Ariens Techumseh breaks a connecting rod again

[HM12460]

Was looking at a new Ariens at my local Home Depot this afternoon. Can't say I was too impressed with it at all. The new MTD next to it was worse yet. The new Arien's just looked cheaply built compared to the older one's. JMO. So yeah, I get it as far as re-powering goes, if possible.

 

[dave123]

Hint if you want a decent machine you don't shop Home Depot.

 

[bubbatime]

Originally Posted By: dave123
I can't believe this many people would stick money in a 40+ year old POS.


This machine made it 30-40 YEARS. Think about that. Try to do that with a new Troy-Bilt or MTD piece of junk. Old stuff is worth maintaining and fixing. If the machine is in otherwise good condition, I would definitely re-power it with a new engine.

I have a 30 year old, 1983 Snapper 21" mower that cuts circles around most new mowers, and still works perfect. The quality is much higher than any Craftsman, Murray, Poulan, Yard Man, or low end Toro or Honda model made today.

 

[lars11]

about those rods, you didn't try and "improve" the power by overriding the regulator and pushing it above 3600-ish? A bit low on oil level combined with like over 4000 rpm may sometimes break the rods (if not replaced by heavy duty "racing" parts).
I also think it is the rpm, not the actual load on the machine, that breaks the ring at a weak spot, at least from what I read and see in those pics. They don't seem to break in a working cycle, rather by the centrifugal force.
So heavy snow and 3600 is ok but spinning loose at 4500 is not so good.
You may of course also had a bad rod, but two?

 

[threeputtpar]

I have a 5hp Tecumseh powered Estate snowblower dated 1984, and it also has the two shaft engine design. I think if you look for an Estate, Noma, Spirit, or any of the other brands made by AYP in the timeframe of 1980ish to the mid 2000s you'll find an engine that will have the two shafts. I've recently seen a couple of Estate 8hp 27" machines on my local CL that would be what you are looking for as far as engines.

 

[Cujet]

Sorry to hear about the rod issue.

I'd install a brand new rod. But, prior to installation, I'd carefully polish the rod and chamfer all sharp edges. This will reduce the stress risers and possibly reduce the chance of subsequent failure.

RPM is a factor. Keep it below 3600.

Also, I suggest 5W-40 M1, Turbo Diesel Truck, Rotella T6 or other robust full synthetic such as Amsoil small engine oil. The oil won't help a weak rod get stronger. But it will help reduce big end bearing problems, a common issue on these engines.

Also, let the engine warm up carefully.

Jacks small engines sells many replacement rods. They may be aftermarket and higher quality. Ebay too. Stens brand may also be aftermarket and better?

Good luck! Might be a cheap and easy fix!

 

[Kestas]

I did nothing to push the engine beyond its design limits. After the first conn rad failure, I repowered with a complete engine from craigslist. I have no reason to believe that engine was "improved." Nor do I have any reason to believe the previous owner knew the rod was cracked - no signs of repair. He sold it because he ruined the transmission of his snowthrower by gobbling a chunk of concrete.

I checked the oil level before using the unit, and it was only a bit below the full mark.

Thinking ahead, I plan on repairing this unit once I open the crankcase and assess the full extent of damage. I may sell it if it's that prone to conn rod failures. Though what unit would be better? I don't want anything bigger. I can barely fit this one in the garage.

 

[cronk]

I have had snow blowers with Tecumseh engines and always had great luck with them. Usually the blower is junk and the engine still runs great. It is vital on a splash lubed engine to keep the oil at the full mark. I used to check it every time before I took it out and top off as needed.
It may be hard finding replacement parts as Tecumseh went out of business. Some parts can still be had though.
If you can rebuild it, that would be my first choice, alot of older blowers used the twin shaft engine. I would run Rotella 5w40 synthetic, great small engine oil.

 

[Bror Jace]

Are these rods made from powdered metal?

 

[Kestas]

The first rod I examined looked suspiciously like die cast aluminum.

Keep in mind all Ford connecting rods are now made of powdered metal.

