# Ariens 72/73 910995, was running well, now seems no spark



## live4soccer7 (Sep 29, 2016)

I picked up this thing for $50 and got it running well and it just chugs through the snow like nobody's business, however the last time I ran it the blower had a hard time starting and this time I couldn't get it to start. It has fuel, oil, turns over, but won't fire. 

I pulled the plug to check if there was spark while turning it over and there was nothing at the electrode, however the wire was shocking the **** out of me so I know there is power getting to the end of the wire. Same thing if I put my finger on the end of the boot directly above the spark plug. 

I figured that maybe the inside of the boot was rusted so I took a small file and cleaned the contact point in the boot and then used some dielectric grease, still no firing.

I then pulled a plug from a working blower just to see if I could visually see spark at the end of the plug and I couldn't (I ended up using that snowblower to do the job tonight).

I tested the "test plug" and it worked on the other machine, but not the machine in question.


I'm kind of at a loss here as there is "Juice" all the way to the plug, but not passing through it. Could it be that the voltage is too low to generate spark in the plug end? This is about the only thing I can think of. 


Any input/suggestions or other trouble shooting you can think of. I've put about 5-6 hours on this thing this year and ran great until this happened 

Additional Specs I've collected: 

Ariens Snow blower 91008
24" 910995 snow thrower
Ariens IBM Number: 82014
Original Engine number: H70-130067A
Engine Number: 907300A
ShortBlock Number: 756180A
Engine Should be Governed t0 3600RPMs
Spark Plug: J8C or J17LM (J8C installed)


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## UNDERTAKER (Dec 30, 2013)

*better check the points on that 1 there.*


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## live4soccer7 (Sep 29, 2016)

Those are on the magneto behind the flywheel, correct?


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## UNDERTAKER (Dec 30, 2013)

Yep behind the flywheel.k:k:k:k:k:k:


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## live4soccer7 (Sep 29, 2016)

anything in particular I need to watch for when disassembly the flywheel. Items/markings associated with timing etc...? Thanks, the starter just seized and burned up. It's been a great day of plowing. haha.


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## UNDERTAKER (Dec 30, 2013)

live4soccer7 said:


> anything in particular I need to watch for when disassembly the flywheel. Items/markings associated with timing etc...? Thanks, the starter just seized and burned up. It's been a great day of plowing. haha.


 No timing marks. might need a puller though.


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## live4soccer7 (Sep 29, 2016)

The flywheel is on there pretty dang well. Kind of weird you have to pull 3 headbolts to remove that cover. Kind of a bad design really. It is leaking oil from the head gasket area. 

I'm thinking a few things may need taken care of it I'm taking it this far apart. Any recommendations on all parts I should get?

I need a new starter, head gasket, i've done the carb and it's good now.

I did not see any threaded points in the flywheel for a puller, unless it is a rather large puller that grabs on behind the flywheel???


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## UNDERTAKER (Dec 30, 2013)

*Yeah they have those clamp style ones that grab the edge of the wheel. *


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## UNDERTAKER (Dec 30, 2013)

might want to have a looksee at the valves and rings. check the breather out also. what do the cylinder walls look like??????????????? post some pics 4 me.


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## live4soccer7 (Sep 29, 2016)

Don't know that I have a puller that big. Might have to bust out the welder and make something.


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## UNDERTAKER (Dec 30, 2013)

live4soccer7 said:


> Don't know that I have a puller that big. Might have to bust out the welder and make something.


 You have a deadblow hammer around???????? give it a few wacks with that


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## live4soccer7 (Sep 29, 2016)

I'll give a few shots and see what I can do. What do you recommend about the oil around the head gasket. It doesn't really blow smoke, so I would think that no oil would be getting through that way.

Maybe through valve stem seals? I'm not too familiar with these engines or really any small engines for that matter. I know my way around vehicular engines well though. Unless the head bolts can somehow get oil up and through the threads from the crank, if they go entirely through. Again, I don't know these engines and am spouting possibilities.


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## UNDERTAKER (Dec 30, 2013)

Could be some through the valve guides and seals. but if is not blowing blue. then I would not lose any sleep over it.


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## live4soccer7 (Sep 29, 2016)

Thanks, it looks great when it runs (exhaust). I just dug up the info on the points in the L series manual. The whole stator almost looks new (not the coil or condensor though). Wonder if it has been replaced??? If it has then I doubt it was time properly. I'll pop the dust cover off tomorrow and take a look at the points and see where they gapped at. I've got a dial gauge, but don't think I have the little adapter on the end that would contact the piston. Any ideas for making one out of something common?

