How to make Tecumseh engine burn better?

[jeepman3071]

There's a reason Tecumseh went out of business...their engines were J.U.N.K

Actually the reason is the other companies were able to outsource their stuff to China and cut costs quicker than Tecumseh. Back in the day Tecumseh made good engines, especially snow engines. They were known as the best, and their engines were actually better on fuel (lawn mower engines at least). Once ethanol fuel came out that really drove the last nail in the coffin as their carbs seemed to suffer the worst due to the design. Then the other manufacturers (Briggs and Kohler) moved stuff overseas so they could come in with cheaper contracts to the small engine manufacturers, and a few years later everything had Honda clones.

 

[wag123]

There were two primary reasons why Tecumseh went under...
1. They failed to design and produce 2-cylinder engines, basically handing the more profitable rider and larger equipment market to Briggs and Kohler.
2. They lost the retailer that was selling the majority of their engines for MANY years, Sears. For many decades when you went to Sears and purchased a Craftsman lawnmower it had a Tecumseh engine on it. For a long time Sears sold more lawnmowers than anyone else, by a wide margin.

 

[K.Aoi]

There were two primary reasons why Tecumseh went under...
1. They failed to design and produce 2-cylinder engines, basically handing the more profitable rider and larger equipment market to Briggs and Kohler.
2. They lost the retailer that was selling the majority of their engines for MANY years, Sears. For many decades when you went to Sears and purchased a Craftsman lawnmower it had a Tecumseh engine on it. For a long time Sears sold more lawnmowers than anyone else, by a wide margin.

Did they even make big enough singles for riding mowers? I can't remember seeing much above around 10HP or so.

 

[Zaedock]

If you could bottle that Tecumseh exhaust smell, I might start wearing cologne.

 

[wag123]

Did they even make big enough singles for riding mowers? I can't remember seeing much above around 10HP or so.

Yep, up to 18hp.

 

[Lubener]

For those who still believe Tecumseh's are junk.I couldn't make one stop on a mower where everything was shot except the old Tecumseh engine which I didn't want and was part of a load to the scrapper. It ran for 20 minutes with no oil. It ran out of gas first. They were good engines but economics led to their demise.

 

[Warlord]

I love my tecumseh powered equipment. They're extremely simple and reliable engines probably because they didn’t change much since they introduced their first engine.

 

[Cujet]

Project Farm has some really interesting You Tube videos with slow motion lawn mower carb atomization clearly shown.

All 4 stroke engines produce a strong standing wave pulse in the intake runner at certain RPM's, depending on factors like cam timing, cam overlap, intake runner length, volume and RPM. Engines that have one "carb" per cylinder are subject to some reversion (back flow) through the carb (that entrains a bit more fuel) and often produce a cloud of vapor sometimes called "stand off". You can clearly see it in the video below.

In the case of the engine in the video, they would be far better off to use a single large air filter box to contain the cloud of fuel vapor, as this controls the Air/Fuel mixture much more accurately.

Those old engines really do need the air filter assembly to be installed to contain this vapor.



But to answer your question directly, a more modern carb, if chosen correctly, will give a better result. But it will not offset the issues created by poor cam timing, poor intake valve sealing and obvious issues created by a very low compression ratio.

 

[racinjason]

There were two primary reasons why Tecumseh went under...
1. They failed to design and produce 2-cylinder engines, basically handing the more profitable rider and larger equipment market to Briggs and Kohler.
2. They lost the retailer that was selling the majority of their engines for MANY years, Sears. For many decades when you went to Sears and purchased a Craftsman lawnmower it had a Tecumseh engine on it. For a long time Sears sold more lawnmowers than anyone else, by a wide margin.

I have an mtd mower one time with a v-twin tecumseh on it. Engine was a beast. I think it was a 42 or 46” cut, the engine easily could have handled 54”.

I’ve seen other mowers with tecumseh v-twins on them. Several Stanley mowers(mtd made).

 

[racinjason]

Yep, up to 18hp.

