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18 hp briggs will not start


dkmorgen's Avatar
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07-31-06, 08:12 PM   #1  
18 hp briggs will not start

hi all, great forum you have here
so here it goes, i was mowing the other day, all was going fine
then my mower just quit while mowing with no warning @ all .
i started trouble shooting i am getting fuel but i am not getting
fire to either cylinder i checked for shorts in the plug wires none found then i unpluged the ground wire that goes to the coil to check if it was a switch or a short causing this turns over but still will not start, so i replace the coil with another spare that i have an still i will not start i am lost from there
it is a twin cylinder 18 hp briggs motor model 422707 type 1263-01

many thanx in advance

 
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07-31-06, 09:18 PM   #2  
If you replaced the coil and it still don't fire then replace the distributor.That will solve it.Is this a riding mower or push you do not say so im asuming rider.

Posted By: dkmorgen hi all, great forum you have here
so here it goes, i was mowing the other day, all was going fine
then my mower just quit while mowing with no warning @ all .
i started trouble shooting i am getting fuel but i am not getting
fire to either cylinder i checked for shorts in the plug wires none found then i unpluged the ground wire that goes to the coil to check if it was a switch or a short causing this turns over but still will not start, so i replace the coil with another spare that i have an still i will not start i am lost from there
it is a twin cylinder 18 hp briggs motor model 422707 type 1263-01

many thanx in advance

 
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07-31-06, 10:46 PM   #3  
Hello dkmorgen,

Did you set the air gap between the coil and the flywheel to .010"? Did you get the coil on right side up? (no offense, but it has to be asked. Lots of people get them on upside down). If yes to the above, then remove the kill wire from the coil and check for spark again. Are you letting the spark plug touch metal on the mower when checking for spark?

Lexmark567...distributor?? There are no distributors on ordinary lawn mowers. Have you ever seen an 18hp push mower?


"Who is John Galt?" - Ayn Rand (Atlas Shrugged)

God bless!

 
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07-31-06, 10:58 PM   #4  
Posted By: cheese Hello dkmorgen

Lexmark567...distributor?? There are no distributors on ordinary lawn mowers. Have you ever seen an 18hp push mower?
What about those lawnmowers the pro lawn companys use those things are big and LOUD.

 
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07-31-06, 11:07 PM   #5  
Nope. The only mowers with distributors are very big ones with car-type engines. And most of those are diesels, so no distributor there either.


"Who is John Galt?" - Ayn Rand (Atlas Shrugged)

God bless!

 
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08-01-06, 06:09 AM   #6  
yes it is a rider its a huskee about 6 years old
i did set the air gap on the coil to .015
an i did remove the switch wire from the coil
it turns over well but it will not fire at all
carb was rebuilt at the begining of mowing season
but i am getting fuel
as for letting the plug touch metal i used a wire with 2 alligator
clamps on it to ground with.
i did sand the edge of the coil to remove some rust
i am going to check that the fly wheel key hasn't sheared
will let you know shortly on that

thanx again dkmorgen

 
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08-01-06, 08:48 AM   #7  
You have yet to indicate if you have spark at the spark plugs. Do you? Are you sure, as Cheese indicated, that the coil is not on upside down? If this is a used coil, you may have a bad used coil. Be sure to set the clearance at .010". If all is correct and you still have no spark at the plugs then buy a new coil, Briggs part number 394891.

 
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08-01-06, 10:32 AM   #8  
fly wheel key is not sheared and yes the coil is right side up i forgot to mention that point,reset gap to .010
an still no fire at the plugs
i put spare coil back in a diffrent mower an it fired right up
so i am still lost on this one
thanx all for all of your input

 
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08-01-06, 04:21 PM   #9  
Like Cheese asked, are the plugs WELL grounded to the STEEL part of the engine. With the stop wire off the coil, a known good coil, (you said it ran on another mower) & good plugs & wires, This thing should start. re-check & let us know

 
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08-01-06, 06:04 PM   #10  
If all the answers to the questions in the previous posts are affirmative then you have two bad spark plugs and the chances of that is about 2,672,873,871:1. I guess I would buy a new coil however, they are not cheap. I think I paid $68 a year or so back for the same engine? One last thing that I can think of is an intermittent problem in the coil. That's all I can figure to explain it working on another mower? This sounds stupid but did you check the coil on a two cylinder engine? If so try this: Gap both plugs to .15 instead of .30. That 18 horse will run fine that way but I was advised against it. If it works that way it would tell you that your coil isn't producing sufficient voltage to spark both plugs. All that might be for naught as it only suggests that you need a new coil anyway? Good luck I'll be interested to learn how to solve this one.

