# Tecumseh silly question time



## milliesdad (Nov 13, 2013)

I have a Jacobsen Imperial 826 with no spark. Although I've turned wrenches on cars, trucks, Diesel locomotives, lawn mowers and motorcycles, I've never had to work on an old tecumseh.

I purchased a solid state coil for it and my question is will the solid state coil replace the entire magneto? I mean, pull off the flywheel (magneto is under the flywheel), drop the magneto assembly (points, condenser and coil) in the trash bin and screw in the solid state coil and reassemble.


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## e.fisher26 (Nov 6, 2016)

Did u match the new coil with the engine model or the model of the machine?


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## paulm12 (May 22, 2015)

need part numbers from the engine. If it is an internal ignition system (points/condensor module and coil all under the flywheel) then I am not aware of a solid state replacement. There are no external mounts on the engine casting for a replacement module. If it is external coil engine, with the points module still under the flywheel, and the coil module outside the flywheel, then there are some solid state replacements available.


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## milliesdad (Nov 13, 2013)

e.fisher26 said:


> Did u match the new coil with the engine model or the model of the machine?
> 
> 
> Sent from my iPhone using Tapatalk


Yes. And from what I saw, the coils from a 4HP up to 8HP are the same, as are the points and condenser.


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## milliesdad (Nov 13, 2013)

Thanks. This is what I thought would be. I'd never be lucky enough to have it simple. The entire ign system is under the flywheel and there are no mounts for an external coil.


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## paulm12 (May 22, 2015)

points and condensor are easy to replace. But timing check requires a dial indicator on the piston through the spark plug hole (there is a tool for that) or remove the head and use a machinist setup for the indicator.


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## cranman (Jan 23, 2016)

I've done quite a few points replacements on those old Tecumseh...and decided to scrap the engine in favor of a Predator from now on.....The only Tecumsehs I'll keep for myself must be electronic ignition. What I really like about those old flathead Briggs from the 60's and 70's is how easy it is to convert to a modern pointless magneto.


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## paulm12 (May 22, 2015)

cranman: was I correct in saying that the older Tecumseh engines without the external mounts for the coil cannot be converted to electronic ignition? Or is there a full electronic ignition module that can go inside the flywheel?


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## e.fisher26 (Nov 6, 2016)

milliesdad said:


> I have a Jacobsen Imperial 826 with no spark. Although I've turned wrenches on cars, trucks, Diesel locomotives, lawn mowers and motorcycles, I've never had to work on an old tecumseh.
> 
> 
> 
> I purchased a solid state coil for it and my question is will the solid state coil replace the entire magneto? I mean, pull off the flywheel (magneto is under the flywheel), drop the magneto assembly (points, condenser and coil) in the trash bin and screw in the solid state coil and reassemble.




What is the model of the engine?


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## cranman (Jan 23, 2016)

I've heard of a module to relpace the points on the old Tec's, but have no experience with them...


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## Sid (Jan 31, 2014)

I bought one a few years ago, installed it, and caused "kickback" and that hurts. Bought another unit with an anti kickback feature, and it works perfectly, been in use for 15 to 20 years.
Sid


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## ST1100A (Feb 7, 2015)

cranman said:


> I've heard of a module to relpace the points on the old Tec's, but have no experience with them...


The module is easy to install. Just disconnect the wire to the points and hook it up to the module.
Mount the module to an easily accessible place and ground the module. There are two wires for the module, one goes to the coil, one goes to ground, and then you don't have to worry about the points anymore.
You can just leave the points in the engine, but disconnect them from the wiring and hook up the wire to the module.
The module comes with instructions and is available from Stens.


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## milliesdad (Nov 13, 2013)

e.fisher26 said:


> What is the model of the engine?
> 
> 
> Sent from my iPhone using Tapatalk



It's HM80.


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## paulm12 (May 22, 2015)

I am still a bit confused. Is there an electronic ignition replacement for the points system on the earlier Tecumseh HM80's that have the points module and coil assembly mounted internal to the flywheel? Again, there are no mounts on the block casting, outside of the flywheel, for the coil, and to set the air gap timing. On the pic I have the points and condensor out to be replaced. My dealer chuckled a bit when I ordered them. 

