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"Hot" light on 620


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Hey guys. After running my 620 over the yard for a while (30-45 min) my "hot" light comes on dimly. I didn't notice it until I was finishing mowing at dusk, then it was just barely lit. I had been running it in 2nd gear, so I went down to 1st gear, but the light never went off even with the cooling fins cleaned off. I mowed again a few days later, and started at dusk. The light didn't go on again until 1/2 hr later and I had it in 1st gear the whole time. The cooling fins were fairly clean. I can feel air movement over the fins, any ideas as to why the light comes on? If the problem is an overheating issue, what can I do to fix it?
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You'd need to test the sending unit to ses if it tripped at the appropriate temperatures. Do you have all the covers & drip pan on? Fluid level correct?
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Should have throttle at 3/4 or above when mowing. Might need to change the oil & filter. Use WIX or NAPA filter, 51307 or 1307. I use Dextron III. Check the filter holder for internal debri. Check all hoses to see if any are collasped. Cheers
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Tranny fluid level is ok, all covers are in place, except for the engine shroud, I have cobbled in some sheet metal to make as a heat shield around the exhaust. Not so sure about the sending unit. How do you go about testing it?
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Fram. Offhand I don't remember the number on it, it was the same type that was on previously when I got it from the previous owner. Maybe this reply wasn't helpful. I did change the tranny fluids last summer. Maybe I'll try changing the filter and the fluid here soon. Any possibility that the line running through the cooler is plugged? The hydraulic piston seems to work ok, except that I have to lift it up slightly every once in a while when mowing as the deck slowly drops without my assistance.
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Fram is not the correct filter! Change it. There could be a restriction in the cooler. Do not understand why you would have to "lift it up slightly every once in a while when mowing". You should be mowing with both hydraulic control levers full forward in the float position. This could be your heat problem.
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I keep the hydraulic control levers in the "hold" position when I have the deck at the height I want to mow at. It seemed when I had them in the float position, it would scalp the grass and the engine would bog down...Just yesterday I put an electric fuel pump, new points and condenser on this machine, and so far it hasn't died out after an hour of mowing in the hot weather...likely due to the mechanical fuel pump getting old. I'll try the correct tranny filter next. How do you clear a restriction in the cooler? New problem today. After 1 1/2 hrs of mowing in the hot weather, the engine is still roaring away and then I notice a bit of smoke coming from under the hood. Ugh. I now have a leak in the oil pan gasket. Fortunately I noticed it before it caused any problems.
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The mower height adjustment is mechanical re the the two T handles on the mower not the hydraulic lift. Run it the FLOAT position only! I doubt you have a cooler restriction if so compressed air after pulling the hoses. Also for the oil leak tighten the oil filter assembly and check to make sure there are copper washers installed. Do you have a manual for this tractor & mower? Cheers
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Running with the hyd valve(s) in Hold position should not affect oil temp. as these are open center valves - meaning when valve is in Hold position, oil flows through the valves and is returned to resevoir. Hyd cooling coil line likely not plugged either as that would lead to lift not working at all and/or the hose would blow off the inlet line. I'm betting the sender is bad.
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Thanks Mike and all. I truly appreciate your advice. I checked the area around the filter, there wasn't any leakage (unfortunately-that would be an easy fix). Checked at the base of the engine after cleaning the oily grass out and with the engine running, there was oil spraying out of the seam between the oil pan (?) and the engine block on the side of the engine next to the oil fill tube. Looks like it needs a new gasket. Apparently the only way to replace it is to take the engine out and flip it over to get access to the bolts...I have the engine mounting bolts out, but I am unable to remove the dual belts, and I am not seeing any obvious way to loosen the tension on these belts. I don't have the repair manual, unfortunately...Could you folks tell me how to get the belts loosened up so as to be able to remove the engine?
