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Hi all. I'm new to the forum.

Just a slight bit of history, I am usually the one answering these questions! I am well known in the old Mopar and diesel areas. So I have a pretty good idea what's going on. Supposed to anyway. I'm above average with mechanics, I do my own engines and transmissions, brakes, front ends, on and on.

I have a 40 year old 3KW generator which has a Tecumseh HS40 power plant. It was my Dads so it's kind of precious to me. It's serviced us well over the years, but has been replaced with larger units. I keep it around for small emergencies and want to use it on my car trailer. Several years ago it stopped running and has been dormant since. It's kicking my butt.

I have no spark. I replaced the coil and condenser, cleaned the points up real good. I will replace them when I get the new ones. Got my parts from Jacks. In the mean time I wanted to see if the spark issue was fixed. Nope! I've checked the air gap on the magnets, points are set at .020, (Several times), new plug and made sure the cam on the crank is opening and closing the points. I re-lubed the cam as well. I tested both the old and new condensers and they seem to test out fine. There are no faults in the wiring (Shorts). If I put a voltmeter on the plug wire, it will spike the meter. But still no spark. I even put an air ratchet on the flywheel and tried it. I also go brave and held the plug wire. Still nothing. There's no kill switch so that's out.

Any ideas? I'm too invested it to quit now.

Thanks in advance.
Steve

Are the magnets in the flywheel still good? I've heard they do go bad (loose their magnetism).

Jeff

.020 sounds a little wide for the points. The point setting also adjust the timing. Don't know about your engine but also some engines you can put the coil in up side down and they wouldn't run. You might also isolate the engine from the chassis by disconnecting the primary wire. Also make sure your points are making good contact, because just the oil from your fingers will effect them.

Have you checked the timing? These old tecumseh's must be set properly. Here is a manual that may help. Also check the resistance on the primary and secondary coils. Primary resistance should be between 15-20 ohms, secondary between 15000-17500 ohms. Finally, check to see if the spark plug wire is securely seated in the coil.

http://www.mymowerparts.com/pdf/Tec...P-4-CYCLE-L-HEAD-FLAT-HEAD-ENGINES-692509.pdf

reynoldston said:

.020 sounds a little wide for the points. The point setting also adjust the timing. Don't know about your engine but also some engines you can put the coil in up side down and they wouldn't run. You might also isolate the engine from the chassis by disconnecting the primary wire. Also make sure your points are making good contact, because just the oil from your fingers will effect them.

Click to expand...

Rivets said:

Have you checked the timing? These old tecumseh's must be set properly. Here is a manual that may help. Also check the resistance on the primary and secondary coils. Primary resistance should be between 15-20 ohms, secondary between 15000-17500 ohms. Finally, check to see if the spark plug wire is securely seated in the coil.

http://www.mymowerparts.com/pdf/Tec...P-4-CYCLE-L-HEAD-FLAT-HEAD-ENGINES-692509.pdf

Click to expand...

The link takes me to a blank page

This is an internal coil. it can go on only one way. Coil wire is integrated.

Still, I should be getting something from it. This is all but dead

I'll check all this out today and click you a pic. Thanks for the comeback

Ahh I see what's going on with the link to the manual. Never mind. I bad

OK Timing is right on as far as I can tell, Air gap appears to be correct as best as I can measure it, and the manual calls for .020 on the points. I washed the points with some Acetone and ran a point stone through them again, chased with a dollar bill to wipe them clean. Still nothing

Even with the timing off, I should at least get some spark.

And yes, magnets are good. I've checked and rechecked so many things I forgot what I did.

Maybe it's too simple. I'm missing something. LOL

I can make you a whole wiring harness, but I can't get this old dinosaur running. :laughing:

Don't know why the link does not open, works fine on my end. I know the type of magneto system you have and it must be timed. If you can't open the link, do a google search for Tecumseh L-head engine manual. You should find open online as they are out there. Try this site.

http://www.barrettsmallengine.com/manual/tecumsehlheadmanual.pdf

Rivets said:

Don't know why the link does not open, works fine on my end. I know the type of magneto system you have and it must be timed. If you can't open the link, do a google search for Tecumseh L-head engine manual. You should find open online as they are out there. Try this site.

http://www.barrettsmallengine.com/manual/tecumsehlheadmanual.pdf

Click to expand...

Yeah I acknowledged the link problem in my last post. I was being stupid. LOL

Take a look at my last post. I'm baffled now

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.

reynoldston said:

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.

Click to expand...

Yup Yup and Yup again.

