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firestix_gw

removing the big ole nut on top of the fly wheel

firestix
12 years ago

I hate to ask this as it looks like the answer should be self evident and/or a no brainer from all the other flywheel removal posts.

How does one get that big nut off the top of the engine. I'm recalling something that looked like a strap wrench and a normal wrench. I tried using a normal belt but I cant get a good hand on it to torque that bolt off. Is there a trick here beyond dousing with PB blaster? Or should I just go ahead and get the right tool for the job?

That being said Ill probably get the flywheel puller while I'm at the shop.

Comments (17)

  • Greg Goyeneche
    12 years ago

    I think you answered your own question, "Get the right tool for the job."

    First you need to hold the flywheel. Best tool is a flywheel wrench like Briggs makes. Expensive at $35 and they make three or more sizes. Distributes pressure to several fan blades, so you don't break them. Next choice would be a strap wrench. I have an older Snap-On I picked up for a couple of dollars. Costs about $40 new, but can handle most flywheel diameters. Less high tech is to stuff some rope down sparkplug hole so that piston interferes and you can wind off the nut. Works, but not as elegant.

    As for the nut, correct socket with a flex handle or tee handle is best. You can also use an impact wrench to remove, but I'm a little leary of using an impact to re-tighten. Too much torque and you can split the flywheel like a melon (right thru the keyway) or strip or pull the threads off the crankshaft stub. Either way, job has quickly become more expensive.

  • mownie
    12 years ago

    And when you get to putting the flywheel on the crank later, follow this advice to the smallest detail.
    Tapers of the crankshaft and flywheel must be completely dry and free of any traces of PB or oil. Solvent wipe with carb cleaner, lacquer thinner, or even just a bit of gasoline on a towel. Use caution, they're all very flammable
    Carefully set the flywheel onto the crank, aligning the keyways.
    Insert the key into the keyways (you can "jiggle" the flywheel slightly if needed but don't lift it).
    When the key is started, gently tap it down til it is nearly flush with flywheel surface (but not below the surface)
    Install the retention nut and torque to 145 foot pounds.
    Deviate in any step and you might have problems later.

  • firestix
    Original Author
    12 years ago

    Looks like I may be going the rope route... The "proper" tool was $70 and I couldn't find a strapwrench any longer than the one I have at any of the local stores. But before I get un-elegant ill see if I cant come up with some combination of a my belt and my strapwrench.

    Thnaks so much for your help.
    -Kirk

  • mownie
    12 years ago

    The rope trick will probably be the best for your situation.
    You don't need to worry about hurting the Vanguard..........from your initial description of its failure, I think it's beyond hope anyhow. Possibly broke a connecting rod when it failed. That might mean you will have to swap the rope over to the other cylinder (Vanguard engine) if your first choice of cylinders turns out to have "no resistance".
    The Twin 2 (being a flat head engine) does not have the concerns about bending a valve against the rope like the Overhead Valve Vanguard engine. Good luck

  • firestix
    Original Author
    12 years ago

    Or not. The vanguard shaft is no longer connected to the pistons. I thought I had it with my belt and the too short strapwrench but it seems i broke my belt. Now i need a new one just to hold my pants up :) I'm not sure what $35 tool your talking about but the B&S strap wrench AKA Flywheel wrench came up as $77 Tried Lowe's, Home Depot and Sears only to find the largest strap wrench to be about 12". tomorrow I guess I will try bolting the belt (broke at the buckle) to the strap wrench. To help anyone with the same problem stumbling upon this thread I ordered an OTC strap wrench $30-50 depending where you look as opposed to the $65-80 for the official B&S. Now i wait on shipping cause I'm cheap or I actually get it off with my now broken belt the too short strap wrench and a few bolts.

  • krnuttle
    12 years ago

    If you have a rubber bungee cord it will give you a better grip on the flywheel.

  • firestix
    Original Author
    12 years ago

    Got the Vanguard off. A piece of angle iron and a bolt on the intake and the bolt that would hold down the cooling fins. It bent the angle iron a bit to get around the nut and the raised part around it but held strong whilst I cranked on the wrench and POP!

    So if you stumbled across this thread and looking for an even cheaper tool... if you can find a place about level with the flywheel with a bolt consider using angle iron betwixt them. Still working on the twin II; It has no convenient bolting location and that nut is all rusty so I may have to douse it a few more times with PB. Even if you don't have a convenient bolt hole you can bolt some angle iron in the fan blade hole and try with a crowbar between it and your wrench. However for me I just bent the everlovin' snot out of the angle iron. Which makes me wonder how the strap wrench on the plastic blades is going to do so much better. I really don't want to have to go purchase a torch to fire it up! Then again maybe I should get myself a torch. I seem to keep running into bolt and nut problems.

