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2 small problems.


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Hey folks. My 620 has a couple of issues. 1. Mowing along and happily running along at about 3K rpms in 2nd gear. When I get to a patch of clover or chickweed, the engine bogs down to about 2500 rpms and stays there until I raise the deck a little and slow down the forward speed. It used to roll right over these buggers without stopping for breath... 2. Again running along at above speeds and the "hot" light comes on very dimly after about 15-20 minutes. In daylight, you wouldn't notice it at all. At dusk, tho, it is easier to see it lit up. I am going under the assumption that it is for real, so I downshift to 1st gear for a while, and then have to shut it off to let it cool off for 1/2 hr. The cooling fins under the hood don't seem to be overly plugged, although I don't have an air compressor to blow them out...It's taking me a bit longer to mow the 3 acres than I'd like. Thanks. Jason
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The sending unit may be going out or may have lost calibration. I'd trace the wireing harness and check for a short but sounds like you need to replace the sending unit to be sure. I'm going under the assumesion that all your guards and tourqe tube belly pan are in place. As for the engine, I'd replace the fuel filter and sheck the flow out real well. Sounds like you may be loseing fuel supply and starveing the carb. Could be a sign of the points going out but I'd inspect the fuel real good first.
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quote:
Originally posted by Mick14
I wouldn't ignore that "hot" light,have you tried enriching the mixture.
By enriching the mixture, would you mean adjusting the air/fuel mixture on the carb? Does making it richer make it run cooler or hotter? Thanks. Jason
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quote:
Originally posted by D-17_Dave
The sending unit may be going out or may have lost calibration. I'd trace the wireing harness and check for a short but sounds like you need to replace the sending unit to be sure. I'm going under the assumesion that all your guards and tourqe tube belly pan are in place. As for the engine, I'd replace the fuel filter and sheck the flow out real well. Sounds like you may be loseing fuel supply and starveing the carb. Could be a sign of the points going out but I'd inspect the fuel real good first.
I looked under the guard behind the fuel tank and noticed that a number of wires are corroded and chewed up. So maybe I'll start with that. Can a fella find a sending unit for these machines anymore? Can I get an actual gauge that tells me the temp vs an idiot light? I don't have the original heat shields so I fitted in some tin between the carb/intake manifold and the exhaust manifold, as well as a couple of foil lined insulating pads used for sweating pipes in enclosed places...not pretty, but I like to think it helps.
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Sound like your 'mouse' on your pc has friends (MICE) LOL "I looked under the guard behind the fuel tank and noticed that a number of wires are corroded and chewed up. " I think Dave's point is well taken... JP
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A richer fuel mix will make the engine run cooler,not having the correct shrouds could be a big part of the problem,the vanes on the flywheel act as a fan and the shrouds channel that air over the head to cool the engine.
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Ron is correct about the temp light. It is for the tranny and you did right by downshifting. As for the engine shields, what you did was fine most likely. The belly pan needs to be in place to keep trash from entering into the engine and clogging the cooling fins. It also must be in place to force air over the tranny cooler. Also yop don't need an air comp. Just turn off the tractor and rub your hand gently over cooler to remove any excess grass. You can still get a sending unit from Simplicity, you can also replace it with a gauge, but you'll have to decide where to install a gauge. Too lean a mixture runs the cyl. hot. There is a fine line from correct mixture to too lean and since we think you may be starveing it for gas already, this could only lead to any heating and power lose.
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Sounds like it may be time to check points and timing. You can check for a lean fuel problem by pulling out the choke slightly when it loads up to see if that makes it run better. Temp switches do go bad. I replaced one several years ago and it only lasted 2 years. You can get a rough idea of oil temp by feeling the hydro filter. You should be able to hold your hand on it normally. Have you checked your fluid level? You can probably buy a transmission temp gage at an auto parts store if you want to go that way.
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  • 2 weeks later...
Hey guys. Been on vacation with the kids at grandpa's farm for a week. Caught some fish at his pond. Kids had fun. I'll try out these suggestions. Thanks so much! Jason
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In addition to the excellent adice above, I would pull off as many engine shrouds as you can get to, to see if you can find any indications of mouse nest, despite the fact that the "hot" light is not relevant to engine temp. It's a good idea to ensure there's no blockage of the fins, at least every spring, and more often, if you even suspect overheating. Somebody mentioned it's not possible to pull the all the shrouds without removing the engine...if that's true, you'll have to take off any you can, and peer around with a small flashight, dental mirror, etc..., and see what you can see. Just my thoughts....
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