What's Wrong with Tecumseh Engines?

Lately, I've been reading a lot of complaints about Tecumseh engines. But lets be clear on which Tecumseh engines. I'm talking about the VH60 & the VH70 which were used to power up Deere's first true lawn tractors, the model 60 & the model 70 respectively. For the benefit of those who are not familiar with those engines, they were vertical shaft cast iron L head engines. The 60 was a six horsepower & later came the 70, which was a 7 horse. I don't know if either of these engines were in use on any other equipment besides the Deere 60 & 70 tractor. I do know however that Tecumseh also manufactured an aluminum block horizontal shaft 7 horse engine. This engine could be found in Massey Ferguson's MF7 lawn tractor from the early 1970's. It's possible that there also was a cast iron horizontal shaft as well, but I have never seen one or read anything about one ever being made.

In the late 60's & early 70's Deere could no longer ignore the pressure being brought on by other manufacturers offering a smaller, lighter & easy to care for riding lawn tractor. So in the late sixties Deere introduced the model 60 lawn tractor followed by the model 70 in the early 1970's. In 1974 the last model 70 rolled off the assembly line. The design & concept behind both the 60 & 70 was very simple & straightforward. They were designed & offered as a riding lawn tractor. A scaled down version from the model 110 which was Deere's first lawn & Garden tractor. For those of you who do not have a clear understanding of the difference between a lawn tractor & a lawn & garden tractor, watch for an article that I will be placing in the Library section on this subject. Right now I want to be brief so I can address the issue over Tecumseh engines.

Now that you have a little history as to how both of these Tecumseh engines evolved in the John Deere world, I want to get down to all things I've been reading about these vintage Tecumseh engines. First off, I'm talking about two engines that were designed & built in the 60's & 70's. The last VH70 engine to be placed into a model 70 tractor was in 1974 as far as I can set the date. I have not found any other tractor application by Deere beyond 1974, but there could be. In any case, figuring from 1974, to the current year,2009 these little one bangers have been in service for a minimum of thirty five years. And in the case of the VH60, we are talking a whopping forty years give or take a few.

Some of these engines are still running, like the VH70 I have, which has never been rebuilt & I probably will never rebuild it. And I also know of a VH60 sitting in a friends barn that still runs. Unfortunately, that is the exception rather than the rule for these engines. These engines were designed to have a service life of approximately one thousand hours, more or less within reason provided they received at least the minimal care of regular oil changes with the proper grade & quality of lubricant's, a well cleaned engine block, clean air filter & properly adjusted carburetor & electrical system.

I doubt very much that the majority of engines that went into service ever reached that one thousand hour milestone. Rather, most of them were relegated to the scrap pile because of lack of maintenance, improper adjustments & work loads that they were never designed for. Many are found with broken connecting rods, broken piston skirts, damaged or broken piston rings. In addition they are generally found with burned valves, warped cylinder heads & bent crankshafts. These are just the major items that most people complain about. I'm sure there are a few out there also that have worn bearings & journals, out of round cylinder bores & worn out thrust bearings & seals. And the list can go on from here. This is just a partial glimpse as to what many of these engines are found with.

But to hear these engines called "junk" or "Tecumseh trash" is just downright wrong. Because here we are, some forty years after they were put into service, we are still running them. And some of us are still trying to save the non running engine by rebuilding what can be rebuilt. I'm always amused by people who call these engines junk while at the same time asking where can they get a rebuild kit, or where can I get bearings & valves. I have seen these engines run for three, four and five mowing seasons without a single oil change all during that time. Yet they continue to run. I've seen these engines run at very slow speeds with a load, to the point that you would expect them to turn into a molten puddle of cast iron. And I've seen the lawn tractors that they were intended to power up, converted to other uses requiring power output well above what a lawn tractor requires. When the consumer determines that he or she knows more than the engineering staff, & starts adding on to his lawn tractor a 48 inch snow blower, or a rear mounted plow, or a cultivator & maybe a sixty inch snow blade just in case we get the ten year blizzard this season, really has no room to complain about anything that might go wrong with that engine or anything else he concocted onto the basic machine.

And most recently I saw a really nice restoration of a model 70 lawn tractor. As I approached it to get a closer look, my chin dropped to my knees. This little 70 was re worked to the owner's taste. It had over size dual mounted lug tires on the rear. Front tires doubled in size & hitched to it a home made six bottom plow. I could not believe what this tractor had been converted to. Yet they still had the original VH70 powering it. I'm something of a purest when it comes to repair & restoration. So for me to see a little 70 decked out like this was shock & aw to say the least. But I also feel that anything you own, is yours to do what you wish with it, no matter how outside the box that may be. I think that most of us that are into repair & restoration probably can't fully appreciate what gets done to these tractors. While the owner has displayed his fine mechanical ability & talent, it's just another historic tractor turned into an owner's ego pleaser. But as I said, you own it, you get to do what you like with it.

