# Tech H60 no spark after reassembly



## Tommymc (Dec 13, 2014)

I just completed replacing the connecting rod in my H60 motor. It's my first time opening a motor....you might call me a youtube mechanic. As far as I can tell, everything went back together correctly. No parts left over. I lined up the timing marks, etc. In the youtube video, the guy removed the crankshaft and removed the piston from the bottom. His reasoning was to save replacing a head gasket if he went in from the top. I hammered a bit on the flywheel before coming to the conclusion that replacing a three dollar gasket was going to be a lot easier than fighting with the flywheel. 

So the motor is back on the snowblower, and I just tried to fire it up. It won't start, and the problem appears to be lack of spark. I tested this by removing the plug and holding it against the engine block while engaging the electric start. So now I'm wondering if I reassembled something incorrectly, or possibly damaged something while hammering on the flywheel. Or maybe the old plug wire didn't like being jostled around on the bench. 

I'd appreciate any advice on how to proceed/troubleshoot this....hopefully starting with the least invasive.


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## micah68kj (Oct 8, 2011)

Did you gap the points correctly? Magnets ok inside the flywheel? Do you maybe have the kill switch improperly wired? Do you have the key in the slot? Start with the simplest thing and go from there. That wojld be working backwards from what I just posted.


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## Grunt (Nov 11, 2013)

Hello and welcome to the forum Tommy. Did you by chance remove the ignition coil? If you did, did you use a business card to set the air gap between the coil and the flywheel magnets? Also make sure the throttle is in the run position and you are using a KNOWN GOOD spark plug.


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## Tommymc (Dec 13, 2014)

I did not (knowingly) remove the ignition coil or any other electrical components. The plug is a few years old, but was working last week when I threw the rod. Correct me if I'm wrong...the coil and points are behind the flywheel? I didn't remove the flywheel, but did give some good whacks with a hammer and wood block before coming to the conclusion that it's will to not move was stronger than mine to remove it. I removed the head instead. 

There is no kill switch or key. This thing is 50 yrs old......


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## Grunt (Nov 11, 2013)

Sorry Tommy, I didn't realize it had a points ignition. Your engine will have or should have an ignition cutoff on the throttle control. When you move the throttle to off, the linkage contacts a small spring that gets grounded and shuts off the spark, so make sure the throttle is set to run. Posting your engine numbers stamped into the top of the recoil shroud near the spark plug will let us know more about the engine. The numbers may be underneath the electric start push button assembly.


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## Tommymc (Dec 13, 2014)

Grunt said:


> Sorry Tommy, I didn't realize it had a points ignition.


I don't *know* whether it has points or not...I only mentioned it because micah asked about them. 

It's a Tecumseh H60-75003W motor. I'm not aware of a ignition cutoff on the throttle control. The throttle is a single cable going to the carb linkage. I've worked on the carb several times and never noticed a grounding spring. That doesn't mean it's not there...I just never noticed it. I didn't remove the carb during the dis-assembly I simply disconnected the throttle cable and the governor. I'm really hoping it's just something stupid that I missed, but I don't see any wires other than the plug wire.


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## suspicionofignorance2 (Jan 26, 2014)

There has to be ONE other wire...it's the ignition kill, and its black, and will lead up under the flywheel...You may have inadvertently snagged that wire and its caught up under the shroud, and touching the block...thus grounding out the ignition [?]..


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## jtclays (Sep 24, 2010)

Tommymc said:


> it's will to not move was stronger than mine to remove it.


That is one of the funniest things I've read in a long time
If you post up a few pics of the motor, Grunt can set you straight on those Tecumsehs. Like most have posted, there is a wire from the underside of the flywheel that goes to the bottom of the throttle mechanism. Do you have a key switch? If you track that wiring, you'll see the wire that goes up inside the shrouding to the engine.


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## motorhead64 (Dec 15, 2013)

Did you check the key on the flywheel? It could be sheared. Also, make sure the connector on the end of your plug wire is making good contact with the copper core. A good spark tool will give a better reading than holding the plug to ground. I would pan on pulling the flywheel to clean and reset the points as well. MH


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## Tommymc (Dec 13, 2014)

jtclays said:


> That is one of the funniest things I've read in a long time
> If you post up a few pics of the motor, Grunt can set you straight on those Tecumsehs. Like most have posted, there is a wire from the underside of the flywheel that goes to the bottom of the throttle mechanism. Do you have a key switch? If you track that wiring, you'll see the wire that goes up inside the shrouding to the engine.


There *is* a wire I'd overlooked running from the underside of the flywheel to the carb/linkage. I've wiggled it around, and it doesn't seem to be touching the block. No, there's no key switch. 



motorhead64 said:


> Did you check the key on the flywheel? It could be sheared. Also, make sure the connector on the end of your plug wire is making good contact with the copper core. A good spark tool will give a better reading than holding the plug to ground. I would pan on pulling the flywheel to clean and reset the points as well. MH


I didn't make note of the key. I just removed the recoil mechanism and shroud. Then backed the nut holding the flywheel out till it was flush with the wnd of the shaft. Then I placed a wood block on it (the nut) and whacked it with a hammer. When it didn't budge after a few tries, I didn't use force, I got a bigger hammer. 