I also had a 17hp single tecumseh one time, it too was on an mtd, 42” variator machine. Engine had plenty of torque. It didn’t bog down nearly like a Briggs. It cut more like a big single Kawasaki.

It seems they had a lot of coil trouble maybe??

 

[racinjason]

Top was what my v-twin looked like, bottom right was the single.



I avoid tecumseh in my flipping though. It’s mostly older now anyways.

 

[wag123]

I have an mtd mower one time with a v-twin tecumseh on it. Engine was a beast. I think it was a 42 or 46” cut, the engine easily could have handled 54”.

I’ve seen other mowers with tecumseh v-twins on them. Several Stanley mowers(mtd made).

Tecumseh did eventually produce V-Twin engines but they were very late to the game, Briggs and Kohler already pretty much owned the market by then, and they were already in serious financial trouble. You don't see many of them out there.

I also had a 17hp single tecumseh one time, it too was on an mtd, 42” variator machine. Engine had plenty of torque. It didn’t bog down nearly like a Briggs. It cut more like a big single Kawasaki.

It seems they had a lot of coil trouble maybe??

To my recollection, the only Tecumseh engines that commonly had ignition problems were the cast iron block singles.

 

[racinjason]

Tecumseh did eventually produce V-Twin engines but they were very late to the game, Briggs and Kohler already pretty much owned the market by then, and they were already in serious financial trouble. You don't see many of them out there.

To my recollection, the only Tecumseh engines that commonly had ignition problems were the cast iron block singles.

I do agree, they were very late to the game. I’m pretty sure this twin I had was made mid 2000’s.


I knew the old iron ones had coil problems, the 17 I had also ate more than one coil(second was aftermarket)

 

[andyd]

I have a vintage Ariens Sno Thro. Actually its a collection of good parts and a Predator. All my Tecumseh engines were worn out. For less than the parts to rebuild, I bought a brand new OHV engine for only 99.99$ That was 7 yrs ago and it has worked faultlessly ever since. Some drilling was needed and I bodged together a bracket to route the chute control around the head. I store it with a full tank of Stabil'ed E-10 and i changed the oil for 1st time this spring.

 

[Eddie]

I aways taught to throttle up my lawn mower engines in a smooth way rather than Zoom Zoom.

 

[chainblu]

In the early '90s I was given a Tecumseh powered mower. It was the best mower I've ever owned. If I could buy one today, I would.

 

[Skol8480]

The mid-90's 10 hp Tecumseh I have on my snowblower is my longest running piece of OPE. A little maintenance goes a long way.

 

[AnthemBassMan]

Another Tecumseh engine fan. Except for the finicky carb that needs cleaned every so often, I’ve always preferred them over Briggs. Plus Tecumseh used an internal oil pump that helped keep them lubed better that the typical splash lube only design. They did have some not so great engines, but all manufacturers have them.

L8R,
Matt

 

[gman2304]

build a larger fire before you throw it on top.

Then pour another qt of gas on it….!

 

[wpod]

Project Farm has some really interesting You Tube videos with slow motion lawn mower carb atomization clearly shown.

All 4 stroke engines produce a strong standing wave pulse in the intake runner at certain RPM's, depending on factors like cam timing, cam overlap, intake runner length, volume and RPM. Engines that have one "carb" per cylinder are subject to some reversion (back flow) through the carb (that entrains a bit more fuel) and often produce a cloud of vapor sometimes called "stand off". You can clearly see it in the video below.

In the case of the engine in the video, they would be far better off to use a single large air filter box to contain the cloud of fuel vapor, as this controls the Air/Fuel mixture much more accurately.

Those old engines really do need the air filter assembly to be installed to contain this vapor.



But to answer your question directly, a more modern carb, if chosen correctly, will give a better result. But it will not offset the issues created by poor cam timing, poor intake valve sealing and obvious issues created by a very low compression ratio.

Tunnel Ram intakes work well because of the intake pulsing.