HS40 No Spark Kicken my butt

reynoldston

Lawn Pro
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While this might just be making your problems worse please consider bypassing the points all together and fit a hall effect electronic trigger.
You used to be able to get a unit called "Atom" and they published what the timing & advance on each of their units was but when the patient ran out they abonded the market as every engine maker started to fit them as standard once they did not have to pay royalties.
Almost every old mower shop will have a stack of the old units and working pull form old engines.
Ask for one from an engine of around the same cc as your tecumseh.
Most should be OK, just do not use one from a two stroke.
They are not much more expensive than a set of points & condenser and will work happily for the next 50 years.
you fit them to the wire that goes from the points to the coil so you can rig it such that you can revert to points if it does not work.

This post has a very good suggestion. Very trouble free system and they go forever. The last time I needed a set of B&S points I couldn't find them locally and had to buy them over the internet.
 

Polaraco

Active Member
Joined
Dec 14, 2014
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68
While this might just be making your problems worse please consider bypassing the points all together and fit a hall effect electronic trigger.
You used to be able to get a unit called "Atom" and they published what the timing & advance on each of their units was but when the patient ran out they abonded the market as every engine maker started to fit them as standard once they did not have to pay royalties.
Almost every old mower shop will have a stack of the old units and working pull form old engines.
Ask for one from an engine of around the same cc as your tecumseh.
Most should be OK, just do not use one from a two stroke.
They are not much more expensive than a set of points & condenser and will work happily for the next 50 years.
you fit them to the wire that goes from the points to the coil so you can rig it such that you can revert to points if it does not work.

This post has a very good suggestion. Very trouble free system and they go forever. The last time I needed a set of B&S points I couldn't find them locally and had to buy them over the internet.

Agreed. But he doesn't live in the Metro area. Used mowers? Not the 2 shops around here. And nobody stocks parts any more. There is one dealer not far from who thinks a 20 year old rock chopper is made of gold, and the other won't sell them because of liability.
 

Polaraco

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Dec 14, 2014
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You just found your problem. 0 ohms across the primary means it iis shorted to ground. Secondary should be around 15,000. The readings you got are not in specs. Bad coil.

By the way, on my HS40, I am thinking the cam on the points is worn down too much to get proper timing. The crank point cam lube was dried out. Initially, the points were barely opening.
 

bertsmobile1

Lawn Royalty
Joined
Nov 29, 2014
Threads
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24,995
No problems.
Universal Ignition Parts - MEGA FIRE IGNITION
This will do the job good enough.
K&T Parts House - Briggs & Stratton Engine Parts - Ignition Batteries, Points, Condensers, Coils, Solenoids, Switches, Relays, Regulators, Fuses, Battery Cables&terminals, Wire, Battery Hold Downs - Electronic Transistorized Ignition
Another one and 1/2 the price of the previous.
There are better ones out there as universal means works every thing equally as bad, but at least it wil work.
Put an eye terminal on the module so you can bolt it to the old points wire & wrap it in insulation so if it all goes wrong you can undo it and go back to points.
yes points cams do wear but provided you can rotate the points plate enough to get it timed correct the amount of points gap on a flywheel magneto is not important as all the points do is close the circuit to earth and you do not have to allow enough time for a battery to saturate the coil.
DO not mount the module under the fly wheel it needs to get some air flow around it.
One of the "spare" holes in the control plate is a good place & easily accessible .
Don't hang the module or it will snap off they need to be bolted onto some thing.
I have some Briggs "Upgrade kits" in the shop some where, if I can find them I will post the B & S number but the rate Briggs change their part numbers I doubt it will be any use
 

Polaraco

Active Member
Joined
Dec 14, 2014
Threads
4
Messages
68
No problems.
Universal Ignition Parts - MEGA FIRE IGNITION
This will do the job good enough.
K&T Parts House - Briggs & Stratton Engine Parts - Ignition Batteries, Points, Condensers, Coils, Solenoids, Switches, Relays, Regulators, Fuses, Battery Cables&terminals, Wire, Battery Hold Downs - Electronic Transistorized Ignition
Another one and 1/2 the price of the previous.
There are better ones out there as universal means works every thing equally as bad, but at least it wil work.
Put an eye terminal on the module so you can bolt it to the old points wire & wrap it in insulation so if it all goes wrong you can undo it and go back to points.
yes points cams do wear but provided you can rotate the points plate enough to get it timed correct the amount of points gap on a flywheel magneto is not important as all the points do is close the circuit to earth and you do not have to allow enough time for a battery to saturate the coil.
DO not mount the module under the fly wheel it needs to get some air flow around it.
One of the "spare" holes in the control plate is a good place & easily accessible .
Don't hang the module or it will snap off they need to be bolted onto some thing.
I have some Briggs "Upgrade kits" in the shop some where, if I can find them I will post the B & S number but the rate Briggs change their part numbers I doubt it will be any use

Thanks Mate

I'll have the points here tomorrow. This maching isn't used enough to warrant all that.
 

