push finish mower. My father in law cut his yard with it and thought he'd gone to heaven. He is not one to spend money on mowers..he is used to cutting with a 8 y/o Murray 18hp that he has to go over his pass three times to get all the sprigs of grass. On another note is there a better plug to run in these Kohlers? It's got Champion RCY12YC's in it...Is an NGK Platinum or other better for the Kohler Command?

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rokon2813
I am not at all familiar wit a Sunstar, but just for giggles, I worked on a Craftsman this summer that the pto was making the engine stall. Turned out the seat switch had more than 2 wires? Was making good enough connection to start the tractor, but sometimes not enough to engage pto. The engine would shut down as if you got off the seat. Worth a shot.

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heron
Rokon: Thanks for the lead. How did you remedy this? The seat switch does not work right and was something the previous owner told me. That may well be the issue. I'm not sure how the switch is supposed to work on this tractor. I know sometimes I have to be on it to start it and other times I don't. The PTO will engage off the tractor..previous owner showed me that when I was checking it out. Can anyone tell me how it is supposed to work and how can I disconnect it or fix it? I don't mind replacing the switch but I just ordered from Jacks last week.

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rokon2813
I just cleaned the electrical contacts and lubricated the button on the switch. This one happened to be a plastic button, had some dirt and scratches on it. It must be okay, it never came back....

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comet66
If I don't allow my Command to fully warm up before engaging the 60" deck, it will stall unless I give it a little choke until the deck comes up to full RPM. That is a heavy load to get spinning. I'm guessing that by "Upon further inspection tonight I found what I think is a leak in the front case of the motor." You mean behind the PTO clutch. That would probably be the main seal. Easy problem to correct. Remove the clutch and the seal is exposed. I think the dash next to the engine speed lever is marked at what level the engine should be turned off. Battery is not a problem as long as it is secure and not resting on anything that could wear a hole in the case. I'd guess the hydro leak from the breather is an indication of over full.

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heron
Okay, that makes me feel better about the PTO and the warming up. Yes, I'm glad you told me about the breather. I had put 5.5 qts in and all of a sudden fluid is coming out at the 90 degree fitting on top of the hydro... Is the clutch anything difficult or straight forward to remove? I'm waiting for Ray to send me a repair manual for the tractor but I'd like to get the seal done. Is there anything else oil can come out of that would saturate the front bottom of the motor? When I picked it up a couple of weeks ago it was caked with debris and oily residue all over the front and side of the motor. The seal would do this right? Any idea why there would be a little un-eveness in the motor at higher RPM's? You can barely hear it but not sure what could be causing it. Plugs look good although I'm changing them, gas/filter are good, carb seems fine. Have you had any particular issues with your unit in this manner?

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RayS
Sent epair manual last night. I work 2nd shift so it was late. The uneveness could be a lean - rich mixture issue try adjusting the high speed air mixture screw. You should have one. My Command is 5 years newer than yours and it does.
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heron
Thanks Ray...I just looked it over. I'm going to go ahead and replace the switch on the seat. Manual says there can be two. Any idea how many a 97 Sunstar has? I'm ordering up switch and seal for my oil leak. If I change the oil seal on the 20hp command do I need any other parts? Does not seem to be any on the schematic at partstree.

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stevenj
Not sure if the later Sunstars had the interlock module or not, but I believe the engine should stall if the PTO is engaged and then the operator lifts off the seat. Stands to reason if the interlock module thinks the operator is off the seat and the PTO is engaged, then the engine would shut down also. The only way to test an interlock module is with the specific Simplicity tester. What is your model number? http://bsintek.basco.com/BriggsDocumentDisplay/default.aspx?filename=jgEGGP_ezO3tG5ERl7mRgtLvBCd6

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