Do you know what the BTDC number is for the H70 timing? Looks easy enough to time.

If you happen to know torque specs on the crank nut that would save some looking around. I need find the torque sequence and specs for the head as well. I'll slap 'er back together and if I can get some spark going then I'm going to get some parts ordered up (HG and starter for sure).


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## Vermont007 (Mar 29, 2015)

Is there the possibility that a "Kill Switch" has been disrupted or an associated wire suddenly grounded out ?


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## cranman (Jan 23, 2016)

For pulling that wheel, take a different nut after you remove the flywheel nut, and thread it into the shaft most of the way to protect the threads. Then take a really good size hammer ( I use brass) and while putting a little pressure on the flywheel with a large screwdriver,give it a few good blows. It will shock it off the tapered shaft. The flywheel is keyed, so there can only be one way for it to go back on. Check the inside of the flywheel to make sure the magnets haven't come unglued.


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## live4soccer7 (Sep 29, 2016)

Thanks for the input everyone. 

I thoroughly checked the "Kill Wire" and it looked good. As stated in the original post, there seems to be power getting to the plug, at least intermittently, but the plug is not generating spark. I've swapped plugs and still no go. I know the plug I swapped is good as I put it back in the other snowblower and fired it right up. I'd like to replace the actual boot/connector on the plug as it is a terrible design IMO. It doesn't actually snap over the spark plug "tip", but rather just presses up against the contact point on the plug. It seems it is connected directly to the coil, so can't just replace it with a different one.



Timing is .080". Found it in the manual.
Points are .020"
Headbolts 16.5 ft-lbs (crazy, almost nothin, figured at least 30-40, but they are small).
Flywheel nut 46 ft-lbs

Hopefully that will save someone looking for the info some time in the future. I'm going to go through the timing and ignition components on this thing later today. I'll report back.


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## live4soccer7 (Sep 29, 2016)

It seems that the "Kill" wire for the engine is shorted somehow. It's not the actual wire that goes to the kill switch because I removed that from up by the carb and I still have continuity between the engine block and the terminal on the magneto housing. The points look good. I'm working on a way to turn the engine over so I can test the gap and give the points a little cleaning, but I think the root of the issue is a shorted wire. It would like be one of the black ones that go to the terminal that connects to the points. I would assume shorting it out would route the voltage through the engine block vs the spark plug wire, at the least enough to make the spark plug not work. This would make completely sense as to why it won't fire.

Let me know if my logic is off here. I'm just learning about the magnetos as I haven't worked on small engines much.


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## guilateen02 (Nov 23, 2014)

Did you make sure the wire was contacting the plug. They do sometimes get lose and sloppy amd won't contact the plug correctly. Especially with the corrosion, the walls on the connector are now thinner. I know you have it all apart now but it is worth a shot. Stick some foil in the boot and install plug for a test. If so just squeezing the boot might give you the contact you need. Also it seems lime the wire itself might be bleeding out do to you stating it shocked you pretty good. Try wrapping some ul electric tape to contain the the electricity from bleeding out. Worth a shot before tearing into good parts.


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## live4soccer7 (Sep 29, 2016)

Thanks for the input. I tried several things thinking the contact wasn't good and that definitely wasn't the case. As far as it "bleeding" out, that could definitely be happening. 

The points looks good are at .020", at least as good as I'd ever be able to get them. Tested with a feeler gauge. I don't have a way to check the timing now because I need the piece that goes on the end of the plunge style gauge. I've got a magnetic one, but need something to help it contact the piston.

I think I've found the culprit. It looks like the coil has shorted out internally. I would assume that the two black wires coming out of the coil wouldn't have continuity as one wire seems to go to the points and another wire to a ground. When you test those two wires (even when coil and wires are pulled off the magneto assembly) test for continuity. Can someone confirm this?


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## Mike C. (Jan 28, 2016)

If it was running well and then lost spark,I'd be more suspicious of the condenser than the points.If the condenser is breaking down under voltage(leaking to ground),the coil can still generate enough spark to shock you but not fire the plug.

But as others have said,I'd look very close at that plug connector.Myself,I'd cut it off and get a new screw-on one at the parts store.I hate yanking flywheels if I don't have to.


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## live4soccer7 (Sep 29, 2016)

It's all already apart and it is not the plug connector. This has been confirmed.

I think I've found the culprit. It looks like the coil has shorted out internally. I would assume that the two black wires coming out of the coil wouldn't have continuity as one wire seems to go to the points and another wire to a ground. When you test those two wires (even when coil and wires are pulled off the magneto assembly) test for continuity. Can someone confirm this?


