Lauson/Tecumseh Power

[Wild Bill 633 770]

FYI, Certified Products Corporation in Edgerton, WI looks like it has info for the Lauson/Tecumseh engines.

[Gasaholic 183]

Yep, they bought the brand, patents, and remaining parts inventory from Tecumseh when Tecumseh finally bit the dust. They had planned to continue production of snow engines , but ended up just selling re-branded Honda Clones from China - Like LCT engines (Liquid Combustion Technology) but CPC is now the "official" source for OEM Tecumseh/Lauson parts, last I ever knew of. (Matter of fact they sued and won vs Oregon Outdoor because Oregon was selling essentially rebranded Tecumseh O.E. carburetors.. something to do with patents that had not yet expired, I believe.) 

 

We also have a nice source of engine repair info over at ppeten.com , a forum I started years ago when I was still in business. Forum is still going strong, but focusing mainly on Small Engines, and it was relatively rare to see Wheel Horse posts over there. KE4AVB whom is now pretty much running the place, maintains a vast stash of repair manuals and info, not all publicly accessible, but if one were to ask, he probably has engine (2-stroke & 4-stroke) repair manuals and data in his stash he can link you to for free download... There is also a conversion chart for Tecumseh carburetor ID numbers (stamped on the body) to Tecumseh Part numbers (For parts ordering & lookup) among other stuff. I believe the downloads section is restricted access though, if I remember right, had to have minimum number of posts and participation before forum "unlocked" and became visible. That was set up back when the site had very limited bandwidth per month - SEO & site scraper robots would constantly hit & download the manuals and burn up our monthly bandwidth, so... 

 

I have actually been considering selling off the site & domain if I could ever find someone that wanted to take over (and figure out how to convert that phpBB2 patched-up mess to a new forum... I no longer want to invest the money into it that I used to... Mostly survives as members still will donate some small bits plus the google ad revenue, so I barely break even.)

 

[ebinmaine 63,275]

Interesting this subject would come up because I'm going to be looking for an oversized piston and rings etc for an HH60 

[Pullstart 59,828]

3 hours ago, Gasaholic said:

Matter of fact they sued and won vs Oregon Outdoor because Oregon was selling essentially rebranded Tecumseh O.E. carburetors..

Sorry, but why would anyone want another Tecky carb?    

 

 

[pfrederi 17,168]

Because when they work they work well. The HH70 on my L107 has been running for 25+ years now.  Never cleaned it just dropped the bowl a few years ago and she starts quicker than most all of the Kohlers winter and summer.

[John2189 407]

What about the ignition coil? I have a 10 hp the coil went bad. I did the Ford rear wheel sensor and the chevy hei   It runs, but it backfires like crazy when over 1/2 throttle. I have a sicle mower on it so I don’t need to run it that fast. 

[Gasaholic 183]

Depends on the coil - There were some Tecumsehs made with electronic ignition that triggered off flywheel pins , there was one guy making & selling replacement kits for those using automotive components - the points ignition coils as far as I know are still available in aftermarket... as well as the external magneto electronic ignition (they triggered off flywheel magnets like Briggs engines) which last I knew of also were still in aftermarket sources (34443D if I remember right) 

 

 If your home-made ignition is backfiring at faster speeds, but seems to run fine at slower speeds means you have your timing retarded too far (too close to TDC, so when firing at faster speeds, spark is happening too late, unburned fuel in exhaust is what is backfiring... Backfire out the intake is usually a valve problem, 'cause valve should be closed well before firing happens... of course, if you have unburned fuel due to backpressure it can also fire when it comes up on TDC of exhaust stroke as intake starts to open and exhaust is closing, which can also be made worse by late ignition (retarded) timing. )  That's why some engines had a spark advance mechanism (electronic spark advance was built in to many modules) - so igntion firing would start earlier at higher speeds to get spark to happen still at the right spot and charge burning just as piston was starting down on power stroke to maximize power produced. 

[ebinmaine 63,275]

4 hours ago, Gasaholic said:

there was one guy making & selling replacement kits for those using automotive components

 

@John2189

 

There's a fella named @Ed Stoller who's done them. 

Ed has a bunch of videos on YouTube about how to build or adapt. 

 

 

Others too. 

@Pullstart or @squonk do you remember the name of the company that was selling the complete kits?

 

 

[John2189 407]

4 hours ago, Gasaholic said:

Depends on the coil - There were some Tecumsehs made with electronic ignition that triggered off flywheel pins , there was one guy making & selling replacement kits for those using automotive components - the points ignition coils as far as I know are still available in aftermarket... as well as the external magneto electronic ignition (they triggered off flywheel magnets like Briggs engines) which last I knew of also were still in aftermarket sources (34443D if I remember right) 

 

 If your home-made ignition is backfiring at faster speeds, but seems to run fine at slower speeds means you have your timing retarded too far (too close to TDC, so when firing at faster speeds, spark is happening too late, unburned fuel in exhaust is what is backfiring... Backfire out the intake is usually a valve problem, 'cause valve should be closed well before firing happens... of course, if you have unburned fuel due to backpressure it can also fire when it comes up on TDC of exhaust stroke as intake starts to open and exhaust is closing, which can also be made worse by late ignition (retarded) timing. )  That's why some engines had a spark advance mechanism (electronic spark advance was built in to many modules) - so igntion firing would start earlier at higher speeds to get spark to happen still at the right spot and charge burning just as piston was starting down on power stroke to maximize power produced. 

