Outdoor Power Equipment (Lawn Mowers, Snow Blowers, Chain Saws and more) Discussions

Guys,

I have 2 Tecumseh Snow King 8hp engines.

One is a "HMSK80 155444S (D) 3348D", in my old MTD and has an alternator (but no light). The flywheel is 611093. It obviously has magnets in it (I have measured voltage from the alternator while running).

The other is a "HMSK80 155316S (D) 3159D", in my "new" Ariens ST824, and does not have an alternator. The flywheel is 611091. I saw something saying that 611091 does not have magnets.

I'd like to move the alternator to the engine that doesn't have it, so I can add a light to the new machine. I took some shrouds off the alternator engine tonight, hoping that I could simply unbolt the alternator. Naturally, it can't be that easy. The flywheel would have to come off of each machine, to swap everything around. It sounds like the flywheels would also have to swap. I've never removed a flywheel. For that matter, I've never had a headlight on a snowblower. I like the idea of a light, but I'm now wondering if it's worth the trouble, and the risk of breaking something in the process :) I have 2 working engines currently. I don't want to end up with 0 that work.

Can anyone give me a sense of how difficult & risky it is to remove a flywheel? For what it's worth, the Ariens appears to have been stored outside at some point, and is quite rusty. So that could perhaps be a factor in trying to remove its flywheel. Any feedback would be appreciated. I've gotten by this long without a light, maybe the smart thing is to leave everything alone, and sell the MTD the way it is. Thanks.

Well removing a flywheel with an engine bolted down can be a problem.  The way I always remove them even if it means taking the engine off.  Is to removed the shroud then the starter cup.
Screw the nut back on the shaft almost all the way.  But leaving a few threads not on the shaft.   Turn the engine on it's side so it's resting on the output shaft.  Then pick up the entire engine.
by lifting it up by the flywheel with one hand.  Put your fingers underneath the flywheel in one place and pick up the engine about two inches of the floor.  It's best to do this on a rug or with
a thick towel underneath.  Hold up the engine and hit the nut with a hammer.  Hit it hard (like your trying to drive a 16cc nail into a 2x4) and the flywheel should pop off the shaft (actually the engine drops off the flywheel).  Gravity does the work.  A heavy brass hammer is best to use.  Hit the nut squarely.  If you haven't done this before it might not be a bad idea for you to tape a thick washer on top of the nut before you hit it.  Be aware that the engine is going to come loose from the flywheel and want to fall over.  Probably on your foot.  I've never had a flywheel that wouldn't come off using this technique.  One to three blows is usually all it takes.

They used to have puller bolt holes in some flywheels.  But not all brands of engines have or had them. 

You can also try just using large pry bars, screwdrivers or crow bars to wrench the flywheel loose.  By prying on the flywheel from behind.  But you have to be very, very, very careful what
your prying against.  You could pop a hole in the block, or crack off a cooling fin.  And the flywheel would still be on the shaft.

If you have some suitably sized hardwood wedges, you can try tapping the wedge under the flywheel to exert a bit of upward pressure.  With the crankshaft nut loosened and backed off the flywheel but still on, give the nut/crankshaft a good whack with a hammer.   Tap the wedges in a bit more and tap the nut/end of crankshaft again.   If you can't get wooden wedges in, try using a big screw driver to lever the flywheel upward while tapping.  Some come off real easy.  Others real hard.  If that don't work, you might have to either make yourself a device to pull it or get a puller. 

Look to see if there are a couple or more threaded holes in the flywheel.  If so, they're used to pull the flywheel.   The way I do it using the threaded holes is to get a piece of 3/8" steel plate and drill suitably sized holes in it to match the holes on the flywheel.  Find bolts that fit the holes in the flywheel approx. 2" long.  Make the holes in the plate just big enough to drop the bolts through.  Back off the nut that holds the flywheel on until it's a couple threads above the crankshaft.  Put a spacer between the plate and nut that will not interfere with the bolts.  This will give you the vertical distance you need to pull the flywheel upward.  Start tightening the bolts evenly so that they all are pulling upward with equal force.  Continue until the flywheel releases.  If the bolts are too long, get shorter ones.

Lots of good info, thanks guys. I don't plan on removing the engines (that's well beyond the scope of this little plan). I just checked the de-shrouded engine, its flywheel does not have tapped holes for a puller. I *might* try your trick, borat, of loosening the nut, trying to find a wedge or two, and giving it a few whacks to see what happens. Or, frankly, I may just give this up as a bad & risky idea, and skip the whole light concept. I haven't had one until now anyhow, and I just can use a headlamp (miner's light) if I need to see a bit better. If this just involved taking off the covers, removing two bolts, and moving the alternator to the other engine, I was up for it. But pulling 2 flywheels, swapping them, etc, seems like it this may have the makings of a bad idea.

Interestingly, the Ariens parts manual does show an optional alternator, 02455800, which looks like maybe it goes in the recoil starter housing, or replaces it? But it's $70 for just the alternator, and I'm not that desperate for a light :)

If you do follow thru on this, you'll want to determine which alternator you have.  You'll probably find the MTD has an 18 watt light alternator (a single lead coming out from under the flywheel).  This alternator produces minimum 10 VAC @ 3600 RPM.