See pics.

sorry for hijacking the thread, but it relates to the OP question


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## ST1100A (Feb 7, 2015)

paulm12 said:


> I am still a bit confused. Is there an electronic ignition replacement for the points system on the earlier Tecumseh HM80's that have the points module and coil assembly mounted internal to the flywheel? Again, there are no mounts on the block casting, outside of the flywheel, for the coil, and to set the air gap timing. On the pic I have the points and condensor out to be replaced. My dealer chuckled a bit when I ordered them.
> 
> See pics.
> 
> sorry for hijacking the thread, but it relates to the OP question


Yes, take the wire from the coil to the points and connect it to the module, not the points. Disconnect the wire at the points and splice it to the module with the wire and splice included in the kit.
Mount the small module where it is convenient, usually on the blower housing with the supplied sheet metal screw.
You don't have to remove the points, you just disconnect the wire from the coil going to the points and hook that wire to the module, and hook the ground wire from the module to a ground that is also included in the kit.
It is a very simple kit to install. You just re-route the coil wire to the module after you remove it from the points. The kit comes with a couple of different wires and connectors and splices, and has installation instructions included.
You don't have to take the points out if you don't want to, they are not being used anymore, but you can remove them just to get rid of them.
Your kill switch wire connects to the coil wire where it mounts to the ignition module, you just splice it together with the connector that attaches to the module.
The module has two posts, one goes to your ignition coil and the other wire goes to a ground, usually the screw that mounts the module to the blower housing or where ever you mount it fast to the engine. If you mount the module somewhere else, just make sure you mount the ground wire to the engine somewhere so it has a good engine ground.
I wire tied a module to a rubber fuel hose on one engine and it works fine, I connected the ground wire to the bolt that held the point cover to the engine.
The kit includes connectors, splices, like 4 different wires, some with terminals on them a sheet metal screw and the module and instructions. The module is about an inch square.
You can use the same kit on Briggs and tecumseh magneto ignition. They have a separate kit for battery powered ignitions.


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## paulm12 (May 22, 2015)

how is timing set in that situation? you can't set an air gap like on the external coil systems.


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## milliesdad (Nov 13, 2013)

ST1100A said:


> Yes, take the wire from the coil to the points and connect it to the module, not the points. Disconnect the wire at the points and splice it to the module with the wire and splice included in the kit.
> Mount the small module where it is convenient, usually on the blower housing with the supplied sheet metal screw.
> You don't have to remove the points, you just disconnect the wire from the coil going to the points and hook that wire to the module, and hook the ground wire from the module to a ground that is also included in the kit.
> It is a very simple kit to install. You just re-route the coil wire to the module after you remove it from the points. The kit comes with a couple of different wires and connectors and splices, and has installation instructions included.
> ...



Have you got a manufacturer name and part number to order? Where is the best place to order one?


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## enigma-2 (Feb 11, 2014)

milliesdad said:


> Have you got a manufacturer name and part number to order? Where is the best place to order one?


Heres one example:
https://www.jackssmallengines.com/j...mi0lma75vx1giv2aogch0dlwy9eaqyasabegl54pd_bwe


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## ST1100A (Feb 7, 2015)

enigma-2 said:


> Heres one example:
> https://www.jackssmallengines.com/j...mi0lma75vx1giv2aogch0dlwy9eaqyasabegl54pd_bwe


Yes, that looks like the one.
You can find them on EBay and a lot of other places.
Just make sure you get the one for magneto ignition, they also make them for battery ignition, so you want to look them up to make sure you order the right one.


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## ST1100A (Feb 7, 2015)

paulm12 said:


> how is timing set in that situation? you can't set an air gap like on the external coil systems.


You don't have to set anything or do any tuning, just hook it up and go. That's one of the nice things with it.
The only tuning you have to do is make sure your armature to flywheel air gap is correct for the ignition coil, that's all.
I've had ones in engines that are running good for a couple of year now, no more points to have to mess with and either re-gap,adjust or replace.


