Tecumseh 5.5hp Runs Strong, Dies Intermittently

[chesbaycruiser 83]

So the back story is that I brought home some lawn equipment from my parents house to clean up and sell for them on CL, as they are preparing to move into a retirement community and don't need the stuff. It's all in good shape and for the most part has been dealer serviced. This particular mower is a commercial grade Ariens 911, 5.5 HP Self-propelled. My parents purchased this new in 1990 for $500, and a comparable new unit sells for upwards of $800. Of all the stuff I brought home, I saw this as probably the most lucrative for them, but there is a problem that I have since learned has existed since they stopped using it and bought a different mower years ago. That it, it would just "die" for no apparent reason.

Since it had been sitting for years and wouldn't start at all, I cleaned it up, drained the fluids, cleaned the gas tank, rebuilt the carb and replaced all the filters, plug, primer/fuel line. The unit will now start and run well, but still has the old problem of just cutting out. I thought it might be a venting issue, but a new gas cap has not solved the problem. There doesn't seem to be much rhyme or reason to it; sometimes it runs fine for quite some time, sometimes it will shut down after only a few minutes. The last receipt I found for service (1997) states "Customer comments: cuts off when gets hot. Tech: Ran for 2 1/2 hours, ran OK". It usually starts right back up if I pull the cord.

At this point I'm torn between pursuing the problem further to fix it, and just selling it "as is" at a cut-rate price to get my money for parts back out of it and getting it out of my garage.

I'm thinking if I proceed, the Ignition Module is probably my next theory, but I would appreciate any other thoughts or suggestions.

In the spirit of full disclosure, (although I have no reason to believe it is related to the aforementioned issue), there is also an oil leak. I have not investigated that very far yet beyond checking the drain plug which is in tight. I guessing a seal or gasket, but that's a bridge I'll cross once I make the call on the other issue.

FYI...the engine is a 5.5 HP Tecumseh TVS120-63111F, S/N 9307N.

Thanks in advance for your input....

CB

[MarkPalmer 81]

Those Tecumseh "Vector" series engines are known to be troublesome, and ignition coils comprised a lot of the trouble so I'm guessing thet's where the cut-off problem will be. Parts for them are getting a bit tough to come by as they weren't on the market for a long time.

-Mark-

[chesbaycruiser 83]

Thanks for the input Mark.

For the record, the Tecumseh parts diagram/list for this motor is pretty much useless. Different parts with the same part number, parts on the diagram with no corresponding part number, exploded view scanned so terribly that many of the numbers are illegible. Grrrrrrr...

[MarkPalmer 81]

The Vectors also have a lot of real chintz plastic parts that tend to warp like housings, intake manifolds, even much of the carburetor is plastic. I like the old Tecumseh engines like the cast iron HH's but when their answer to reducing costs in thier later years was to make complete garbage its no surprise they met their demise.

-Mark-

[AmalgamousProxy 2]

It could be a faulty safety switch or kill switch. Locate and unplug the small wire going to the ignition coil and try it. If it does not stall out, you likely have a bad switch or the wire rubbed through some where along it's path. If it still acts up with that wire off then it is probably a carburetor problem. I know those engines can suffer from vapor lock, once it dies quickly unscrew the cap and listen for a sucking sound if you hear that it could be a bad vent valve. I know you said the cap is new but as an adage I use goes: Just because a part is new it does not necessarily mean it's good...

P.S. Don't unplug the kill wire and start it unless you have someone there with a wooden stick to pop off the plug wire for you. Otherwise you could burn up your engine brake when you let go of it (if equipped). Don't use anything metal or you could taze yourself. I prefer to loosen up the wire before hand so I know it won't take much effort to get off just in case. If you have a large yard, just mow till it runs out, the ultimate test. :twocents-twocents:

[chesbaycruiser 83]

Update.

After pulling the sheet metal off to get to the ignition module, it became evident that the oil leak I assumed was at the bottom of the engine was actually up top. Since I had already bought a new gasket set anyway, I went ahead and tore the whole thing down. Had the machine shop check it out and the engine was good inside, so just going to add new rings, try out my new Flex-hone, lap the valves, and install all new gaskets and seals. (And of course the new ignition!)

Getting ready to leave town tomorrow morning, so won't be able to get back on this until next week.

Will try to post some photos and let you know how it turns out when I get back...

CB