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coulter 10-02-2012 06:25:44 74.76.8.98 Report to Moderator	my ford 8n starts and runs well when cold. after it has been running for awhile it quits and will not restart until it is cold. When i try and restart it hot there is no spark to the plugs. Where di I start? [Reply]   [No Email]
soundguy 10-02-2012 06:43:27 184.245.14.10 Report to Moderator	Re: no spark when hot in reply to coulter, 10-02-2012 06:25:44   i hesitate to mention it, as it is rare, and most people don't understand the role of the condensor well anyway... but. it is possible the condensor may be fialing shorted when hot..then self heal when cool. again.. quoite rare.. but does happen. if your no spark is not helped by a hotwire.. then do a continuity test onthe dizzy... that can help sniff out shorts.. including the condensor.. however time is of the essence... heat shorted condensors that self heal will fool the continuity test if you wait too long and let things cool down. [Reply]  [No Email]
soundguy 10-02-2012 06:39:24 184.245.14.10 Report to Moderator	Re: no spark when hot in reply to coulter, 10-02-2012 06:25:44   if no spark, look at bruces info. one quick thing to do is hotwire it and see if switch / resistor or wire connections may be the cause. [Reply]  [No Email]
pconnie 10-02-2012 06:37:56 67.72.98.45 Report to Moderator	Re: no spark when hot in reply to coulter, 10-02-2012 06:25:44   points are pitted or gap is too close.replace or file um and set um at 15 [Reply]  [No Email]
Bruce (VA) 10-02-2012 06:45:26 24.125.80.178 Report to Moderator	Re: no spark when hot in reply to pconnie, 10-02-2012 06:37:56   Nope. It starts & runs. .015? What if it's a side distributor? 50 Tips [Reply]  [No Email]
soundguy 10-02-2012 06:41:17 184.245.14.10 Report to Moderator	Re: no spark when hot in reply to pconnie, 10-02-2012 06:37:56   naw.. not even close. arced and pitted points don't self heal. he says it woont start hot but will start cold. if the poitns pitted and she stalled.. they wouldn't self clean when she cooled down. I DO agree that too close a gap will pit and arc points.. but they would require manual clenaing before thay'd be useable again. seems his restatrts fine cold.. thus ruling that out. rarely.. a condensor can go thermal and short though.. that will sometimes self heal.... [Reply]  [No Email]
pconnie 10-02-2012 06:47:15 67.72.98.45 Report to Moderator	Re: no spark when hot in reply to soundguy, 10-02-2012 06:41:17   my front dizzy 8 did the same thing..cleaned regapped points been running fine all year..i must of been lucky [Reply]  [No Email]
soundguy 10-02-2012 07:05:41 184.245.14.10 Report to Moderator	Re: no spark when hot in reply to pconnie, 10-02-2012 06:47:15   no.. different issue. you CLEANDED them, and then RE GAPPED them. this guy is not cleaning and regapping. his 'auto heal' 2 completely different issues. had you read my message you would have seenthe different poitns I was making. [Reply]  [No Email]
Bruce (VA) 10-02-2012 06:36:46 24.125.80.178 Report to Moderator	Re: no spark when hot in reply to coulter, 10-02-2012 06:25:44   It is important for you to tell us if your tractor has a 6 volt or 12 volt electrical system & if the distributor is on the front of the engine or on the side. The troubleshooting is different based upon the configuration of your engine. 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 & 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. Next time it stops, check quickly for fuel then spark. When I say quickly, I mean get off the seat, grab the tools & do it right then. Do not wait a minute or two. 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) 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]
kylemorley 10-02-2012 08:24:20 96.61.81.253 Report to Moderator	Re: no spark when hot in reply to Bruce (VA), 10-02-2012 06:36:46   When I was running a can coil with no ballast I noticed it would lose spark if I left the ignition on too long without the engine running. I always assumed this was from the coil overheating - if the points happen to be closed when the engine stops and the key is left on the coil sees more current than if the points were opening and closing. Or is it the other way around? If the ballast/coil mismatch is bad enough this can happen even as the engine is running - I had a VW years ago that was rewired without anyone noticing that there was supposed to be a resistance wire in the harness, and would start to run funny after an hour or so. Too many amps will usually kill a square coil pretty quickly, but some coils tolerate it better than others, and bounce back after being allowed to cool. Though it is likely that in the long run some damage is being done. [Reply]  [No Email]
MikeZ 10-02-2012 14:37:56 Report to Moderator	Re: no spark when hot in reply to kylemorley, 10-02-2012 08:24:20   Posted by kylemorley "Too many amps will usually kill a square coil pretty quickly" I have a 48 N 12v(EI) with a sq coil.With just a ballast resistor the coil was hot to the touch.So I removed the ballast and installed a one and two ohm resistor in series,bringing the amps down from 3.7 to two.It's been 2.5 yrs of Instant starts, hot or cold.After one hour of cutting grass the coil is luke- warm.The tractor runs great. Mike [Reply]  [No Email]
MikeZ 10-02-2012 14:45:35 Report to Moderator	Re: no spark when hot in reply to MikeZ, 10-02-2012 14:37:56   Posted by kylemorley "Too many amps will usually kill a square coil pretty quickly" I have a 48 N 12v(EI) with a sq coil.With just a ballast resistor the coil was hot to the touch.So I removed the ballast and installed a one and two ohm resistor in series,bringing the amps down from 3.7 to two.It's been 2.5 yrs of Instant starts, hot or cold.After one hour of cutting grass the coil is luke- warm.The tractor runs great. Mike [Reply]  [No Email]