# No Spark, all new parts too



## joaklay (Nov 28, 2015)

I've got a 40+ year old Ariens Sno-throw snowblower with a 7 HP Tecumseh H70 engine and last year it had no spark. Replaced the coil, fixed and ran great. 
Pulled it out of storage this year, again no spark.
Checked kill switch (OK) but checked with it disconnected, no change.
Ohmed new coil, was OK but replaced it again anyway. Replaced points and condensor, gapped at .020", still no spark. 
Magnets on flywheel are built into piece bolted to inside of flywheel so they can't fall off.
Any other ideas?


----------



## jtclays (Sep 24, 2010)

Key to on.
Pull a plug out of any running small engine you have in the garage, plug it in the wire and try it against the block for spark. Still no spark, pull the two leads off the key switch and try again.
If you have the deadman handle on the right side, sometimes they can hang up inside the tractor assembly and the switch won't function (mouse nest, bird nest).


----------



## Jackmels (Feb 18, 2013)

31-8786 - Nova II (new improved smaller size) | Small Engine Parts | MFG Supply


----------



## Kiss4aFrog (Nov 3, 2013)

Welcome to the forum Joaklay :white^_^arial^_^0^_


----------



## skutflut (Oct 16, 2015)

joaklay said:


> I've got a 40+ year old Ariens Sno-throw snowblower with a 7 HP Tecumseh H70 engine and last year it had no spark. Replaced the coil, fixed and ran great.
> Pulled it out of storage this year, again no spark.
> Checked kill switch (OK) but checked with it disconnected, no change.
> Ohmed new coil, was OK but replaced it again anyway. Replaced points and condensor, gapped at .020", still no spark.
> ...



You didn't mention if you had tried a new plug. Did you check for spark using the spark plug grounded on the engine in a darkened area. Take a close look at points and condenser, make sure nothing is grounded in there. Also, make sure the points are actually closing when they come off the high point on the cam. There was post last week about a set of points that were misaligned and did not close properly, hence, no spark. Use your ohmmeter to verify they close, just in case.

Check both wires to kill switch / key interlock with ohmmeter. One wire from each should go to ground the other from each should NOT go to ground when the key is ON and/or the kill switch is in the run position.


----------



## nwcove (Mar 2, 2015)

clean those points, then clean them again.


----------



## micah68kj (Oct 8, 2011)

nwcove said:


> clean those points, then clean them again.


+1 on the points cleaning. *Try a different plug first* as J.Tclays and a couple others pointed out. 
:white^_^arial^_^0^_


----------



## joaklay (Nov 28, 2015)

Thanks for the replies but.....
Is a '72ish vintage, has no key and is shut off by the kill switch when throttle is closed. Not only does that test good but I've removed it's wire to the points terminal just to be sure it wasn't grounding.
The points are new and close, tested with ohm meter too.
As for trying another plug, I was using a spark tester but have now tried it by holding the coil wire just off the top of the head bolts, nothing.
Magnets work, checked with screwdriver, key is on crank.
Ohmed new coil compared to other one year coil using info found from another site, within specs.
Coil primary leads, short one grounds where condenser is bolted, other lead goes to points terminal. Ground wire is grounding, checked with ohm meter.
Very simple setup so I can't understand why I don't have spark.


----------



## bwright1818 (Dec 2, 2014)

Make sure that when you check the points, that the resistance across them when they are closed, is ZERO. (Of course, you want the coil and condenser disconnected for this test.) Even one ohm of resistance is too much. Everybody has digital meters these days, but there is nothing like an old, analog meter with a sweeping needle, for this test. You might also check the condenser as best you can. It may be new but probably came from China; so you never know. Connect an ohm meter across the condenser. The needle should rise briefly then go to infinity. Wait a minute, then, hook up again but as a low volts test. It should very briefly read something as the condenser discharges.


----------



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

+1 on jackmels and the nova II idea. Never worry about points or gap again...the conversion is very easy.


----------



## skutflut (Oct 16, 2015)

joaklay said:


> Thanks for the replies but.....
> Is a '72ish vintage, has no key and is shut off by the kill switch when throttle is closed. Not only does that test good but I've removed it's wire to the points terminal just to be sure it wasn't grounding.
> The points are new and close, tested with ohm meter too.
> As for trying another plug, I was using a spark tester but have now tried it by holding the coil wire just off the top of the head bolts, nothing.
> ...


Is the insulator insert in the side of the points housing shorting out?


----------



## micah68kj (Oct 8, 2011)

Ray 1962 10ML60 said:


> +1 on jackmels and the nova II idea. Never worry about points or gap again...the conversion is very easy.


+2 on the Nova ll. I've converted a couple machines with this inexpensive setup.


----------



## joaklay (Nov 28, 2015)

Points definitely ground off its cam, set at 0.020" by feeler gauge and that's the spec on the cover. Might try a bit less? Insulator is new, comes with points (bags say "certified Tecumseh" made in TW). Old one looks good too.
I'll check a couple things again later but as for the electronic ign. conversion, I like that idea but it says: 
"This module is not recommended for use on engines equipped with battery ignition or flywheels with multiple magnets."
My flywheel has 2 magnets so is that considered to be "multiple"?

I found a diagram showing how to install it (roughly) on Ebay. Same part's more $$ there. Installs on outside of flywheel?


----------



## joaklay (Nov 28, 2015)

Problem solved!

Upon close scrutiny, I saw that the spring type piece of metal that connects the points to the terminal was touching the points base plate thus grounding there. Bent it away with a pliers, has spark and runs perfectly once again. Don't know what was initially wrong before changing the points, etc but at least this mystery is solved.
I still like the electronic ignition conversion idea and might consider it in the future but for now, and having just bought new points, etc, might as well keep it like that for a while.
Thanks to everyone who helped out here. Great forum!


----------