It's starting to sound like the flywheel is going to have to come off...the thing I was trying to avoid. When I get the motor back on the bench, I can take some pics. Until then, any tips?


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## jtclays (Sep 24, 2010)

Make copy cat mounts for the engine, or c-clamp it to your bench. I have air tools and cheat with a blunted tip on the chisel with the nut up flush with the threads (it will walk right off). If you don't have that, you can try the pry and wiggle approach.
Donyboy has a series on the tube, look at his points tutorial also.


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## suspicionofignorance2 (Jan 26, 2014)

If you're still hoping to avoid removing the flywheel again...Then certainly check that kill wire leading from under the flywheel to throttle..."Disconnect" it...Check for spark at plug..or check it with an ohmmeter for needing to be "ungrounded"... If that checks ok, and you still have No spark at the plug...Then you need to re-remove the flywheel and see what went wrong..


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## Tommymc (Dec 13, 2014)

I have the motor back on the bench, and it looks like the flywheel key is sheared. I've attached some photos hoping somebody can confirm what I'm seeing. It looks like the flywheel may be rotated a bit over 90 degrees out of position. This would throw the timing off, right? But would that alone prevent me from seeing a spark? The photo doesn't show it well, but the kill wire seems to be clear of the block....not grounding out. 

So the sheared key would explain why the flywheel was too difficult for me to remove, right? How do I get this sucker off now? Is there some sort of wheel puller I can use, or would that damage the flywheel?


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## dbert (Aug 25, 2013)

Have you downloaded the tecumseh manual?
http://www.asos1.com/tecumseh4hp/Tecumseh.pdf
it says

_Thread the
appropriate flywheel knock-off tool part # 670103,
(7/16") or part # 670169 (1/2") on the crankshaft until
it bottoms out, then back-off one complete turn. Using
a large screwdriver, lift upward under the flywheel
and tap sharply and squarely on the knock-off tool to
break the flywheel loose. If necessary, rotate the
flywheel a half turn and repeat until it loosens (diag.
13)._

The tool mentioned is a long nut to place the hammer loads along more length of the thread. Give another go as you did before with the regular nut. Do not pry too hard, but some pressure pulling on the flywheel while you are hammering on the engine shaft to break it loose.
If it moves even a hair, it will be loose.


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## Shryp (Jan 1, 2011)

That does look like it is possibly sheared. It will mess up the timing and prevent the engine from running properly, but you should still have spark.


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## Grunt (Nov 11, 2013)

Shryp said:


> That does look like it is possibly sheared. It will mess up the timing and prevent the engine from running properly, but you should still have spark.


I agree with Shryp, the key is sheared,and although the timing is way off, you should still have spark at the plug, but far to late. That is why it is so important to torque the flywheel nut correctly when reassembling.


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## Tommymc (Dec 13, 2014)

dbert said:


> Give another go as you did before with the regular nut. Do not pry too hard, but some pressure pulling on the flywheel while you are hammering on the engine shaft to break it loose.
> If it moves even a hair, it will be loose.


Thanks for that link to the service manual. 

OKAY! I've got it off using the pry bar and hammer method (with the help of some PB Blaster.... Hopefully I can pick up a new key at a local repair shop. I'll clean and set the points. How can I troubleshoot the other components? I'm still concerned that I didn't see any spark when I turned it over.


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## scrappy (Dec 7, 2014)

A sheared key also means the magnets on the flywheel are NOT timed with the closing and opening of the points. This has nothing to do with actual ignition timing.
Replace the key it should have spark. My guess is the key sheared because the flywheel was not tightened properly.


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## Tommymc (Dec 13, 2014)

That's what I'm hoping. Everything was working fine before the connecting rod blew. My local repair shop won't be open till Monday, so I guess it's a cliffhanger till then. Fingers crossed that I get this working before we get a Nor'easter. I want to thank you all for your support.....


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## micah68kj (Oct 8, 2011)

Tommymc said:


> That's what I'm hoping. Everything was working fine before the connecting rod blew. My local repair shop won't be open till Monday, so I guess it's a cliffhanger till then. Fingers crossed that I get this working before we get a Nor'easter. I want to thank you all for your support.....


For the time being, just to test it *with the spark plug out of the engine*, you might be able to stick something in there temporarilty just to see if it will throw a spark.


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## scrappy (Dec 7, 2014)

A spark gap tester is a great test. 

http://www.snowblowerforum.com/foru...sion/32489-h60-tecumseh-runs-very-poorly.html


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## Shryp (Jan 1, 2011)

Oh yea, it is a points engine. He is probably right that the magnets and the points both have to line up. With the spark plug laying against the engine and the flywheel nut off you should be able to hold it by hand and spin it back and forth to see spark.


