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waxen

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Hello Just scored a 3414s with 36" tiller and 42" deck ,The engine is a 13 horse Briggs.........with a little problem, it just wont fire. There is compression There is spark There is fuel I have taken the manifold off and sprayed Aerostart directly onto the valve stem and it still wont fire. The coil tests ok , the spark jumps a 4mm gap as far as i can tell timing isnt adjustable ,the points gap is 15 thou. Any ideas ???? Apart from that she's a beut little unit and i'm looking forward to restoring her. Cheers w
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wayne i would remove the lywheel to check that the key is not sheared. You may be sparking but at the wrong time, this key is what holds the engine in time. As far as the point gap goes I will have to check but i think it has to be 20 thou not 15; you may also want to check the armature air gap which is Ten thou. i will try to confirm the point gap for you mabee sombody else can confirm?
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Welcome Wayne, I would suggest the same thing. Check for a sheared key. If you have all the ingrediants for ignition and it won't light, they can't be getting there at the proper time.
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Hey Wayne, welcome to the site. No such thing as a "Newbie Question" around here. I was a "newbie" once, but I got over it. Nice to see an Australian joining the site. I agree with the other posts. If you have fuel and spark. Then it can only be one of two things, flywheel key sheared or a shorted sparkplug. The shorted sparkplug thing happened to me about a year ago. I worked on everything else and was totally confused till I replaced the plug. I had even checked the plug and set the gap. It was shorted internally. New plug and it ran great. What had thrown me off was that the plug had only been in the engine about a month. I'll never buy another Prestolite sparkplug. Anyway, I'd try a new plug before I removed the flywheel.
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Welcome to the site Wayne. The guy are right if you have spark and have gas it's got be timing or bad plug. Good luck finding the problem. If it's not any of those thing keep asking the questions somebody will fugure it out here on this site for sure. Ken
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Sorry I can't give you any additonal suggestions but I want to welcome you to the site. I don't know if we have a way to accept foreign $$ for a dues payment. We would welcome you to the club as a full MEMBER anytime. Dan
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Thanks very much for the warm welcome. Well the motor is out now and the key is intact ,flywheel in the correct position ,so i guess the only thing left is to have the coil checked out as i fear the the spark might not be as strong under compression. As far as compression is concerned ,what should the cylinder pressure be ? whilst the motor is out i should probably freshen it up a little ,after all it is 31 yo. On another note can anybody shed some light on the wire that comes from the coil area that connects to what looks to be a strip of bakelite or some insulating material ,on mine the wire is not connected to anything i assume it connects to the ignition alas that is not connected either. thanks and cheers W
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Welcome Wayne. I should come winter with you as you enjoy summer when I blow snow. Your point gap should be .020 instead of .015. Not sure that would keep it from fireing, just from running good. Not sure how low of compression these ole briggs will run on, I have a 16hp that had 90lbs after not running for 4 years, should check it now as 4 years and many hours of hard work its pretty tired. With that wire diconnected, if its the one I'm thinking you mean, not sure how your getting any spark. Thinking it should be connectted to an insulated bolt through the back plate and a wire from there to the points.
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Like MPH said re-gap the points. I would also check the armature air gap and replace the plug. Try those few things as well as the compression test, being 31yrs old dos not really matter its the use and maintenance that counts, my 3112 has the origional (1968) motor and it is up around 120psi, i have also had motors that ran fine arount what MPH is getting on his 16hp. Another thing you could check is if there is alot of rust on the armature and flywheel you can lightly sand. good luck
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