Polaraco

Active Member
Joined
Dec 14, 2014
Threads
4
Messages
68
I've come to the conclusion these points are too far gone and are the problem. But the spark is more frequent and when it does snap, it's a nice hot spark.

I'll see if I can snap a pic of the condition of them. Worse than I thought. My eye site is not that great so I got out the shop magnifier. Even though I cleaned them and had a younger set of eyes helping me, they're still pretty bad. Badly pitted in the center, I scraped out the gouge on one side which gave me the intermittent spark.

In a automotive system, I could get away with it to finish the trouble shooting.
 

Polaraco

Active Member
Joined
Dec 14, 2014
Threads
4
Messages
68
You guys have been great. Thank you

I was always under the impression a coil was good or bad like a condenser. Apparently not.

While both coils tested good with a multimeter, the new one I purchased seems to be intermittent. I never saw that before. I didn't want to believe it either.

I remember commenting I was getting an intermittent spark and a few things were mentioned that were done already or checked. I was blaming the points because they had a crater burned into the center of them. I had time to putz today so I pulled the points out and filled the surface smooth. Pretty tough to do and keep them flat. I realized the pivot of the point set was stiff so I re-lubed the pivot point on the point set. Still only an occasional snap. I put the original coil back in and now I have a blue spark every time. ******Loud sigh******

If I wasn't so darned fat, I'd kick myself.
 

Polaraco

Active Member
Joined
Dec 14, 2014
Threads
4
Messages
68
Most of the time I totally agree with reynoldston, but this time I disagree on one of his posts. The magneto you have has three wires as he said, but both the primary and secondary coils are connected to the same ground. Did you test each of these coils for resistance? You can test each by going to the same ground wire coming off the coil. Are they within specs? Setting point gap and air gap are needed, but with this system you must also set when the points are going to open in relationship to piston location BTDC. With this engine the points should start to open at .035" BTDC. I understand that in 99 percent of the time this has not effect on the spark, but in this case you have tried everything else. The procedure for doing this is in the manual pages 68-70.

Very simple system. Coil with three wires. primary, secondary, and ground. Primary has no grounds to it? Secondary wire to the spark plug which is in good shape, ground wire to the ground. Coil in good shape and not grounded out to the coil legs, Points and condenser good to go. The only thing that sets the timing is point gap and coil air gap. Magnet are good. Just try to set the points a little closer and make sure you have good continuity through the points. It a new one on me seeing I never ran across that problem and I have worked on that system many time but also had to recheck my work to get spark some times.

While this might just be making your problems worse please consider bypassing the points all together and fit a hall effect electronic trigger.
You used to be able to get a unit called "Atom" and they published what the timing & advance on each of their units was but when the patient ran out they abonded the market as every engine maker started to fit them as standard once they did not have to pay royalties.
Almost every old mower shop will have a stack of the old units and working pull form old engines.
Ask for one from an engine of around the same cc as your tecumseh.
Most should be OK, just do not use one from a two stroke.
They are not much more expensive than a set of points & condenser and will work happily for the next 50 years.
you fit them to the wire that goes from the points to the coil so you can rig it such that you can revert to points if it does not work.

No problems.
Universal Ignition Parts - MEGA FIRE IGNITION
This will do the job good enough.
K&T Parts House - Briggs & Stratton Engine Parts - Ignition Batteries, Points, Condensers, Coils, Solenoids, Switches, Relays, Regulators, Fuses, Battery Cables&terminals, Wire, Battery Hold Downs - Electronic Transistorized Ignition
Another one and 1/2 the price of the previous.
There are better ones out there as universal means works every thing equally as bad, but at least it wil work.
Put an eye terminal on the module so you can bolt it to the old points wire & wrap it in insulation so if it all goes wrong you can undo it and go back to points.
yes points cams do wear but provided you can rotate the points plate enough to get it timed correct the amount of points gap on a flywheel magneto is not important as all the points do is close the circuit to earth and you do not have to allow enough time for a battery to saturate the coil.
DO not mount the module under the fly wheel it needs to get some air flow around it.
One of the "spare" holes in the control plate is a good place & easily accessible .
Don't hang the module or it will snap off they need to be bolted onto some thing.
I have some Briggs "Upgrade kits" in the shop some where, if I can find them I will post the B & S number but the rate Briggs change their part numbers I doubt it will be any use

HS40-55479E

You guys have been great and I thank you. I know how difficult this is when you can't see it yourself. I do it all the time on other peoples descriptions. I noticed they are much better here than they are on my diesel forum. Even at that, I shoot a 80% success rate.

Back to my nightmare. . . .

I got the points and a replacement coil. Put it all in and back together, no spark at all. WAIT A MINUTE! I HAD SPARK WHEN I TOOK IT APART! GRRRRRRRRRRRR

Put the old coil back in and snap snap. I've concluded the after market coils will not work in this machine.

I tried to take a compression test, but not doing well. I don't feel any compression with the finger and it's not moving my gauge at all. It has vacuum though. Now what? I'll check the intake valve to see if it's stuck
 
Last edited:

Polaraco

Active Member
Joined
Dec 14, 2014
Threads
4
Messages
68
I got fuel, spark and compression.

Will not start
 
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