blue_collar2

The flywheel is pretty tore up...I think the bottom plate isn't aligned right. I want to take off the flywheel and balance it, but I'm not sure how to lock the shaft without doing damage. Looks like the bolt to take off the flywheel is going to take some torque to get off.

Any way to avoid flywheel damage in the future?

davewallace

My Feedback: (29)

Hi,
I found a piston stop tool which is used to arrest the piston while installing prop hubs. You can remove the plug and add some motor oil to the cylinder with the piston passed the ports. Keep the engine inverted so the oil won't go into the crankcase. This will hydaulicaly lock the pistin. Since the flywheel is in back, I think it is a left hand thread. Be gentle. One old trick is to put an old prop wood into the exhust port and put a wrench on the nut. You could drill a hole through the flywheel housing into the flywheel oppisite the magnets and tap it for a 10-24 screw. Install a screw and the flywheel will be locked. Use a gear puller to remove the flywheel. Good luck.

Dave

Website for lock tool. http://www.wholesaletrains.com/Detail.asp?ID=200303881

Volfy

My Feedback: (23)

I don't like locking the piston for unscrewing the drive shaft nut. It puts a lot of stress on the conrod and bearings. I use either a strapwrench or clamp the prop hub in a vise with "soft jaws", which could be as simple as a piece of shop towel.

Gear puller won't work on the G23/G26, unless you have one with very skinny legs. Zenoah makes a special tool for pulling the flywheel. You can make the same thing by drilling 3 holes on a thick piece of steel bar. The outer 2 match the bolt holes on the flywheel. The center one is used to push on the rear drive shaft.

You might try prying on the flywheel with a automotive door grommet removal tool, which resemble a screw driver with a angled crows foot at the end. Pry while, going around the flyhweel.

rcdude7

My Feedback: (264)

Another way to lock the crankshaft is to remove the spark plug and rotate the crank positioning the piston at the bottom of its stroke. Through the plug hole, feed enough soft cord like cotton or nylon rope into the cylinder until the crank is at the 3 or 9 o'clock position when you are torqueing on the nut to remove it. Although, if the nut is extremely tight, I would send the eng to someone with the proper tools and skill rather than risk twisting the 3 piece crank assy. and having to fix that too.

good luck

Crusty

Another way......position piston half inch or so before tdc----all ports closed----- fill through plug hole with heavy oil,replace plug, crack nut quickly, the string method is not so messy tho. I dont like those piston lock thingies, looks stessfull to piston crown
Usualy I try and find a way of locking bottom end even if it means wittling some wood to shove in the crankcase and lock the crankpin

iflyj3

My Feedback: (7)

Use an impact wrench to loosen the nut. This will not require locking the piston.

Dr1Driver

A sharp rap is what's required to break the nut loose, not a steady pull. The suggestion of in impact wrench is perfect. Be SURE of the thread direction before you start anything.

Dr.1

blue_collar2

Please excuse my ignorance...

I don't know what an impact wrench is. I have a hammer drill that I could put a socket on...is this similar?

Thanks to all for the help!

OLD_SLOW and in the WAY

take an old toothbrush and with the head removed stick it in the case to "JAM" the flywheel side of the crank lobe then loosen the flywheel nut.... doing it this way you only put pressure on one side of the crank and the chance of twisting the crank is non existantant.
then get a two bolt steering wheel puller from an auto parts store, get some long metric bolts and you are on the way to having a removed flywheel

iflyj3

My Feedback: (7)

Impact wrenches are rotary devices used by many mechanics. Most of them are air driven, however some are now electric. It is a tool that you mount a normal socket and use it to either loosen or tighten a nut/bolt.

Since it works with short high powered pulses it can loosen a nut on a fly wheel with out blocking the piston. The impulses are so quick and short that the mass of the flywheel itself keeps the shaft from rotating.

Watch the fellows at a tire change center, they use them to get your lug nuts off.

FlyingPilgrim

My Feedback: (26)

I also recommend using a pneumatic impact wrench. If you don't have one, go to a local automotive garage, buy the mechanic a cold soda, and ask him to zip the nut off for you. I've not worked on Zenoah, but spent six years repairing chainsaws, weedwhips, mowers, and tractors, that is what we always used. As far as breaking a flywheel loose after the nut is off, you can fashion a puller as mentioned above that will bolt to the flywheel and tighten the center bolt of the puller until it pops off, or if VERY careful, you can have one person hold the engine suspended by the flywheel and wrap on the end of the crank with a brass hammer. Be sure you will not bugger up the end of the crank or any threads when doing this. In fact, Briggs & Stratton and Tecumseh both had special little sleeves that fit on the end of the cranks for this purpose that protected the end of the crank from peening over (mushrooming).

GreaTOne_65

This is going to raise some eyebrows, and I'm sure some sceptizisim. If you want to save your self time and trouble, the way to remove the fly wheel nut is as posted before, an air impact wrench is quick and simple. Now for the easiest way to remove the flywheel? Turn the fly wheel to where you can strike the fly wheel on the opposite side of the magnets, don't be afraid to strike it sharply, and solidly, if it doesn't come the first time don't be afraid to keep trying. I have used this method for years, have never had it fail, or damage the engine.

Have faith, and good luck,

Dale

BobH

My Feedback: (2)

Another method similar to using a brass hammer is to use a brass drift (that's a large brass rod) unscrew the the flywheel nut to the end of the crank shaft and give it a sharp rap with the Drift. The fly wheel will pop off. You can lock the fly wheel via inserting a rod through the fins (both sides) and holding it fast. That is if the fins haven't been filed down. You can
buy piston stops at some automotive stores. This replaces the spark plug and wont damage the piston.

excaliber

Quit fooling around.
Get the piston stop, thats what all of us lawn and garden people use.
bring it up to TDC put a propane torch to the nut, heat it up use the right size socket or box wrench and it will loosen. t
then loosen the nut far enough to cover the ends of the threads and give it a couple of sharp raps with a brass hammer, quaranteed. it will pop off.

iflyj3

My Feedback: (7)

Just curious. What type of lawn and garden equipment is used in metropolis, ANTARCTICA ?

ZAGNUT

My Feedback: (1)

i'll second (or fourth??) the impact wrench method for loosening the nut. i have two makitas, one battery powered, one with cord and they both come in very handy for all kinds of jobs like this. no more messing with the blade lock on saws or figuring out how to hold a flywheel from rotating...just put the right socket on and hit the trigger.

getting the flywheel off is a problem though. the G-23 and similar engines with a shallow taper and machined (not cast) hole in the flywheel/hub can be VERY hard to get loose. whacking things with a hammer is an easy way to mess up the crank or bearings. you need the puller that Volfy mentioned above and on the real stubborn ones a few VERY LIGHT taps with a VERY HEAVY hammer will also help once you have the puller tightened up...but please hold the engine in your hand when you do this. a light hammer is useless no matter how hard you pound with it.


dave

excaliber

Iflyj3, After some many years doing that sort of stuff I retired down here to get away from all that.

Top Thumbs

I double 320 wet or dry around the flywheel grab it with a pair of waterpump pliers, and use a Box end wrench. Worked on a G62..