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## Mike C. (Jan 28, 2016)

You should have a black wire that grounds to the block that is a common connection for both the primary(low voltage) and secondary(high voltage) windings of the coil.Sometimes this is actually two wires connected to one terminal.The other black wire goes to the points which completes the circuit for the primary winding.When the points close,the circuit is complete for the primary winding,the coil charges.The points open,the sparkplug fires.Forgive me if I'm explaining something you're well aware of,but many people don't understand that the plug actually fires when the points open,not when they close.

If you are using a digital multi-meter to test continuity between the black wires,you have to keep in mind that the resistance of the primary winding is rather low.A continuity buzzer will usually sound with a resistance of less than 50 ohms.Because the meter (or buzzer) is showing continuity,it doesn't mean,necessarily,that the coil is shorted.

Therefore,you would take a resistance measurement(in ohms) between the two black wires(the coil common ground and points lead) and see how that compares to the service spec.

Edit:I found a Tecumseh points ignition coil and a Briggs points coil.I tested the primary windings of both with a Fluke 179 DMM and came up with a resistance of 0.6 ohms each.The continuity buzzer rings because that tiny resistance is well under the meters threshold of 50 ohms.

Edit 2:If you have a DMM that measures capacitance,you can do a rough teston the condenser.Put one lead on the condenser wire and the other on the condenser body.It should measure between .17uf(micro -farads) and .22uf.This test will not tell you if it's breaking down under voltage,though.

If I was working on that motor,because ithe flywheel is already off,I'd put a full ignition kit in it.Points and condensers are pretty cheap.No need to worry about timing the engine,if no one moved the armature,all you have to do is set the points to .020 and timing will be fine.


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## live4soccer7 (Sep 29, 2016)

Thanks for the info. 

I tested those points and it is showing about 50-65 ohms. It jumps around quite a bit. Unfortunately, I can't measure capacitance. I do need a new DMM though as mine is quite old and is a bit finicky sometimes. I can get a ignition set for about $30, so seems like it would be worth it. 

The reason I mentioned the timing is because the actual housing that the points sits in look pretty much brand spankin new. I'll have the head off and I can just through a dial gauge up there and check it. It will be pretty easy. I'll do that prior to removing anything else or replacing points. I'm curious what it is set at.

Since I'll have the head off, should I do the valves? I mean, it is right there and surely couldn't hurt. If so, do you recommend just getting new valves or getting them ground and then "adjusting" clearance since they would sit a little lower. Let me know your thoughts or any suggestions on work to do since I have it torn down this far.


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## Mike C. (Jan 28, 2016)

I don't understand your reference to testing the points and coming up with a reading of 50-65 ohms.I thought you were interested in the resistance of the coil's primary winding,which should be less than a few ohms?

Testing resistance across points can be very misleading,especially with a DMM.If you points aren't pitted or otherwise damaged,they can be reused,but like I said,I would just replace them.

You said the blower worked just fine before it died.I find it hard to believe it suddenly went out of time and killed the spark unless the screws securing the armature came loose.Certainly nothing wrong in checking though.I took the flywheel off of my 1983 Allis last year(with points)and like yours,it looked new underneath.Everything,including the points looked nice and clean.However,the wear block on the points was worn and the gap had closed down to about .014-it ran rough.

If you're going to have the head off,you might as well clean everything including the valves and seats,especially on an engine that old,maybe even lap them.Check valve clearances after you do the cleaning.Unless you see evidence of burnt/leaking valves or large clearances,I wouldn't replace them.Grind em if they're tight.You seemed to be pretty happy with the blower's performance,if it had valve issues you would have noticed the lack of power,flame coming out of the muffler,etc.

Amazon is a great place to buy small engines parts.I've saved a ton of money trading there.I've bought original Tecumseh points/condenser kits for less than $15 shipped.I've also used Oregon and Stens kits with no issues,as well.

I should add-We concerned ourselves with the ignition coil primary,but never tested the secondary-which is far more likely to fail.A few shorted turns of wire can drop output voltage drastically.Clean the sparkplug connector and the coil common ground terminal VERY well and hook up your ohm meter.You should see roughly 2500 or so ohms.

Any voltage above about 30-40 volts can be felt,100 volts will give you a pretty good belt,but that certainly won't jump across a .030 air gap.


