I have an older Ariens snowblower with a 6hp Tecumseh engine. The motor ran fine last year, won't spark this season. The engine model # is H60-75361J, serial 2236D. I've dealt with magneto ignitions for a long time and this one has me stumped inasmuch as it ran fine all last season. I replaced the coil & condenser. (points like new, no pitting or signs of heat). New spark plug also. I even tried checking for spark in the middle of the night thinking that the spark may be just too weak to see in the daylight. Took off the kill wire from the points with no results. I've been around long enough to know that the solution is going to be something painfully obvious as these systems are just not that complicated. Would someone please point out the obvious to me?

old dave
One thing that Ariens are famous for is problems with the safety interlock device. It's tied in with the main wire coming out of the motor. The interlock is located in the transmission area. It's controlled by a lever usually located on the handle. Try and disconnect that and see if you get spark. You say you didn't replace the points....in my opinion, whenever the ignition is suspect...replace all so you can have no doubts afterwards. Also after replacing the ignition, did you retime the engine? Your timing should be set at .080 BTDC.
Let me know.

snoman

Thanks for the reply snoman. Some additional info, this is an older Ariens ST624 Model 910006 which I think dates it to around 1972. I took off the covers and cannot find any interlock wiring at all. Engine has the internal coil with the riveted stator plate. As such, would the timing have changed if the stator mounting bolts were not loosened? (I'm trying to not lose track of the fact that it ran fine when I shut it down). I cleaned the ends of the laminated plates, and the magnets in the flywheel appear strong, pulling a screwdriver from over an inch away. Not having moved the stator or points, it seems like I should get some spark, even if it wasn't coming at exactly the right moment for perfect ignition. Thoughts?

old dave
I guess we should start with some basics....have you tried another plug? Sometimes even new plugs are bad. I can't see the timing being affected if nothing was touched. I still go back to the fact, some type of safety or ignition ground wire is the culprit. Whether it is the ground wire touching the flywheel, frayed and grounding out, or possibly if you have a safety switch on the auger drive. In other words, if the auger is engaged when you try to start it, it will kill the spark.
This will be one of those process of elimation jobs.

snoman

snoman
I have been over every inch of this blower (and the parts book) and there are no electrical safety devices. This motor does not have an alternator or any other wires coming out of it. There are just 3 wires: 2 from the coil, short one to mounting bolt for condensor & the longer wire goes to the points along with the condensor wire. The kill wire from the points to the throttle linkage assembly has been removed. The wires are brand new and clearly not rubbing anywhere. Tried the spark plug in my lawn mower and it fired right up. On another angle, per your suggestion I was ordering points & a spare flywheel key from a local dealer and discovered we have a difference of opinion as to the proper flywheel key. The key on this motor is notched, with the notched end toward the motor. The man at the parts counter insists that the correct key for this model has no notch. (Tecumseh H60-75361J, Serial 2236D) That appears to leave us with one of two possibilities: 1. The parts man is misinformed or 2. My aging eyes are seeing a notch on the key when in fact the key has a piece broken off, though the notch is perfectly straight as if machined. Would you happen to know which type of key really belongs in this engine? Also, if the key is ok, could it be possible the replacement OEM coil is defective?
Thanks for your time and patience!!

oldave

make sure your coil gap is right and your compression is good. these would prevent it from firing over. but it could be the coil is defective. try a spark tester for that if you want or get the man to replace it then try the replacement.

oldave
You have definately gone over that whole machine and everything you described is correct. I would say that you should check that coil with either the place you bought it from or have it tested at a reputable shop. Sometimes coils and/or condensor can be bad from factory.
Or check to see if the points have any thing on the tips and/or are not clean. Any little bit of crud (oil film, a little piece of dirt, etc) can give you problems.
As for the key, from my very dated Tecumseh manual, the key number for your engine is #30884. It probably changes up to another number now.
Hope this helps and keep me informed.

snoman

Thanks snoman!

I was able to download & print the specific teardown manual and parts list for the Tecumseh motor. With the magneto assembly & flywheel that is on this motor, you are correct that the key part number is 30884. However, that key is not notched and the key on the motor is. So this weekend the flywheel comes back off for a much closer inspection of the key as I'm sure the notch was machined that way and not broken off. It does bother me that the "Mrs." has been quietly suggesting that I give in to the bifocals and have another look at the key...
I'll have the coil checked this week, pick up both types of keys and let you know how the weekend turned out. Thanks again for your patience and experience!

oldave

.....

i have that same motor the key is notched

Now for the rest of the story, Snoman! Finally found the time to try again with the motor. Took the new OEM coil back and had it tested, no good. Grabbed a replacement right out of the box, no good. Finally, the 3rd new OEM coil tested alright, put it in and it fired right up. Only I could get 3 defective coils in a row. (thats a quote from the Mrs...) Now for the entertaining part. I hadn't yanked the tarp off the blower in a couple of weeks, waiting on the chance to get the coil checked out. So I finally get a good coil and go out to put it in. I yank off the tarp and there is a brand new Ariens ST8526LE under it! Apparently the Mrs. thought that 1. I am too old to go back to shoveling, and/or 2. I was never going to get that H60 to fire. Yes, I am aware that neither of those responses implies a great deal of faith in my physical or mechanical skills, but it IS a new Ariens so I think it's best that I don't question the gift horse.
Thanks for your help through this process and Happy Holidays!

oldave

nice present you got. thats what i always get told. don't mess with it it works fine. but i always clean em off every year heads and all. get the same complaining. but that new ariens will give you some good operational time.

oldave
Now that's one AWESOME surprise. Your wife sounds great especially to get you the new machine. I'm envious but maybe we can talk a deal on that old Ariens you're not gonna need anymore....lol
My best to you and yours for the Holiday Season too.

snoman