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Jeff Mead 09-01-2012 14:37:31 209.74.116.166 Report to Moderator	I have finished restoring my 8N. I went to start it last week and found out my floats were hung up after 2 years of sitting on bench. I cleaned them and everything is great (there). I am not getting any spark. I pulled all 4 plugs and rolled it over. Everything rolls just great as it ran like a champ before I tore it down 2 years ago. the only thing I had to do then to get it going was a new battery and starter. What would you suggest as a starting point. It has all new harness, plugs, wires, points, condensor, cap, etc.... [Reply]   [No Email]
Jeff Mead 09-01-2012 15:18:51 209.74.116.166 Report to Moderator	Re: no spark on 8n in reply to Jeff Mead, 09-01-2012 14:37:31   It is a 6V, side mount. I put the new harness and so forth on after I had finished repainting the body and so forth. I would not doubt a bit that it was the original harness (it was in bad shape. So it was probably about 2 to 3 months ago. I have plenty of gas flow.   [Reply]  [No Email]
old 09-01-2012 14:57:06 209.86.226.19 Report to Moderator	Re: no spark on 8n in reply to Jeff Mead, 09-01-2012 14:37:31   You say new points but since you have been working on it for 2 years when did you install them?? As Bruce said we need info like 6 or 12 volts front or side mount distributor etc. Hard for us to help you help your self with the lack of needed info   [Reply]  [No Email]
Bruce (VA) 09-01-2012 14:50:13 24.125.80.178 Report to Moderator	Re: no spark on 8n in reply to Jeff Mead, 09-01-2012 14:37:31   " What would you suggest as a starting point." Telling us if it's 6v or 12v & if it has a front or side distributor would be a good place to start. It takes three things for an engine to run: spark at the right time, compression, & fuel in the right mixture. For the moment, forget about compression (more on that later) & concentrate on narrowing the problem down to spark or fuel. There are three very important tools you always need to have in your N tool box: a 3 inch piece of wire w/ alligator clips on each end, an old spark plug w/ the gap opened to at least 3/16” ( ¼” is better) and a 7/16 box end wrench. (see tip # 50 at the link below) And, you really do need a working ammeter on the tractor; it is a very important diagnostic tool. With these tools, you can quickly narrow down most N problems to spark or fuel. First, check for fuel. Get a can & put it under the carb. Remove the bolt in the bottom of the carb; as long as the fuel is turned on, you should see gas flowing out of the carb. Let it run for at least 30 seconds. If it’s a dribble, or runs for 5 seconds & stops, or none at all, you have solved half the problem: it’s fuel related. If gas flows well out of the carb & only stops when you turn it off at the sediment bowl, chances are very good it’s not a fuel problem. So, next, turn the key on, crank the engine & look at the ammeter. What is the needle doing? Does it show a constant discharge, no movement at all, or does it move back & forth slightly? Next, get the old plug, ground it to a rust & paint free spot on the engine, turn the key on & crank the engine. If the spark jumps the 3/16” gap, you probably don’t have a spark problem. If it won’t jump the 3/16” gap, you have a spark problem. If the ammeter needle shows a constant discharge, or doesn’t move at all, that also tells you that you have a spark problem. Jump the ignition switch w/ your jumper wire & see what happens. If it runs, you found the problem. If it doesn’t have spark after you jump the ignition switch, post back for more info on further troubleshooting. (and do not forget to turn the ignition switch off; see tip # 38) If it does not have gas coming out of the carb at a steady stream w/ the bolt out for at least 30 seconds, you have a fuel problem. First, remove the gas cap. Your vent could be clogged & it vacuum locked. If that doesn’t work, tap the carb bowl w/ a hammer handle in case the float is sticking closed. (don’t whack it w/ the head of the hammer; you can crack the bowl). If you still don’t see gas flowing, the N has three fuel screens; one in the brass elbow, one in the top of the sediment bowl & one on the stem of the sediment bowl in the gas tank. Check the screen in the elbow & the screen in the top of the sediment bowl. (don’t worry about the one in the tank) Both probably need to be cleaned. If you have the fuel knob turned on all the way, & 1 gallon or less in the tank, it may be trying to feed off of the reserve inlet which is probably clogged. Only open it 2 full turns. Put at least 2 gallons in the tank. (and do not forget to turn the gas off; see tip # 9) You need to add 2 or 3 tblspns of oil to each cylinder to lube the walls & help w/ compression on the rebuild. There are ways to check for spark & fuel that work & ways that don't. For example, having gas to the carb is nice, but having it past the float is what counts! That’s why removing the 7/16” bolt in the bottom of the carb is the way to check for fuel. And, same thing w/ spark at the plugs. Some folks think that checking for spark means pulling a plug wire off & looking for one. Well, it's the distance the spark jumps at the plug that gives you the info you want. It takes about 17kv to jump a 3/16" gap & 22kv to jump ¼” in the open air. Remember, it’s 14psi outside of the engine & about 90psi at a 6:1 compression ratio in the cylinders & compressed air creates electrical resistance, so you really need the 17-22kv to fire the plugs when the engine is running. A store bought plug checker will work better than an old plug because it won’t shock the snot out of you like an old plug might! 50 Tips   [Reply]  [No Email]