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## paulm12 (May 22, 2015)

ST1100A: sorry, but I am still missing something. I understand how to do this when the armature is mounted outside the flywheel. The air gap is the timing mechanism. But how do you set the air gap when the armature is mounted under the flywheel?


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## Grunt (Nov 11, 2013)

Here is the same NovaII module cheaper.
https://www.ebay.com/itm/ELECTRONIC...712820&hash=item3a66b36755:g:p00AAOSwWKtUvoIP


This is how it is connected to the OLD points wire.


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## ST1100A (Feb 7, 2015)

paulm12 said:


> ST1100A: sorry, but I am still missing something. I understand how to do this when the armature is mounted outside the flywheel. The air gap is the timing mechanism. But how do you set the air gap when the armature is mounted under the flywheel?


Tecumseh used to make a special tool for that, but good luck finding that tool.
Usually just install the module and don't mess with the armature coil, just re-install it. Use the markings of the mounting screws that made a mark on the coil when you took it off, you should see the spots the screws made on the coil where it mounted. Most of the time people just installed the module and never disturbed or removed the coil.
Tecumseh gave a wide variance for that gap. Usually when you mount everything back in place it will work fine for you.
The tool tecumseh made went over the crankshaft to use as a template to set the air gap, it gave you room to get a feeler gauge in to take your measurement and then you tightened up the coil mounting bolts. 
You couldn't adjust the coil that much the way the slots were in the coil, basically as long as the coil did not hit the flywheel when it was installed, you were ok. Tecumseh did things funny ways compared to Briggs.
There is a Youtube video about installing the module kit I saw one time.
When you first install it and spin the engine over to check for spark and you don't have spark, reverse the wires on the module, + to -, then check for spark, sometimes all you have to do is switch them.


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## enigma-2 (Feb 11, 2014)

paulm12 said:


> ST1100A: sorry, but I am still missing something. I understand how to do this when the armature is mounted outside the flywheel. The air gap is the timing mechanism. But how do you set the air gap when the armature is mounted under the flywheel?


https://youtu.be/i_mqMayLgnY


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## paulm12 (May 22, 2015)

I did read how to set the timing on these early Tecumseh points systems, and, surprisingly, DonnyBoy is very sloppy here. Timing is properly set with a dial indicator on the piston, rotating the module to get the open/close transition on the points to a specified BTDC distance. All of this before the flywheel is installed of course. What he showed will get timing close, but I will go through the proper procedure. 

I am concluding that these early Tecumseh engines do not have a full electronic ignition replacement, I have new points and condensor on order and will go through the points gap and timing procedure as specified by Tecumseh. 

Thanks all for the comments. And sorry again for hijacking the OP thread.


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## Grunt (Nov 11, 2013)

paulm12 said:


> I am concluding that these early Tecumseh engines do not have a full electronic ignition replacement,


No, there is no direct replacement coil. You would have needed a new flywheel with magnets on the outside and the coil stand offs molded into the engine block to make it work. Older Briggs had a Magnetron ? to replace the points on their older motors.


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## ST1100A (Feb 7, 2015)

No the old tecumseh did not have electronic ignition, like Grunt stated.
The old Briggs, You could either replace the coil with the Magnetron set-up, or use the module kit.
Some of the old Briggs had to have the flywheel "Re-Polarized" to use the Magnatron coil, that was usually on the cast iron 16 H.P. engine. In that case it was easier to install the module kit.
Paulm sent a link to a good video about timing the tecumseh engine. There isn't too many of those older tecumseh engines around anymore, but they are still out there running, just harder to get parts for them now.
They were great mini-bike and go-kart engines, they accelerated quick and you could lean them over far, but you would usually blow them up as fast as they ran, but they were a lot of fun back then and were not expensive to replace.


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## ST1100A (Feb 7, 2015)

Now if you were rebuilding that Tecumseh motor for an old Rupp Black Widow minibike, that is a different story with the timing advance settings. Those things were a very highly tuned up high revving engines with hotter cams and different carburetor with straight pipe exhaust. Those things used to be very fast running Mini-Bikes that are worth money today if they are in good shape and original, a lot of collectors are after them and the engines for them.


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