If you do get the flywheel off each engine and swap the alternator and flywheels, you might consider this for the lighting.  A tractor light with a PAR36 18 watt sealed beam, either halogen or conventional incandescent.  Amber color would be nice too.  Supposedly, it is better if it is actually snowing.

http://www.homedepot.com/h_d1/N-5yc1v/R-202498035/h_d2/ProductDisplay?langId=-1&storeId=10051&catalogId=10053

You just need to confirm that the bulb is 18 watt or replace the one that comes with it.

Guys, thank you for your suggestions. I decided to give this a try. I started with the "donor" engine, that had the alternator. Removed the flywheel nut (thank you again, Harbor Freight impact wrench), and took off the "cup" that the pull starter engages with. Put the nut back on, and screwed it on until it was sticking just above the crankshaft. Gave the nut a whack or two just to see if the flywheel would simply fall off, it didn't. Tried a long flat screwdriver, between the engine and the flywheel, to pry it while hitting the nut with the 2-3 lb mallet, that didn't work. So I grabbed a crowbar, put it up against a solid part of the engine (above the flywheel, towards the spark plug), pried gently against the flywheel (I wasn't pushing hard), and grabbed the mallet again. In 2-3 whacks, the flywheel popped right off. Success!

So today I tried the other (rustier) engine. Did the same thing, crowbar against the engine, flywheel nut sticking up a little bit from the crankshaft. Needed about 7-8 whacks this time, then this flywheel popped off as well. Swapped the alternator and flywheel-with-magnets to the target engine, set the ignition coil gap back to about 0.012", and reassembled the rest of what I'd taken off. Also replaced the fuel line and added a fuel filter while I was in there, and put on a new spark plug. Just tried it, it seems to run fine. Took several pulls before I got a pop, but I'd also drained the carb bowl, etc, so maybe it was still just getting some fuel back through the system.

The biggest snag with this method was that I didn't hit the flywheel nuts squarely, so I dented the tops of the nuts a bit, and kind of distorted the top thread on one of them. So now I have a flywheel "locknut" which won't simply vibrate loose :) If I had more hands, I would have held a piece of aluminum/brass between the mallet and the nut. Or I could have used my plastic-faced deadblow hammer.

I torqued the flywheel nut to 40 lb-ft, because I think that's the proper torque for an iron flywheel, from looking at the Tecumseh technician's manual. The engines have solid state ignition, I don't think that's the "external ignition" that the manual says needs 58 ft-lb. If I need to torque it to the higher value, because I misunderstood the manual, please let me know so I can redo it.

   I"ve always understood "external" as not under the flywheel.

RedOctobyr, you are the flywheel-removing king!

trouts2, thanks. I was afraid of that, though it kind of makes sense. If the coil is at the outer edge of the flywheel (regardless of the style), it's at a larger radius, and will exert a greater torque against the flywheel when the magnets go past the coil. That, presumably, contributes to why you need a greater torque on the flywheel nut to hold the flywheel in place relative to the crankshaft, and keep it from spinning and shearing off the key. I took the pull starter shroud back off and tightened it to 58 ft-lbs.

I picked up an Optronics TL-10CSW round utility tractor light today at Walmart for $12, along with a switch and some wire. Unfortunately, the included bulb is 36W, it's a PAR36 4411 bulb. My alternator can only put out 18W. I'm afraid I would damage the alternator by trying to draw more than its rating. I apparently need to get a PAR36 4414 bulb, which is 18W. Looking around online, the best price I can find online for the bulb is $15+ after shipping. Given that I paid less for that for the whole light, I am hoping I can find the bulb cheaper locally :) If anyone knows a cheaper source, I'd welcome any info.

A tip- if you have a light like that, and you need to remove the bulb, here's one way to do it. The housing is a stiff rubber, you need to stretch the housing out to a larger diameter so you can push on the back of the light, and pop the bulb out the front of the housing. I tried to do that a winter room temperature, and could not. So I set the oven to Warm, and put the light in the oven for 10 minutes. Took it out, the rubber was soft and flexy, I stretched the front of the housing and pushed on the back of it, and the bulb popped right out. I hadn't found any useful info on how to remove the bulb, so wanted to share what I tried, in case it helps anyone.

Light:
http://www.walmart.com/ip/Utility-Flood-Light/16680060

manjestic, I know a lot of the light info is a rehash of what you mentioned above. And the light I bought is very similar to the one you linked to, but I was able to find this one locally, whereas Home Depot only sells that one online. But the bulb numbers were confusing me for a while, so I wanted to mention that 4411 bulbs appear to be 36W, and the 4414 bulbs are 18W. I was searching for a 4411 18W bulb, for instance, because I hadn't yet figured out that the 4xxx numbers apparently correspond to wattage. The PAR36 is the bulb size, and remains the same. There are also trapezoidal-beam, spot, and flood bulbs. My light came with a trapezoidal pattern bulb. The trapezoidal or flood seem to be the style you want for this purpose.