 
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08-02-06, 06:15 PM   #11  
Guess what guys replaced fly wheel an now it fires right up
put that fly wheel on another mower an "well lets leave it at that"
thanx to all who had input on this one
you all are great about answering quickly
thanx again to all

 
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08-03-06, 09:17 PM   #12  
Strange. I don't think I've ever seen one that lost it's magnetism. Thanks for the update, and glad you got it fixed.


"Who is John Galt?" - Ayn Rand (Atlas Shrugged)

God bless!

 
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03-05-08, 02:45 PM   #13  
Deja Vue - Good Timing

I have an 18 HP riding lawn mower, 422707 type 1214. I am having the same exact problem. This mower had been sitting a while before I purchased it. The previous owner had robbed some parts off of it, other parts I robbed. I am now in the process of putting it back together to see if I can make run. I cleaned the carb and gas tank and replaced all fuel lines/filter.
New starter, new coil. Cranks over, spins nicely, no spark. NONE, nadda, zippo. <br>
My first question - does the coil get installed with the plug wire leads on top, or on the bottom ? I installed coil with leads on bottom because that makes most sense as it keeps them out of harms way, but let me know.
<br>
If the flywheel holds the magnet, how could a sheered-key cause it to fail to spark ? I could see that a sheered key would affect timing, but how it could stop/affect the system sparking, I don't grasp. If somebody could enlighten me....perhaps there is some voodoo going on that I am not aware.
<BR>
I disconnected the non-spark plug wire at the coil, but to no avail. I don't have rubber boots on the wires where the spark plug wire snaps onto the spark plug. I was manly and grabbed the bare end of the wire, I get nothing, not even a little tickle, darn it.
<BR>Is it truly possible that my magnets are so weak.... could it be that my brand new coil is - gasp - defective....
tune in next week for another exciting episode of ... "What's Wrong With That Guys Mower?" sub-episode - "The Spark Has Left His Life".

 
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03-05-08, 04:16 PM   #14  
Flip the coil over wires up then set coil to flywheel magnet air gap to 0.12", A sheared flywheel key will have nothing to do with making spark but will cause spark at the wrong time.

BTW, I'm not man enough to hold ANY spark plug wire

I have 5 different style spark testers.


Oh, It may benefit you to start a new thread of your own next time. Some just skip over old threads.

Good Luck

 
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03-06-08, 06:11 AM   #15  
While this topic is up though, it would be good to expand on the topic though.

On these small engines, the rotation of the flywheel past the
coil is what produces the spark, and failures of the flywheel
{losing magnetism} is almost none, possible, but I have never seen it.

Now every time the flywheel revolves, a spark should occur, unless the coil has failed, or the coil is grounded
through the "kill" wire, the small wire going into the base of
the lamination, so testing is relatively easy, just unplug that
wire. It is very rare to have a coil failure on a pushmower,
and the reason is, the majority of coil failure are due to stray
voltage reaching the coil via the "kill" wire, usually due
to frayed wiring or defective switches etc.
So it is very important to ensure that no voltage is being supplied at any time to the coil, as that will destroy it.
If you just replace a coil that was bad, and plug a new one
back into the bad wiring, and you just wasted another $50.

I have seen frayed wiring let 3-6 volts back into the kill
wire circuit, which over time will burn it up. So when testing
that wire for voltage, I jiggle all the wiring, with the keyswitch in all of the different positions, and move all of the mower's levers, etc.

Fish

 
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03-17-08, 06:46 PM   #16  
Coil Problems

Turns out that the coil that I purchased, has in raised lettering, " THIS SIDE OUT" Which means that was the side of the coil that should go up, i.e. visible. Which means the wires are under the coil and in order to route them to the spark plugs, makes an immediate U-turn towards the front of the motor.

I have installed the coil correctly this time. Unfortunately I have moved onto a more pressing project. Funny thing is, it doesn't have spark either.

No sooner than I posted than I thought I should have started a new thread, thing is, I found this thread via google, not this websites front door.

Ray

 
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