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big ten ignition problem


MarkH

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When I hook a spark tester to my spark plug wire it isn't giving me a spark, however it will on the spark plug. I'm told that if it isn't jumping the gap on the tester it isn't enough spark. It had a briggs part number 398811 armature-magneto on it which is supposed to be an electronic ignition, or am I wrong? It has the plug wire and then two wires hooked on a slide connector to the mag side. one wire was going to the switch and the other was not hooked to anything. The mag has a metal tab on the bottom which I assume is the pickup for the ignition. I went to the dealer and got a new mag with the same part number(398811) and put on the same way and still not jumping gap on tester. Am I expecting too much spark? does the other wire have to go somewhere? I even left the ignition switch unhooked in case it is bad. any suggestions? Mark
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Mark, do you have the briggs+stratton ignition tester? I also do and kept thinking one of my machines wasn't getting any spark, problem was I tried testing in areas where the natural outside light is too bright. I tried it in a darker place and the spark occured. The best way to test is at night with the lights off and someone holding a flashlight in case of something happening, good luck,-BradW
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Hang onto the wire and crank it over.That will tell you if there is spark.Jumps start the old pacemaker also.Don't try it as it does not feel good and does not tell you how strong the spark is.I use a run of the mill tester but that does not tell you if the coil is going bad.You can not tell how well it is sparking at high speed .The model 9's 14' and 19's just have coil problems and the only way to fix them is to put in new coils .Bob
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The 398811 ignition armature is the Magnetron equipped (electronic ignition)armature. How fast are you spinning your engine? To generate spark, the engine has to turn faster for Magnetron than with the old point system. If the first 398811 armature was a new installation, did you have the flywheel polarized? Pat
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If the plug sparks see if the engine will run and how well it runs. If all is OK, then so what if the spark tester won't spark. My free thought and probably worth nothing. Roy
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Mark, are you sure your float is set correctly? They will leak if the float is set too high,-BradW
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I might not be too popular here after admitting this, but I also have a 212 john deere. That one still has the points. I tried the tester on that and got a beatiful spark. It is the briggs tester. I know I'm comparing points to magnetron so may be some difference there but I know the tester is Ok. It used to run with the old magnetron when my uncle had it then it sat 2 or 3 years. I had it running once when I first got it but it had a bad miss unless under load. I wasn't sure if that second wire went anywhere or not. By the way my dad bought a 212 allis chalmers the same year I was born and still has it. My john deere will never even come close to mowing as nice as the allis chalmers. Also the john deere mower deck is a big pain to put on. I still use it to plow my garden and with a snow thrower and it works good for that, but once the big ten and hb112 are finished I know I'll have a lot nicer looking lawn, and if I wanna use them for something else I won't mind taking the deck off. Thanks for the input, maybe I'll do what roy said and give it a try and see if it will fire. Mark
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It's not crazy to plow with a snowblower. I saw it for the first time this spring. We had a very dry winter. High winds this spring blew topsoil into ditches and yards. Some were like black snowbanks. People were using snowblowers to clean the fine drift dirt from ditches and yards. Worked very well. Pat
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Didn't proof read my last reply very well. Looks like I plow my garden with my snowthrower. Maybe thats why it breaks the shear pins. Some people will try anything once. I wonder if the guy that plowed snow with the moldboard plow gave me the idea. I just hope nobody wamts to see pictures. Seriously though thanks again for the input. Mark
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Mark, I take it your tractor runs then? If so, don't go by the tester 100% as mine is not 100% reliable, just as long as it runs, that is all that matters to me!-BradW
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the gas is leaking out the bottom hole in the air horn but only when cranking the engine over. If the spark isn't hot enough to burn the gas it is pulling in wouldn't the gas have to go somewhere. that is why I feel it is coming out the hole in the bottom of carb. I tried the carb off my dads 110 and it did the same thing, however works fine on his tractor. At first it would start and run for a little and then quit. When it was running it would not leak. It doesn't leak when just sitting there, only when you are turning it over and it won't try to fire, like it isn't getting enough spark or something. That is the only explanation I can find. I re-did the valves, rebuilt the carb with new float, needle butterfly, emulsion tube, gaskets and new gaskets on the intake. I also replaced the flywheel key. I need to get the flywheel repolarized yet. seems strange that it ran good when my uncle had it with the magnetron on and didn't have it polarized. After looking up magnetron on search section I found alot of good info. alot of good info on site period. you guys have a great site. I looked up emulsion tubeand found an article by Brent. Brent had a discussion titled 3416h carb and starting problems. In that discussion his tractor had exactly the same problem as mine. In his update he had replaced the points and condenser and this fixed the problem. I'd just like to get flywheel repolarized first and see what happens. If carb still leaks I'll have to try to work on seat for emulsion tube. I also tried several float settings, but if you hook up the fuel line and hold carb below tank level it doesn't leak so the float needle is seating. I'll just keep messing with it till I get it. thanks for all the advice. Mark
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You "re-did" the valves? Are they closing and seating properly? Sounds like you may have compression blowing back past the intake valve and forcing gas out the carb.
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I'm not sure if it will run or not, I didn't get it together that far. It would run before for a second and then quit. It would run gas out the bottom of carb when you cranked it. I think it was brent that had same problem with 16hp briggs. His was points and condenser. I pulled the motor off and replaced flywheel key. The only thing I may check is the book tells you to center the armature bracket mounting bolts with the magnetron ignition and mine is all the way to the left. I don't know if my timing could be off or not. it ran before like this so I don't kjnow if I should change or not. Redid carb so pretty shure it is ignition problem. it doesn't leak out carb till you crank it over. this is exactly what brent's problem was. Mark
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