  • User
    12 years ago

    " I really don't want to have to go purchase a torch to fire it up".

    Cheap propane torch at the box store... heat till spit sizzles then spray PB Blaster. The heat will wick the chemical into the threads. Let it cool a bit then repeat as necessary.

    DON'T overheat!

  • mownie
    12 years ago

    As has been said already, you will not hurt anything on the Twin II by feeding a foot or so of 3/8" rope into the cylinders through the spark plug hole.......L-head engine......valves ARE NOT situated above the piston.
    And because the pistons are in lock-step movement in the Twin II, both pistons rise, and fall.....simultaneously, so you can feed some rope into both cylinders to get the maximum benefit.
    Works the same when you go to torque the nut later.
    Now, OHV engines require much more care with the old rope trick, but L-heads don't care at all.

  • firestix
    Original Author
    12 years ago

    Thanks guys I have successfully swapped the stator. Getting the nuts off was an adventure and now I have a giant unused strap wrench. I guess its there for next time when I can have the elegance factor.

    So for anyone stumbling on this thread... What eventually worked sans a giant strap wrench?

    The Twin II: The rope trick! I would suggest this to anyone over the strap wrench. With the torque I had to put on that thing to get it loose I seriously doubt the cooling fins would have come away unscathed. On top of that it leaves both hands free to apply torque, heat and PB to the nut. Yes I ended up firing it up with a torch and blasting it with the PB several times. One thing to note when buying rope, don't confuse 3/4 with 3/8 or you'll be buying two chunks of rope over two trips. ;) On a similar thought if you got the 3/4 and tried to use the inner bit to do the trick and the engine turns over with the rope in there; you didn't shear the rope core in the engine. You just mushed it flat. Now you wont have to take of the cylinder head and go looking for proper torque speck to put it back on. Just start with 3/8 rope.

    The vanguard that had no connection to the pistons: Like I described above a piece of angle iron bolted to the flywheel and another sturdy part of the engine worked the charm.

    As for re-installation I followed Mownie's advice. Thanks for that. The last thing I want is more problems down the road.

  • mownie
    12 years ago

    OK, good so far. Now, please let us know how the battery and electric PTO perform after you have used it a bit.
    I believe you will be fine.

  • arceeguy
    12 years ago

    Getting the flywheel nut off is a breeze. Use a small impact wrench. I use an inexpensive Harbor Freight model for small engine work. I don't even drag out a large compressor, a small one (like for air nailers) will do just fine as you only usually need a few second burst to knock them free.

    The tough part is getting the flywheel off. This is where having the proper tool is important. Never hammer the edge of a flywheel or pry a flywheel with a screwdriver. Use the puller that the manufacturer recommends. I've seen what can happen if a flywheel lets loose because it was damaged from hammering/prying. (it really makes a mess of the housing!)

  • firestix
    Original Author
    12 years ago

    Ok so those of you following this for the electrical repower go over to my other thread ... linked below. updates will show there, as the updates will now concern the electrics and not the big ole nut:)

    Here is a link that might be useful: the electrical thread is here.

  • Marshal Kilburn
    3 years ago

    Just looking for a little advice, i have a briggs 18hp intek twin cylinder, trying to remove the flywheel. I'm using a flywheel puller. I removed the lock down nut. I've put blaster on it several times. It will not come loss. I've applied heat twice, still will not come loss. Any one have a solution?

  • Marshal Kilburn
    3 years ago

    Skip that once it cool down it popped

  • wprice23
    3 years ago

    The approx. $40 HF electric impact has removed every nut I have ever tried.

  • HU-989590164
    2 years ago

    I have a 2003 Briggs 24hp twin cylinder Intek and I purchased it used and missing the flywheel fan and but to mount the flywheel! Thinking no sweat, I should find that part easily! Boy was I ever wrong! First attempt the nut seemed too small and second attempt seemed the same but I noticed that it was the thread pattern that was off! The crank has finer threads than both the the nuts I purchased! So what do I do now? All I keep seeing is the same nut online with no mention of thread differences and both claimed to be off of the same type engine! I'm stuck with little ideas on how to get the right flywheel but for my engine! Please help if you can!

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