8n runs until hot

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8n runs until hot

john	i need some advice please. back in the spring i did the tune up thing. points cond. coil plugs. tractor ran great all summer. about 3 weeks ago i was turning land tractor started was running good after about 30 mins it started dieing out. if you put it n neutral or depressed clutch engine caught back up but would die out under a load. had a skip/ backfire every so often while idleing. shut it off after a couple of hours went back sstarted ran fine for about 30 mins again and then same thing. got it to the house and replaced oil pan gaskets. [ it was leaking] replaced head gasket and coil. used tractor for about 2hrs last weekend it was perfect. i turned land for about an hour and a half today perfect. then it just started doing the same thing. i loosened gas line at carb gas runs out, blew thru gas line emptied sed bowl looked good, but it dies under a load and at idle engine doesnt sound like its at full song and a backfire every so often. i am willing to bet n a couple of hours after it has cooled back down i can go get on it and drive it back to house no prblem. any ideas? any would be appreciated. thanks
john	yeap gave it about an hour and a half to "cool" down ran good for about 25 min and samething
Bob G	Which 8n is it and is a 12 volt or 6 volt? Front mount distributor style has problems with the coil overheating and doing what you are talking about. The ballast resistor in system is a must have and if it is a 12 volt conversion an extra resistor is requirred unless you have a 12 volt coil. also the fuel flow should be check thru the carb, not just to the carb. remove plug on bottom of carb and check for flow. should flow a pint in 3 or 4 minutes. This also checks the flow thru the float needle valve and the screen in the carb. let us know what 8n you have. Good Luck
john	it is a front mount dist. i put a new one on in the spring and then when this prob started i went qnd got 2nd one and put on.the prob didnt go away then either. i will check the flow in carb as you sugeste3d 2orrow. thank you Bob G. i will let you know my findings.
Bob G	You don't say if it is a 12 volt or 6 volt. you may be hurting your coils if the resistance is not correct.
john w crews	it has been converted to 12 volt system.
Bob G	Since it has been converted to 12 volts I would check to make sure it has the orginial ballast resister and if it still has the orginial style 6 volt coil, that it has an aditional reistor. If you have a 12 volt coil then the ballast resistor is the only one required. Either way you need the ballast resistor. I would run it until the problems happens and right then check to see what kind of spark you have. You might check it before you run it to get a comparision to go by. It also could be the ignition switch getting hot and failing. Make a jumper to bypass it and see what happens. When parts in an electrical circuit gets hot the resistance increases and current flow decreases. If you have a volt meter you can check for voltage at the top of the coil also. It will be a lot lower when the points are closed than when they are open. You can crank the engine over and watch the amp meter. It should show more discharge when the points are closed and less when they are open. look for the movement. The most important thing you can do is to check for spark as soon as you have the problem. Once you determine if you have a good spark or not, you iwll know what direction to go in. You can make a test plug from an old spark plug. Open the gap up to 3/16". Should jump that much and be a fairly blue spark. Like I said check it both cold and hot. Keep us posted
Clintmn	If'n I could only have one guess, I'd say every one else was right and it's a coil heating up,just because of the length of time it takes to start acting up. If it started running crappy after a couple of minutes, I'd say condensor. I've never understood why they put those things in tuneup kits. You are basically swapping out a proven part with no expiration date for an unknown. If you saved your old parts, it's worth a try, but I'd still say"coil"

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