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8HP Briggs No Spark


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05-09-17, 05:16 AM   #1  
8HP Briggs No Spark

I have an old rototiller with a vertical 8HP Briggs and Stratton 190402. I have absolutely no spark. I've replaced the plug, replaced the magneto, and set the correct gap. What is the next thing I should check to explain the no spark? TIA

 
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05-09-17, 05:26 AM   #2  
Posted By: BigBear1217 ". . . set the correct gap . . ."
Was that the Spark Plug Gap . . . . or the Point Gap ?

How old is the Condensor ?

 
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05-09-17, 05:44 AM   #3  
I assume with the new magneto you also got a new spark plug wire? Do you have a kill or on/off switch on the engine? If so check to make sure the coil kill wire isn't being grounded out.

Is the magnet still in the flywheel? Does the magnet seem strong?

 
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05-09-17, 06:42 AM   #4  
Vermont, I was referring to the magneto gap. I can't even get a spark to show when I'm holding the wire close to the plug.

Pilot Dane, yes I got a new spark plug wire. As far as I know, the only way to shut off the engine is by choking it out and shutting off the fuel. The magnet is still there and it does seem strong. I used the magnet to pull the magneto down on the gap cards.

 
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05-09-17, 07:10 AM   #5  
According to the B&S IPL that engine has points and condenser, they probably need to be replaced. Have a good one. Geo

 
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05-09-17, 07:23 AM   #6  
Posted By: BigBear1217 ". . . I was referring to the magneto gap . . ."
So . . . . there are three (3) gaps !

Does your engine have a Solid State ignition system, or the traditional Points and Condensor ?

When I pull up a B&S 190402 Schematic; it's a "horizontal" crankshaft engine.

 
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05-09-17, 08:29 AM   #7  
I have the points and condenser system down behind the flywheel.

 
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05-09-17, 11:27 AM   #8  
If you replaced the magneto as stated in your first post, I would imagine that it is solid state and the points need to be eliminated.
As far as I remember, you simply replace the mag, then cut the wire going to the points, no need to remove them. You may have to rig something up for the kill wire, or you might be able to eliminate it also as your engine may have or had, a spring steel flat bar bolted to the head that would hang over the spark plug, you simply contact the steel to the top of the plug and hold until the engine is off.


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05-09-17, 12:37 PM   #9  
The wire that goes down behind the flywheel from the magneto is attached under a spring. The spark plug sticks out of the top of the block and there isn't anywhere where a piece of steel would have been.

 
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05-09-17, 12:42 PM   #10  
My specific model number is 190402-0652-99.
Name:  190402-0652-99_WW_1.jpg
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05-09-17, 03:01 PM   #11  
That sure looks like it's a Horizontal Crankshaft !

 
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05-09-17, 03:29 PM   #12  
190402-0652 IPL

Shows that engine to be a horizontal shaft and the stop switch (# 347 on page 2) is one of three different spring steel used depending on which plug your specific type uses, but is just as I described and would be mounted underneath a head bolt.

Name:  StopSwitchBriggs.jpg
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If you have no stop switch, it has been removed, broken and or lost. Even machines as old as that did not come without some type of switch to cut the electrical circuit to the spark plug to shut the engine off.


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Last edited by BFHFixit; 05-09-17 at 03:58 PM.
 
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05-09-17, 04:06 PM   #13  
If you replaced the magneto, what part number did you replace it with?
298968 is the correct part number for your armature assembly, however, if you purchased it from any reputable dealer or service center, they likely had updated part number for a solid state assembly that requires the points to be eliminated from the circuit, just not from the engine.


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05-09-17, 06:01 PM   #14  
I apologize for the mistake on the crankshaft. The part I ordered was part number 298968 from ereplacements.com and have it installed. If this is the correct part, what should my next step be specifically? As you can already tell, I have almost no experience. Just trying to save myself some money and do some learning in the process.

 
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05-10-17, 04:00 PM   #15  
Unfortunately I am having little success finding information concerning converting your engine to the magnatron armature. Short of contacting Briggs myself to be certain, which you can and perhaps should do since you own the equipment and I am not servicing it.

I suspect that there is an issue with your points and or condensor, and the sure thing would be to replace them (part # 294628)

I was incorrect about the stop switch mounting under a head bolt. Just to the side of the spark plug should be a slot in the cooling fins. Above this the engine shroud will have a small tab, the steel fits in the slot and the tab in the shroud.

I did find some references to part # 398811 as a magnatron coil that is used on 7-16HP engines (is yours 8hp?) that may work for you as well, however, I found nothing definite.

I am surprised cheese has not chimed in as I am rather certain he has done a few of these upgrades. It has been so long since I have and not many at that, but as I recall it is just a matter of cutting the wire to the points, install the new mag and kill wire if equipped, which your engine should not have simply the stop switch I described.

According to your date code you engine should have been made in 1999. The problem converting to the magnatron system is mainly with engines made prior to 1981 as the flywheels had multiple magnets and not polarized correctly to afford the magnatron.

Best bet would be to contact Briggs They are knowledgeable and willing to help.

I am sure if I could put my hands on it I could find a solution...however, I apologize I can not find an exact solution letting my fingers do the walking


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05-10-17, 07:50 PM   #16  
Looks like what Geo said - you put in the point type coil and the points/condenser is the problem. You could replace the ignition with the module as BFH was talking about, but since you already have the coil you may want to pull the flywheel and put in a set of points/condenser.

The gaps you would have would be the points, coil air gap and the plug gap.

 
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05-11-17, 04:35 AM   #17  
I'll try to find out more info and come back if i have any more questions. Thanks everyone for the suggestions and advice. Hopefully I can get it running soon.

 
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05-11-17, 08:47 PM   #18  
Most of the time a new coil is available with the electronics already present to eliminate the points. If yours does not have that, you can install a magnetron module and be done with points/condenser problems forever.

http://www4.briggsandstratton.com/mi..._retro-fit.pdf


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