Murphy's Law strikes again :-(

[MisterB]

It's snowing today and as luck would have it - my tractor won't start again :( Two weeks ago I replaced: Spark plug Points Condenser Battery Battery cables Those of you who may have seen my previous post will know that I considered a breakerless ignition replacement module and I in fact ordered one from Jacks' in the event I had trouble again. Now that it won't start (again) I decided to go ahead and swap the points/cond with this module. To my suprise, it still won't start... I've tested for spark and it seems to be OK. The instuctions that came with the "mega-fire II" are sparse to say the least. I simply removed the wire that was going to the points and connected it to the proper terminal (for neg ground system). I have one question remaining. Attached to the outside of the points cover is a small metal bracket with two wires attached. What are these for and could they be the source of my problem?

[Ronald Hribar]

I do not know what wires are for. But your Briggs should start with out any wire hooked to engine. The wire that does go to engine is just to shut engine OFF. so just leave wires hooked up to starter/generator or if you have just starter just to that. Then you should be able to turn motor over and the flywheel should supply the power thru the points to the spark plug Clear as mud??

[RayS]

Make sure the ignition module is grounded good they will give you problems if they are not. There should be two wires that come out of the shroud from the magneto. One goes to the points and the other goes to the bracket on the points cover and there will be another wire that comes from the ignition switch to the bracket on the points cover. They kill the engine.

[MisterB]

I believe the bracket that is attached to the points cover might have something to so with this. How does this work? [img]/club2/attach/RayS/img0043 Copy.jpg[/img]

[dhardin]

Gee your taxing my brain to much now. If i remember right that should be a peace of bakeolite (nonconductive) that is usually on the top screw of the points cover. The switch wire gose to this as well as the wire from the points/coil. As Ray said there is 1 or 2 wires coming from the coil, I think they both from the same terminal on the coil. Basicly its the ground/kill treminal. And yes it could well be your problemo. If thats a peace of metal and it was attached to the points cover it will never start. If its a peace of broke bakeolite and it looks to be, it has fallin down off its mounting and grounding out the points/coil just as if the key was turned off. Or this is where up put the electronic modual. But you will not need the wire to go the points ever again. It sould wire: small black wire from coil and black wire from key switch go the the blue or colored (Plus) wire of the electronic modual. And the white wire from the modual (ground) go the the top screw on the the points cover ground the modual and also inableling the kill switch to work.

[Boney]

I know I am jumping in here half way but have you checked if it is getting fuel ?

[RayS]

It will all fit under the points cover. I remove the condesor and mount it in the hole that the condensor goes into. Leave the points in there they leave pressure on the points plunger. If that bakeolite piece is broke you can make another piece from plastic and I believe they are still available thru Briggs. I ground one of the wires to the top screw that holds the points in place and the other is hooked to the primary lead wire going to the magneto.

[Wishin2BMowin]

You say it's getting spark so why worry about the wires? I'm with Boney on the "is it getting fuel?". These engines have an updraft carburator and need lots of choke to get the fuel in the cylinder. Have you tried taking the air filter off and spray some starting fluid in the carb? If so and it still didn't start, you may have some stuck valves or other issues?? Another thing to check is what weight oil are you running in the engine? 30 weight will get so thick that the engine won't turn over fast enough to start (trust me I found this the hard way) if so change the oil to a multi grade like a 10W30 for the winter... Best of luck...

[MisterB]

What purpose does that little bakolite bracket serve? Is there a reason I can't simply connect the two wires together using a butt-splice and heat shrink tubing? When I installed the mega-fire II, I removed the points (carefully in case I needed to put them back) and condenser. I used the hole that the condenser had been screwed into to mount the unit and I put the ground underneath the unit itself. I'm getting a better spark now than I had before and I can smell the gas - but it still doesn't fire up.

[RayS]

The bakolite is a insulator. Connect them together it will work as long as it is taped up good. The insulator is only $1.25.

[GWGAllisfan]

I made an insulator out of a piece of a pail lid. It's only there to allow for an easier engine installation. If you have gas and fire, have you checked compression?

