OutdoorKing Repair Forum Forums Restoring, Customising and Modifying Tech Talk Removing Flywheels

All good Blumbly:) Im going out the old mans way this weekend so ill check the flywheels for you,we may get lucky. Probably grab them and stash them anyways,im sure they will come in handy one day...

There is sure to be a way of removing those flywheels with little or no risk of breaking them. Here is the way Tecumseh say you should do it for the LAV30 (apparently a later version of Blumbly's LV30):

This is EXACTLY how it should be done Grumpy ...A Little Shock Never Hurt Anyone! Erm Except Blumblys Flywheel..Bows Head*Poor Little Fella:( when im too lazy to put on my puller,I Usually try this method first,as sometimes they come up real easy

That flywheel has a very thin aluminium web, and I wouldn't use a gear puller on it myself. Honda permits it - perhaps a bit grudgingly - on at least some of its all-cast-iron flywheels, which have reasonably thick webs. This is an early GXV120 workshop manual:


However that changed subsequently. This ia a later GXV120 workshop manual:


Of course the flat plate puller in their later version is best, but for that you need either a thick cast iron web, or cast-in bosses near the center of the flywheel, and that early Lauson (LV30) flywheel doesn't have them (though from the diagram it looks as if the LAV30 flywheel does).

I think I'd prefer Tecumseh's special tool to have a controlled-depth thread in its center, made with a bottoming tap, so you could screw the tool onto the crankshaft thread until it bottomed. However bottoming taps in blind holes are not a popular manufacturing technology, so I understand why they did what they did. That special tool could be made in just about any corner garage, even without a lathe if necessary.

Agreed The Flat puller is my prefered method as the gear puller applies to much force to one area( The wrong Area)Pressure should be in tight,not around the circumference of this greater distance. Its not Contained like the tri puller and is spread out much further causing the flywheel to flex,transfering the pressure off the shaft where it needs to be, and back onto the flywheel itself dramatically increasing the risk of damage. After all gear pullers are generally for strong gears that are solid and dont have flex. Just like i wouldnt use this type of puller for a bearing,they all have their specific purposes...BUT if thats all you got well....Id at least be trying to get a 3 or 4 finger puller to distribute the pressure better. Thanks for the pics Grumpy,I often see members and have people ask me what pullers they can use,this explains nearly all of them accurately

i use a rattle hammer. its just way too easy. see this link shows how to do it.

[video][/video]

That is similar in principle to the Tecumseh method, mechanised a bit. If you hammer it very hard or for any length of time, you'll deform the end of the crankshaft so it's difficult to put the nut back on. Worse, it gives a considerable hiding to the bottom crankshaft thrust bearing, and it has the potential to bend the crankpin slightly so the two main bearings are no longer colinear. If it is a horizontal crankshaft engine with two ballraces for main bearings, you'll probably trash the one at the PTO end.

In other words, I think there is a good reason that manufacturers do not recommend this method.

i use this method all the time . it removes the flywheel so easily without almost any pressure. definately way less than hitting it with a hammer.i just recently removed a four star flywheel same as blumblys'
https://www.outdoorking-forum.com.au/forum/u...amp;Main=8137&Number=45041#Post45041
the flywheel is held down with a bolt directly threaded into centre of shaft. all i did was loosened the bolt, put my gun on top of the bolt still deep in the thread.squeezed the trigger and it was off in less than a second.
really until you try this you will never go back .bazz

bazz, in the video the guy is working on a vertical crankshaft engine, he emphasizes that he is using a very small rattle hammer, and as you said, the flywheel comes loose very quickly. If it is done exactly that way, it is probably a good method for flywheel removal - but only for vertical crankshaft engines. This is because all vertical engines AFAIK, have a plain main bearing at the PTO end. (The engines are designed that way because the bottom main bearing of a vertical crankshaft engine is exposed to major impacts when blades strike stones and pipes, as well as having to live in sludge city. I can't imagine a ball race surviving there.) If you hammer axially on the flywheel end of that type of crankshaft, the hammer blows are absorbed by the plain thrust bearing at the PTO end, and for just a few fairly light blows, a plain thrust bearing should be able to handle it. Horizontal crankshaft engines, however, frequently have ball races at both ends of the crankshaft. I have no enthusiasm at all for using either an old-fashioned hammer or a new-fangled rattle hammer, on a ball race, including the one at the PTO end of a crankshaft.

Hence in my opinion the use of a small rattle hammer very briefly on a vertical crankshaft engine to remove the flywheel makes sense. Using a bigger rattle hammer, or a multi-second burst of hammering, is a different situation however.

Years ago I used to complain about people assembling engines with rattle guns, because they rarely reduced the torque to a safe level for the parts concerned, and even used 12 point sockets instead of 6 point, so they ruined the hexagons on the nuts as well as often stripping the threads. Realistically however, that is blaming the tool itself for the fact that it is being used by an idiot. I took that negative attitude because nearly everyone I saw doing it that way was indeed an idiot. However it is bad science to extrapolate, and bad logic to blame the tool for having an incompetent operator. By now there may well be people in the trade who are competent to adjust the torque to suit the bolt they are doing up. (I'm not too sure that any of those new improved people work in tyre shops though - I still seem to see most of those guys ruining every wheel they attach to a car.)

yeh grumpy. i see your point. a lot of home diy ers should be kept away from small engines. the stuff thats been done to some ive bought would make you cringe.

Good rule of thumb, strip it fast and build it slow. And in reference to the tyre shops - I work at a garage up the road from a small Beaurepaires store (now closed). used to do some mechanical work for them, (replacing wheel studs on front wheel drives mostly), Always wondered how they f**** so many wheel studs. Was picking up some tyres one day and talking to the manager who was refitting some wheels- he placed the wheel nut in the socket on the impact gun, placed against stud, hit go button. No wonder 1 in 4 stripped the treads. Idiot.