Jeff Mead 09-01-2012 16:50:43 209.74.116.166 Report to Moderator	Re: no spark on 8n in reply to Bruce (VA), 09-01-2012 14:50:13   Also, I forgot to mention, the ammeter shows a constant discharge.   [Reply]  [No Email]
Bruce (VA) 09-01-2012 19:15:57 24.125.80.178 Report to Moderator	Re: no spark on 8n in reply to Jeff Mead, 09-01-2012 16:50:43   So, key on, the meter shows a discharge? Key off & it doesn't? Does the needle move at all when you are cranking the engine? 50 Tips   [Reply]  [No Email]
Jeff Mead 09-01-2012 16:48:50 209.74.116.166 Report to Moderator	Re: no spark on 8n in reply to Bruce (VA), 09-01-2012 14:50:13   I jumped the key swith with no luck. I read tip #38 and I had indeed (before all of this) left the key on and drained the battery completely. the points look fine and the ignition switch is still good as my polarity tester lit up just fine from side to side. How do you tell if the coil is bad?   [Reply]  [No Email]
old 09-02-2012 10:36:14 209.86.226.58 Report to Moderator	Re: no spark on 8n in reply to Jeff Mead, 09-01-2012 16:48:50   Points can look fine and not be worth 10 cents. Leaving the key on can cause a lot of odd problems. I would run a hot wire from the ignition side of the battery which in this case of still + ground would be the - side any how hot wire it right to the coil an then check for spark. If you have spark then your problem is from the coil back if no spark your problem is from the coil forward and it is time to open up the distributor and make sure when you open the points by hand you have spark at them. No spark at the points equals bad points and you can not see if the points are bad with your eyes   [Reply]  [No Email]
BillM (OH) 09-01-2012 19:50:59 173.81.81.180 Report to Moderator	Re: no spark on 8n in reply to Jeff Mead, 09-01-2012 16:48:50   I diagnosed a bad coil the other day with a no spark condition. check voltage to coil primary if yes, check distributor for grounds and continuity if OK, check points gap. if OK, check if points will spark when you open them if yes, check cap for carbon track, cracks, etc. , if OK, replace condenser, if still no spark, pull high tension wire from coil at distributor and see if it will throw a decent spark when held near a good ground - mine did not, so I changed out coil and all works fine. I always have a few spare electrical system parts laying around, so not much to it.   [Reply]  [No Email]
Bruce (VA) 09-01-2012 19:14:25 24.125.80.178 Report to Moderator	Re: no spark on 8n in reply to Jeff Mead, 09-01-2012 16:48:50   " How do you tell if the coil is bad? " You check for spark just like I told you to do. Does it have a spark that will jump a 1/4" gap? Coil problems are difficult to diagnose. For starters, round coils are pretty robust & square coils aren’t (because of the difference in insulation used), but neither one will hold up to a poorly done 12v conversion that allows too much current to the coil or leaving the key on (see tip # 38). Too much current creates heat which melts the insulation. Insufficient resistance in a 12v conversion will do the same thing. Rarely do coils just “go bad.” There are a few ways to see if a coil is bad, but it’s not possible to determine if a coil is good w/o some expensive testing equipment. If you detect a dead short or high resistance in the coil w/ an ohm meter, it’s bad. If it’s cracked, it’s bad. If a sidemount coil w/ battery voltage to the primary will not jump a ¼” gap from the secondary wire to the block, it’s bad. But, here is the hard part: even if you do not detect a short, even if it will produce a spark, even if it’s not cracked, that doesn’t mean the coil will work when it’s hot & under a load. So, it’s a process of elimination. If the tractor starts & runs fine for 30 minutes or an hour then cuts off & refuses to re-start, and you checked for spark at the plugs & it had no spark at all, AND you have the correct voltage at the coil that’s a good sign that you have a bad coil. Let it cool off, restart it & if you have a good spark, odds are it’s a bad coil. But, even then, you might end up w/ a spare coil on the shelf! Bottom line.......coils do go bad, but I'll venture a guess that 75% of new N coils sold today are sold to folks who do not understand how to diagnose a poor spark problem or how a coil works. So, for those who don’t know any better, in a no spark situation the first suspect is usually the coil……and, more often than not, it isn’t the problem. " I had indeed (before all of this) left the key on and drained the battery completely. the points look fine' OK.......you left the key on......the battery drained......and the points are ok? Really? If the points were closed w/ the key on, they burned up. Otherwise, you have a weak battery. Charge it. 50 Tips   [Reply]  [No Email]