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Go to the top of this page click on simple tractors then look for the yellow box on your left halfway down the page put in your mfg #
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Go to this site and type in 1690283 for manuals. For your mower type in 1690074 http://www.simplicitytechpubs.com/techpubsearch.php
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To remove the belts, first put a strap of some type on the clutch pedal to hold it in the fully depressed position. This should create enough slack to work the belts off the pulley without loosening the tension spring. If you need a little more slack try lifting the front of the engine to tilt the pulley down. Remove the front belt from the front of the bottom pulley and let it hang on the engine pulley. Remove the back belt from the back of the top pulley and leave it on the bottom pulley. I assume you have disconnected the rear PTO drive disk if you have one. Reverse the above for reassembly. After reassembly, the tension spring should be adjusted to a compressed length of 7 3/4 inches. Adjust the nut on the bottom of the clutch actuating rod to provide 1 to 2 inches of pedal free travel.
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Ok. I got the belts off, after sweating a couple of pints...Cripes, that is one heavy "small" engine. It was quite a production extricating it myself...Hopefully it won't be like opening a can of worms replacing the gasket. My wife is now not so much thinking my tractor is so sexy anymore..."You paid 2700 for this tractor? You know you can get a new one at home depot for less than this?" I guess sometimes it's hard for others to see the beauty in these beasts... Meanwhile, keeping on topic, according to what you posted, Mike, it looks as though my "problem" with the hot light coming on dimly is actually normal? It doesn't come on brightly, but I guess I have never seen it lit brightly, even when I just turn the key on...which leads me to wonder if the bulb is defective? Can I use an oil temperature gauge in place of the dummy light? Thanks for your help all of you. Jason
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With the yellow wire connected to the hot light run another wire to ground from the yellow connection and the key on the hot light should illuminate brightly. If not you have a defective bulb or wiring. You can also remove the wire from the sensor and ground it and light will come on. When you turn the key to "Start" the HOT light should come on & go out when key is return to run position if not it's a wiring problem or bulb. Not sure what you mean by, "Can I use an oil temperature gauge in place of the dummy light?" Stick to what the factory has installed.
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I've had a powrmax a couple of years now, great tractor: thanks again to the list for all the help! I use it routinely for light work, and have used it several times under what I consider heavy usage: either pulling a full size disc or using the front end loader, sometimes for multiple hours at at time in 100 degree weather. My temp light has never come on brightly, (except when starting) but is always dimly lit when running. I typically run the old tired engine at only 1/2 to 3/4 throttle, and I've never had a temperature related problem. My manual indicates a dimly lit "hot" light is normal, though others with more experience on this list may disagree. As you start the engine (during cranking) the hot light will (should) light up brightly: this is the level of brightness you will see if you have a overheating problem, assuming your sender is working properly. IMHO, you don't have an overheating problem if the "hot" light is only dimly lit. Good luck with your tractor: they are amazing pieces of machinery. Mike Bennett Fresno, Ca
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By asking if I would be able to use an oil temperature gauge, I was wondering if I would be able to see what the transmission oil temperature actually is, rather than relying on a light that may or may not be functioning. But I'll try jumpering the light and see if it comes on brightly...After taking my engine out yesterday (and feeling relieved I don't need hernia surgery), I noticed the wiring under the dash is corroded and bare. I didn't check the wiring when I first got this tractor last year. The guy I bought it from said he went through the tractor and "totally rebuilt everything". I should have listened to the BS alarm ringing when I followed him out behind his shed and looked at it. He said it was his 12 year-old son's project tractor, so I imagine the guy helped his son with it, but then the boy screwed around with the carb and who knows what else. All in all, I still wouldn't give this machine up... I didn't need to loosen the oil pan bolts by the way. They were preloosened for me, and one had already fallen out and was stuck in the spot between the block and the starter. So now that I have the gasket kit for this engine, I am wondering what, if anything, you would use as a gasket sealer--specifically cylinder heads and oil pan. Thanks and have a great day. Jason
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