[MisterB]

I put insulated spade connectors on each wire and plugged them directly together. I'll get another insulator next time I'm at the parts counter. ;) I pulled the plug and cranked the engine a few times. I can definitely see at least one valve moving up and down. Compression seems to be as good as one can expect from a 28 year old engine that's never been rebuilt (to the best of my knowledge). While cranking it a few times I got one heck of a backfire out the muffler!! I'd say it's getting fuel and some spark...

[msiebern]

quote:

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Originally posted by MisterB
I While cranking it a few times I got one heck of a backfire out the muffler!! I'd say it's getting fuel and some spark...

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Could this indicate a sheared flywheel key, causing the timing to be off? Also, check vavle adjustment.

[MisterB]

I've wondered how these engines were 'timed'. [:0] In a battery ignition setup, does the flywheel still control the timing?

[Roy]

No. the points, working off the cam or crankshaft depending upon the engine, control the timing.

[Brucep]

I agree with most everyone who has given some input here on the wires, insulator, spark and fuel and with all I have heard a sheared key may be a good thing to look at. I didn't catch the model or any thing so I'm not sure if you have to pull the engine to pull the flywheel. Not that I would know if I did know the model. If you have an armature than I believe the timeing can be off a little even if you didn't shear a key. I know on my old 10 horse briggs I was able to move the armature "bracket" a little to the left or right by loosening the bracket screws. I have never heard of it happening but I guess the screws could come loose and the bracket move on it's own. As far as compression I kind of think if you had a stuck valve you would be able to tell when you rolled the engine over. I know when pull starting an engine that I have pulled and heard several times I can tell when I have a compression lose, on electric start I would think maybe you could tell if it's rolling faster than normal. It's possible when you talk about compression that you could have lost a valve spring retainer or, on some engines, not sure on yours there are valve seat inserts. I have seen one come loose and hold the exhaust valve open. The insert I dealt with was held in by just peening it around the edges. I'm no pro mind you. Just some of my experiences.

[Morris]

One thing to check is the proper spark plug...you stated you were getting spark, but did you actually check the plug itself or just the plug wire. We all like to assume the plug fires if it we can get the plug wire to arc to a metal part, but it isn't always true. Spark plugs have specific resistances and heat ranges, and these values differ from engine to engine. Found that out the hard way when I put the wrong plug in my tiller once. Wouldn't fire at all! Just a thought. And of course, proper gap is essential as well.

[MisterB]

quote:

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Originally posted by Roy
No. the points, working off the cam or crankshaft depending upon the engine, control the timing.

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So, if there is a question regarding the flywheel position as a result of a misaligned key - could I get around the problem by converting from the magneto to a battery ignition? I'd think there would be other advantages to this as well, perhaps easier starting...

[msiebern]

While scouring the archives I came across this discussion that might clear up a lot of questions in this thread concerning spark and timing. Give it a read and I think things will get much clearer. http://www.simpletractors.com/club2/portal_External.asp?LinkID=121&LinkName=Replacing%20Points%20and%20Condenser%20with%20Electronic%20Trigger&CatID=20&CatTitle=Briggs&URL=http://www.simpletractors.com/club2/topic.asp?ARCHIVE=true&TOPIC_ID=19358%20

[fredwood]

Just a point of interest. It is not a good idea to use starting fluid on these small engines.Instead,I use carb cleaner. It is not as likely to cause damage,by too large an explosion,as starting fluid. Again just my point of view. Fred Wood

[Mick14]

I know i'm jumping in at the end of this ,,but i have to agree with Morris,,Are you sure you have the right plug ? a few years ago my local shop sold me a Bosch plug,,the coil out put on my little Briggs just wasn't enough,but it was to get a Champion to "go",I've also been warned about using ether in these engines,as fredwood said,could do a lot of damage.

[comet66]

I use WD-40 instead of starting fluid, it also adds a little lube to the cylinder walls, Which I think is a little easier on a cold dry engine.