I checked the timing today, Had to wing the TDC. Turns out the adjustment is all the way over. There is no more. But it looked to be with in spec. I tested the coil condenser both old and new. All are still good. The lack of spark was what started this nightmare.

Here's a killer. After reviewing my work, 10 times, I turned out the lights in the shop and spun the flywheel. I got one healthy snap and nothing after that. I took the flywheel off and cleaned the points one more time with a dollar bill. (An old mechanics trick) There was a little dirt on them, and frankly I am very surprised there was anything on them at all. My bad again.

In the process, I lost the crank key. Ugh. I hate it when that happens. I stuffed an allen wrench in there and locked it in and still nothing.

There has to be something going on in those points, It's all that left!

Off to the parts store now (Jacks). . . . I'll be back (Arnold :laughing

Merry Xmas

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.

Rivets said:

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.

Click to expand...

Yessir That's what I used today to check the timing. 68 to 70. I forget where I read the coil resistance, but it was in spec. Both coils read the same. I used the same ground wire. It's what made sense. Unfortunately, my fluhe won't give me the ohms across the primary side, it just shows zero resistance. The secondary was 20 something.

I'm pretty sure there is something going on in those points. The one side had a crater burned into it, which I scrapped out, but. . .

I saw one zap out of this so far, and it was a pretty good spark at that. But only one. Now that the keyway is lost, it will have to wait. Calling Jacks in the morning. He was out of points though

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.

Rivets said:

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.

Click to expand...

MMMMM Then I misunderstood what I read.

Not surprised. . . . I lost alot with my strokes a few years ago. The bigger stuff, diesels and gas jobs, I don't need manuals for. Just specs and tolerances.

My new found handicap frustrates me greatly. That's why I am here

Thank you I am so embarrassed

Rivets said:

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.

Click to expand...

You my have misunderstood me.

I have continuity on the coil, on both sides. Both coils are reading 19K. The manual said between 18 and 21K if I recall.

I ordered a new key and the points, will be here later this week.

News at 11

I putzed with this today. Checked and rechecked this that an the other.

I'm getting intermittent spark. That tells me the coil is good. I'm thinking the pit in the points is too much.

I found the key. It was right under my nose.

I hate being old

I went thru the same thing with a 5hp on a snowblower. I have had that apart so many times I thought I would wear out the bolts. I checked, cleaned with the dollar bill would get spark but only a couple pulls and then it would quit. I finally took the coil off, the inside of the cover was so dirty as was the inside of the coil case. I replaced the points, everything was spotless inside. Set the points at .020 and the air gap at .020 and I got a nice blue spark!!! YEA! Put everything back together and it fired right up and ran like new after a little carb ajd. I would check the wires that attach to the points, something must be shorting out. A bare spot on it or a crack in the plug wire. It is something simple that is causing your problems. Hope that helps

Dreamen said:

I went thru the same thing with a 5hp on a snowblower. I have had that apart so many times I thought I would wear out the bolts. I checked, cleaned with the dollar bill would get spark but only a couple pulls and then it would quit. I finally took the coil off, the inside of the cover was so dirty as was the inside of the coil case. I replaced the points, everything was spotless inside. Set the points at .020 and the air gap at .020 and I got a nice blue spark!!! YEA! Put everything back together and it fired right up and ran like new after a little carb ajd. I would check the wires that attach to the points, something must be shorting out. A bare spot on it or a crack in the plug wire. It is something simple that is causing your problems. Hope that helps

Click to expand...

Thanks man

It's a new coil and condenser. I cleaned all that stuff. Barely had any dirt or rust in there. Not saying it's not worthy of another look though.

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.

Squaring pitted points is difficult. Hope the condenser is the correct one. When timing try this. Set a small transistor radio down near the engine and SET IT ON A CONTINUOUS STATIC sound. When you rotate the engine the opening points will cause an audible "pop." This lets you concentrate on the timing mark. We used this method years ago. The "hall effect" is a good suggestion despite its unfamiliar name.

bertsmobile1 said:

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.

Click to expand...

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.

bertsmobile1 said:

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.

Click to expand...

reynoldston said:

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.

Click to expand...

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.

Rivets said:

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.

Click to expand...

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.

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

bertsmobile1 said:

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

Click to expand...

Thanks Mate

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

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.

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.

Rivets said:

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.

Click to expand...

reynoldston said:

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.

Click to expand...

bertsmobile1 said:

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.

Click to expand...

bertsmobile1 said:

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

Click to expand...

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

I got fuel, spark and compression.

Will not start