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## dbert (Aug 25, 2013)

Shryp said:


> Oh yea, it is a points engine. He is probably right that the magnets and the points both have to line up.


this
If it was solid state it would still spark somewhere, but this requires the one two punch in the narrow window


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## motorhead64 (Dec 15, 2013)

The key likely sheared when the connecting rod let go and the piston was free to try to "back fire." If you set the points to .020 on the highest part of the cam lobe, replace the key and torque the flywheel to specs, you should be good to go. Before putting the flywheel back on, I would continuity test the spark plug wire from the coil to the plug connector. Wiggle the connector while doing so to preclude a loose connection. Reconnect the kill wire to the throttle bracket so it can't short to ground. MH


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## Tommymc (Dec 13, 2014)

I just constructed a makeshift temporary key to hold the flywheel in place while I spun it by hand. I have spark! Things are looking up, tomorrow I'll go key shopping.


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## micah68kj (Oct 8, 2011)

For the time being, just to test it with the spark plug out of the engine, you might be able to stick something in there temporarilty just to see if it will throw a spark.
__________________
Joe

I knew the suspense was killin' ya. Happy you've'got'spark.


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## scrappy (Dec 7, 2014)

In case any one is bored enough..


"When the magnets fly past the U-shaped armature, they induce a magnetic field in the armature. This field induces some small amount of current in the primary and secondary coil. What we need, however, is extremely high voltage. Therefore, as the magnetic field in the armature reaches its maximum, a switch in the electronic control unit opens. This switch breaks the flow of current through the primary coil and causes a voltage spike (of perhaps 200 volts). The secondary coil, having 100 times more turns than the primary coil, amplifies this voltage to approximately 20,000 volts, and this voltage feeds to the spark plug."

Simply put, when the magnetic field is at full strength; the points open and cause a collapse of the field and the energy stored has to find a path to ground. With a missed timed point opening the magnetic field has come and gone and there will be no spark.

oh and pic of all this happening.

If this was electronic ignition, a sheared pin would still have spark, just not at the right time.

hope this helps to 'splain it.


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## motorhead64 (Dec 15, 2013)

Tommy,
Glad to hear you have your spark back! Make sure your new flywheel key is for your H model engine . Torque your flywheel to 40 ft. lbs. Best wishes. MH


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## Tommymc (Dec 13, 2014)

Bring on the snow! She's all assembled and started right up. Emboldened by this success, I'm going to attack the original H50 motor that I replaced a few years ago when it also threw a rod. Can't hurt to have a spare motor, right? 









Thanks for all your help!


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## CarlB (Jan 2, 2011)

glad to hear you got it going


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## micah68kj (Oct 8, 2011)

Happy for ya! I really like success stories.


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## Grunt (Nov 11, 2013)

Success is a wonderful sound, glad to hear everything is back to normal. That is a nice 1960 Chevy wagon you have.


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## Ray 1962 10ML60 (Oct 14, 2011)

Tommy, congrats! Nice machine you have there...


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## scrappy (Dec 7, 2014)

That's great. 
I'm surprised it tossed a rod and there was no damage to the block.

I'm digging the Chevy wagon. How did that ever survive all these years in Vermont?


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## Tommymc (Dec 13, 2014)

scrappy said:


> That's great.
> I'm surprised it tossed a rod and there was no damage to the block.
> 
> I'm digging the Chevy wagon. How did that ever survive all these years in Vermont?


The block has a small dimple under the electric start, but it didn't pierce. Yeah, lucky there. 

The Chevy was my grandparents. They lived in Massachusetts and didn't drive it much in the winter. It's been garaged all it's life. There's a bit of bondo and it's in real need of restoration....maybe when I retire. For now, it's enough to keep it running and registered. And of course, it gets the place of honor in the garage while my everyday car stays in the driveway.


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## scrappy (Dec 7, 2014)

Tommymc said:


> The block has a small dimple under the electric start, but it didn't pierce. Yeah, lucky there.
> 
> The Chevy was my grandparents. They lived in Massachusetts and didn't drive it much in the winter. It's been garaged all it's life. There's a bit of bondo and it's in real need of restoration....maybe when I retire. For now, it's enough to keep it running and registered. And of course, it gets the place of honor in the garage while my everyday car stays in the driveway.


Well hold on to the wagon, they are few and far between. Makes them so cool now. My parents had a 58 delray 2-door, wish they still had that.

If my dads 1967/8 10m 5 HP ever tosses a rod I would rebuild it and even have the damaged block repaired. There is some inner child within me that when that thing fires up, the whole house shakes, just brings me back to my childhood.


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## WestminsterFJR (Dec 30, 2013)

I like the measuring marks on the side of your bucket. Great idea.


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