 

[jeepman3071]

Originally Posted By: cronk
It is vital on a splash lubed engine to keep the oil at the full mark. I used to check it every time before I took it out and top off as needed.


Another important thing is to keep the engine level as much as possible. If you spend a lot of time with the front of the blower off the ground, that means a lot of time with the oil pooling in the back of the engine, and not getting splashed around.

 

[JTK]

Yeah, the twin, counter-rotating shaft engine machines are a tough battle. There's no way to re-power with a conventional engine that I've ever seen or read about.

 

[OVERKILL]

Originally Posted By: Kestas
The first rod I examined looked suspiciously like die cast aluminum.

Keep in mind all Ford connecting rods are now made of powdered metal.


As were the rods in the International DT444

 

[Rand]

You can repower with the 100$ HF engine.

takes abit of mechanical ability.



Quote:
Engine is unbelieveably more powerful than the orginal"

 

[steve20]

in 44 years, I've only blown up one OPE engine--a 4 hp Tecumseh---in 1970---conn rod right thru the front of the block

 

[Bror Jace]

I was kind of horrified to hear that some engine manufacturers were making connecting rods out of powdered metal. I associate powedered metal with light-duty metal parts and knew some oil pump failures years ago were related to powdered metal gears.

However, doing a little sniffing around in the last week or so, I understand the process has gotten much better and is making higher-strength components ... including a lot of connecting rods. Hot rodders seem to limit them to about 400hp and 6,000rpm.

I'm assuming this Tecumseh engine was well within those limits.

 

[Kestas]

I finally opened up the crankcase to assess the damage. I'll need a new connecting rod, cam follower, and the finger that dips in to splash the oil.

How can I be sure my engine is 4HP (HS40) and not 5HP (HS50) when ordering parts, or does it not matter? The conn rod has 25-0-27 cast into the side of the beam.

 

[jeepman3071]

Originally Posted By: Kestas
I finally opened up the crankcase to assess the damage. I'll need a new connecting rod, cam follower, and the finger that dips in to splash the oil.

How can I be sure my engine is 4HP (HS40) and not 5HP (HS50) when ordering parts, or does it not matter? The conn rod has 25-0-27 cast into the side of the beam.


There should be a tag on the side of the engine stating what model it is.

 

[cronk]

There may be aluminum from the rod smeared and ground into the crank. You can use muriatic acid to dissolve it off. I usually cut a strip of rag that fits the journal, soak it in the acid and wrap it around the crank journal a couple times. Check it every 20-30 minutes and re moisten the rag. WEAR RUBBER GLOVES!
The acid will eat off all the aluminum and not harm the steel crank. Make sure when you are done you clean off all the acid and coat the crank with light oil or WD40 to protect it from rust.
Measure the crank journal to make sure it is within spec.

I believe most small engine rods are cast aluminum.

 

[[email protected]]

Originally Posted By: Kestas
I finally opened up the crankcase to assess the damage. I'll need a new connecting rod, cam follower, and the finger that dips in to splash the oil.

How can I be sure my engine is 4HP (HS40) and not 5HP (HS50) when ordering parts, or does it not matter? The conn rod has 25-0-27 cast into the side of the beam.


On both of my old Bolens snow blowers, the Tecumseh model # is stamped underneath the electric start button on top of the motor. You have to remove the 2 screws that hold the electric start plug/button, then underneath stamped in the recoil casing, is the model and serial #.

FWIW, my HS50 had aluminum melted onto the crankshaft. I took emery cloth and was successful in removing 95% of it, I think. I believe my problem was the engines governor was terribly mis-adjusted and the high speed governor RPM screw was all the way in - Im surprised it didnt throw the rod. Instead, it was probably run low on oil and with the combo of god knows how many RPMs it was running, it suffered oil starvation. Either way, it runs great now with the new parts. The bore had some scoring marks, but I couldnt feel anything with my fingernail or finger and it doesnt burn any oil. These engines can take a beating and just keep on going!