The next complaint that usually brands these engines as junk by its owner, is right after that big engine rebuild that the owner spent lots of money & time on. But here is the reality when it comes to rebuilding the VH60, the VH70 or for that matter almost, if not all of these small single cylinder engines. They just do not like to be rebuilt. Most of them want to rest in peace after having lived a tortuous life & a really difficult ending.

In conversations, I often hear the owner tell how he tore down the engine & did a complete rebuild on his own. It usually is a very macho thing to be able to proclaim that the owner alone did the entire rebuild. No need to seek out a quality small engine shop for the job according to these owners when you can make every aspect of the rebuild a do-it-yourself project. In these conversations, I will often ask a few open ended questions like "You must own a cylinder boring machine". Or "How did you re hone that cylinder bore". Or."How did you figure out how to control hone speeds, both stroke & RPM to get the proper cross hatch pattern". And I can go on and on with at least a dozen more questions like the ones above.

My questions are not with the intent to embarrass anyone or challenge their rebuild knowledge. They are only to demonstrate that for most of us, to do a complete & accurate rebuild from the raw block up, requires an assortment of dedicated machine tools as well as precision measuring devices & a lot of experience on the part of the do-it-yourself'er to have any long lasting success. This is not to say it can't be done. I'm simply pointing out the fact that many of these engines are "rebuilt" under less than minimum rebuild requirements.

The next problem that the re builder faces is parts availability. The dirty little secret is that there are hardly, if any parts still on the shelf for these two engines. You may be able to find original manufactures parts that are not over sized. That is to say they are spare parts to do a replacement with. Generally speaking, in most rebuilds you will need to move to over sized parts simply as a consequence of the rebuild. When it comes to finding over sized parts in the manufacturers inventory for these engines, it is highly unlikely they will be there. These engines are now about forty years past introduction into the market. It is unreasonable to expect any manufactured to continue to stock parts for equipment that has been obsoleted twenty five or thirty years ago.

So how are all these engines being rebuilt if the manufacturers are no longer providing the necessary parts. The overseas market of course. You will hear many D-I-Y re builders tell you about their great source for all their engine rebuilding parts. Countless numbers of on line distributors & warehouses offering "After market" complete rebuild kits. And amazingly the parts are available in whatever over sized package you need. But no one ever asks if these parts are licensed for manufacture by the original manufacturer & do they meet all the design, engineering & materials criteria set down by the manufacturer. In most ceases these parts are not licensed by the manufacturer so they are not subject to any type of approval or inspection. Most of these parts are made without any regard to quality or safety.

Parts have been found to have been cast from materials never specified by the manufacturer. They have also been found to have internal cracks & air holes & voids in the casting's. Parts that must withstand high operating temperatures, tremendous internal pressures along with all the forces pulling on these parts as they are turning well over a thousand RPM.

And finally, here comes the complaint most often heard from the rebuilder. "I did everything right, bought all new parts, and the engine just blew apart after only three hours of use". Therefore the conclusion is that this engine which stood up to some forty odd years of service & abuse before failure is nothing more than a junk pile of parts. It couldn't possibly have anything to do with the years of abuse, the wrong attitude & approach in the rebuild process or the fact that rebuild parts are just that, rebuild parts without any concern for the quality or the source.

Earlier I said that my VH70 engine is still running & it has never been rebuilt. The tractor itself has been repaired/restored, but not the engine. This machine is fully retired from any active service. It just sits with my other toys. But in the likelihood that some day the engine fails when I go to start her up for a little exercise, I will be sad about it, but it will never be classified as "junk". I will think of all the hours & service it has given. I will think about the progress made over the past forty years, and most of all, I will honor it by not attempting any type of rebuild with sub standard, inferior parts or technology not approved of by the original manufacturer. What better tribute could I possibly give this fine piece of machinery.

Also I did say that if you own it, you have an exclusive right to do as you please. So all I ask is that before you attempt any restoration upon any one of these fine engines, you consider it's overall condition & the problems you will encounter in attempting to repair or rebuild. You may come to the conclusion that it is far better to have a non running item in your collection than one that is destroyed by a failed attempt to bring it back to life. And getting back to the original complaint by many of these owners that these engines were just junk, then what is you point in trying to rebuild junk with more junk?

Have an Opinion?

If you have an opinion about the VH60 or VH70 engine or an experience you would like to share, we would like to hear about it too. Simply go to the Tractor Forum & under the General discussion forum for the Model 60 & 70 lawn tractors, place your comments there. We would love to hear from you! By: Bob Johnson