Its the electronic ign. I made the mounting bracket for the sensor off of the measurement from the original coil. I slotted the holes a bit to adjust air gap for the pins. Looks like I need to slot the holes so I can adjust the timing too. I guess I have to move the sensor so it sees the pin a bit sooner?

[Gasaholic 183]

14 minutes ago, John2189 said:

Its the electronic ign. I made the mounting bracket for the sensor off of the measurement from the original coil. I slotted the holes a bit to adjust air gap for the pins. Looks like I need to slot the holes so I can adjust the timing too. I guess I have to move the sensor so it sees the pin a bit sooner?

Depends,  You also need to know if it is a leading trigger or trailing trigger for the module - Leading trigger fires as soon as it detects the induced voltage hitting the trigger threshold, trailing trigger fires when the voltage drops BELOW the trigger threshold. Difference can be a few degrees of rotation. 

With an analog signal - a sine wave - I would expect it to be a leading trigger , a digital signal (Usually also needs a voltage source to it so it sees it as EITHER off or on -  a square wave) - could go either way. All really depends on knowing what the trigger for module is, and providing it a correct expected signal...

So I might expect if your set up is working at lower speeds, making it adjustable for timing would likely help get it dialed in.. so I'd want to adjust it more towards the opposite direction of rotation (advancing the timing)   

 

There's a bit of science (but not rocket science) behind it, but being aware that the old electronic ignition likely also had timing advance circuitry & control logic would probably help - if you can't electronically advance the timing, you'd have to trade-off with a bit more difficult starting (might even have to set it to where it might sometimes kick back when cranking if battery voltage drops too low or amps have to crank up higher to get it to a good cranking speed.... or tighten up valve clearances to reduce compression during cranking - a form of compression release, without a compression release mechanism) and possibly have to deal with backfire still at higher RPM's. Without being able to advance or retard timing dynamically as the engine is running, it is possible the engine may never run at top performance. 

[John2189 407]

4 minutes ago, Gasaholic said:

Depends,  You also need to know if it is a leading trigger or trailing trigger for the module - Leading trigger fires as soon as it detects the induced voltage hitting the trigger threshold, trailing trigger fires when the voltage drops BELOW the trigger threshold. Difference can be a few degrees of rotation. 

With an analog signal - a sine wave - I would expect it to be a leading trigger , a digital signal (Usually also needs a voltage source to it so it sees it as EITHER off or on -  a square wave) - could go either way. All really depends on knowing what the trigger for module is, and providing it a correct expected signal...

So I might expect if your set up is working at lower speeds, making it adjustable for timing would likely help get it dialed in.. so I'd want to adjust it more towards the opposite direction of rotation (advancing the timing)   

 

There's a bit of science (but not rocket science) behind it, but being aware that the old electronic ignition likely also had timing advance circuitry & control logic would probably help - if you can't electronically advance the timing, you'd have to trade-off with a bit more difficult starting (might even have to set it to where it might sometimes kick back when cranking if battery voltage drops too low or amps have to crank up higher to get it to a good cranking speed.... or tighten up valve clearances to reduce compression during cranking - a form of compression release, without a compression release mechanism) and possibly have to deal with backfire still at higher RPM's. Without being able to advance or retard timing dynamically as the engine is running, it is possible the engine may never run at top performance. 

Wow. Thats a bit over my head   I think I will leave it as it is for right now since it starts easy and it does what I need it to do. 
Thanks for the info. I will save this incase I do decide to change it. 

[ebinmaine 63,275]

18 minutes ago, John2189 said:

Wow. Thats a bit over my head   I think I will leave it as it is for right now since it starts easy and it does what I need it to do. 
Thanks for the info. I will save this incase I do decide to change it. 

It's one of those things that's more complicated to explain than it really is in practice.  

 

Watch Ed Stoller's Videos and you'll have a better understanding of the system(s) at play here. 

 

It's certainly a decent idea to figure out why an engine is backfiring. 

[John2189 407]

35 minutes ago, ebinmaine said:

It's one of those things that's more complicated to explain than it really is in practice.  

 

Watch Ed Stoller's Videos and you'll have a better understanding of the system(s) at play here. 

 

It's certainly a decent idea to figure out why an engine is backfiring. 

Yes it is thanks 

really im no dummy, I’ve worked on lawn mowers since I was probably 10 or so. Then cars, then fork lifts at work, then D8 and 9 cat dozers. Terex two stoke diesels and many more