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## live4soccer7 (Sep 29, 2016)

Are you referring to the condensor (little silver cylinder)? I only see that and the large black coil. Thanks, I have searched around and found ebay/amazon to be the best prices. A little extra work vs going to jacks and buying all in one place, but a bit of savings on most things.


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## live4soccer7 (Sep 29, 2016)

I've got the head pulled and the valves removed. I'm going to take them in and get them machined. I'll remember to adjust the clearance. Does anyone know the specs I need to give the shop for the intake and exhaust valves?


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## live4soccer7 (Sep 29, 2016)

Found it, 45 degrees.


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## live4soccer7 (Sep 29, 2016)

Quick question. On the headbolts of the H70, the manual specifically says for there to be a washer and a belleville washer on bolts 1, 3, and 7. Do the other bolts just get washers, nothing or what? The ones I took off didn't have anything on them at all. No washers of any kind on any of the head bolts.

I think I'll get some lapping/grinding compound for the valves and clean them up and make sure they are seated nicely. My best guess is the rings are leaking a bit and that's why there's oil coming from the head gasket area. The gasket has seen much better days. 

I'm tempted to get out the grinder and do a little porting, but that's only if I get bored. I'd be curious if anyone has done any porting and noticed much of a difference or removed the "brow" between the valves that lead to/away from the cylinder. Removing any material there would mess with compression, but I'd be curious to hear what anyone as done.

I'll likely just re-seat the valves, clean it all up, and put it back together and enjoy it until it starts blowing smoke from the rings and then do a full tear down and rebuild if all parts are available to do so.

Edit: got all the parts we've been discussing ordered up. I'll get it all cleaned up this weekend.


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## live4soccer7 (Sep 29, 2016)

Got 'er all cleaned up and 99% carbon free. Should go back together this week, assuming all the parts show up. Thanks for all the help everyone!


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## UNDERTAKER (Dec 30, 2013)

*So what was the problem with it??????? I quit following this thread awhile ago.*


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## live4soccer7 (Sep 29, 2016)

It is either the coil or condensor. I've got an ignition kit and should be able to install it tonight. At the same time it is getting a new HG, lapped/seated valves, and a good timing check. I'm curious to see what the timing is at now. I'll re-check/set the timing when I install the new points too. It's sub zero here right now, so that may be the only prohibitor to doing it tonight. The stove should heat up the garage to a manageable temp though.


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## UNDERTAKER (Dec 30, 2013)

live4soccer7 said:


> It is either the coil or condensor. I've got an ignition kit and should be able to install it tonight. At the same time it is getting a new HG, lapped/seated valves, and a good timing check. I'm curious to see what the timing is at now. I'll re-check/set the timing when I install the new points too. It's sub zero here right now, so that may be the only prohibitor to doing it tonight. The stove should heat up the garage to a manageable temp though.


 The timing is lining up the 2 dots on the crank and cam that is it. they are inside the block.


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## live4soccer7 (Sep 29, 2016)

You can adjust the timing with the points/stator housing. I just checked the timing and it is way out of time. I'm surprised it ran as good as it did. Timing on it without messing with any of the timing components is .110" BTDC and it should be .080" BTDC +/- .003". This is per the manual for this specific engine. I've got the head off and a dial gauge on top of the piston and a continuity test between the stud on the points housing and the block. The very moment those points open you get a continuity "beep" on the DMM.

Once I get the timing fixed, new ignition components installed, and get the valves dialed in I think It'll run like a champ until the rings give way. Hopefully that will be at least a few years.


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## live4soccer7 (Sep 29, 2016)

Got 'er all put back together. Just waiting on the electric start to show up and I have to crimp the spark plug connector on to the end of the spark plug wire. Can't believe it didn't come crimped already. Took a little longer to reassemble, but I'm confident in the work. I'll update you guys with the results once I get those two things done and get it started. Thanks again for all the input.


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## live4soccer7 (Sep 29, 2016)

I forgot to mention. I seated/lapped the valves. What a difference that made. I ordered the permatex compound and also another compound that had a fine and course grain. The permatex didn't show up so I used the one that included course and fine. It would great. Of course, spending most of the time with the course to get it all smooth and uniform again and a finish with the fine. The mating surfaces looked brand new when finished with no visible imperfections. I didn't think it would work that well, but it sure did. Checked the valve lash spec after doing this and it was still within spec, so nothing more was needed.


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## live4soccer7 (Sep 29, 2016)

It fired up so fast I couldn't believe it. I swear it was the first compression cycle that fired it. Runs super smooth now too. I'll adjust the carb when it warms up on the next snow. Thanks for all the help guys. I hope this thread can help some other tune up their machines well.


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