OutdoorKing Repair Forum Forums Repairs and Maintenance Questions on Engines Questions On Victa Two Stroke Engines Victa 160cc Engine Flywheel Removal

Ive started to disassemble my engine using the manual in the lawnmower manuals section. I was looking through what i had and i realised the pages are out of order and appears as though a page is missing. I couldnt find any information on the removal of the flywheel.

How do i remove the fly wheel? Its a 1974 series 70 MKIII 160cc engine.

Thanks in advance

Some people have luck getting them off by undoing the nut and applying gentle pressure with a bit of patience. I am rarely gentle and rarely have a lot of patience so I use a puller like this:





My puller is home made but works very well, it threads into the 3 holes around the main nut and with the center nut removed, the big bolt on this puller pushes o the crankshaft and heaves it off. You do need to be careful as I have managed to buckle one crank before form the flywheel being so tight, sometimes leaving the center nut on but loose to get it started is a good idea.

The Briggs puller only has 2 screws instead of 3. More importantly, it leaves out the center bolt, like this:




The second pic is from the B&S overhaul manual, and it shows how you use it. Note in the pic my puller has the nuts on the opposite side of the plate from the bolt heads, for storage. When you use it you have the nuts on the same side as the bolt head, as shown in the diagram.

You can use this same type of puller on your Victa, but make a larger flat plate with three screw holes instead of two. Loosen the flywheel retaining nut until its top surface gets to the end of the thread, so it can help support the force applied by the flat plate to the crankshaft. This type of puller has no tendency to slip sideways. The screws pull the flywheel while the center of the plate holds the crankshaft still. As long as you tighten the two nuts evenly, so both bolts apply the same force, the only thing that can go wrong is if you tighten the nuts too hard, you will strip the threads where the screws go into the flywheel itself. To keep this from happening, apply a moderate amount of force to the screws (by tightening the nuts) then tap the exact center of the flat plate, directly above the end of the crankshaft, with a hammer. Tap, don't belt, just once, then see if you can safely tighten the nuts slightly more, tap again, and so forth until the flywheel moves. (With the Briggs it all happens with a loud bang when the flywheel comes off the taper, but it should be a lot more gradual with a Victa).

i must have missed something totally, i thought that once the nut in the centre came off (which is where im stuck) the fly wheel would come off. Is there some proceedure to remove the centre nut? I thought there may have been some kind of tool to stop the fly wheel from moving which would allow you to remove the nut. The condition of the nut on my flywheel would indicate that someone has tried to remove it and failed or has been serverly overtightened as the nut is partially rounded on the points. are the 3 raised areas on the centre of the flywheel for the 3 bolts of the extractor? Im pretty sure there are no holes around the centre.

Sorry for sounding clueless, and excuse me as im still new to victa engines

Removing the flywheel nut requires restraining the crankshaft from rotating, or using a rattle gun. If the thread on the crankshaft is rusty, you need to wet it with Penetrene for a couple of hours first. Also, if there is rust, you need to get the Penetrene to soak in between the crankshaft and the center of the flywheel before you pull the flywheel off.

If there have been previous failed attempts to remove the flywheel nut, you may have a difficult process ahead of you. My method, for what it is worth, is to file the damaged nut so that a socket will fit on it tightly, bearing on all surfaces, then use a rattle gun. The advantage is that it gets the job done in a couple of seconds with no damage. Of course you then need a new flywheel nut when you reassemble the engine.

The flywheel can't be removed until the nut is removed.

Okay, thanks for clearing that up for me. So im guessing once the nut comes off, the starter cup/cone comes off, are the 3 holes mentioned under this cup/cone? Also is there any specific way to hold the flywheel? The flywheel is missing a few fins and i can see obvious damange where someone has previously used a screw driver against the crankcase to try to immobilise it; with no success judging from what i can tell.

Hi Sanchezz, as far as I know, the nut is integral with the starter cup....it is part of it, at least is was on my early Victa.
Once the cup is off...you apply Penetrene liberally around the crankshaft and key-way for a couple of days to let it seep in which will make it release easily from the tapered shaft, one the puller is applied.

Here is a pic of the genuine Victa Service Tool for removing the flywheel....
Hoping this helps.

If you are missing some fins, you should replace the flywheel anyway.

The fins are only a good enough way to restrain the flywheel if your anti-rotation tool grips at least six of them evenly. Briggs made a special tool for doing that with their engines. Realistically, that isn't something the average home repairer can make. Remember, the nut isn't all that hard to remove unless it is rusted on. If it is rusted on, that problem can be eliminated by Penetrene. (WD40 is a poor substitute.) If you can make a very rigid socket spanner adapter and smack the end of it circumferentially with a heavy hammer, you may get lucky. Really, though, the answer is a rattle gun if it is a difficult one. You also need a six-point impact socket, don't waste your time with a 12 point socket, and the socket has to fit the nut tightly.

Grumpy, the nut is situated down the bottom of the cup, there is no room to tap anything. You need a socket with an extension and a rattle gun or ratchet handle to get it off.

The nut is seperate from the cup, but buried right in the bottom, if you dont have a rattle gun I generally stuff about a meter of 8mm rope fown the spark plug hole and use that as a crankshaft lock. The conrod is very strong on these, I am yet to break one.

I hate the rope solution Joe, but I know you have a lot of experience with it, and it works for you. Because the con rod is in compression, I think it is less likely to break than the piston crown.

Another ugly solution that is likely to work, is clamping the blade plate to the mower base, then using a socket on the flywheel nut. The reason it is ugly, is the crankshaft is taking a lot more torque than it should have to. I think it would be stronger than the piston and rod, at least.

Thanks for clearing that up Joe, I thought the nut was integral...at least it was on the 'coffee table'.

thanks so much guys, a wealth of knowledge! ive had a good look at the engine again since ive been home from work (i was at work when i posted previously) and can see the 3 holes under the cup. I wont be able to do the rope trick as the top end of the engine is in pieces. Ive got an electric 12V rattle gun which i dont know how to describe the process, but it builds up speed and once it gets to a point the socket starts to spin, kind of like an impact driver. I'll rework the nut and try my luck. Whats Penetrene and where can i get it? ive never heard of it before.

Penetrene is a penetrant fluid, oil based. It works better than any other I know. You can get it at Repco, and probably many other places.

Try to attach as much inertia as possible to the crankshaft when you use the impact wrench. The blade plate, for example.

Hi again Sanchezz, would it be possible to post some pics before you start and as you go along...it would be really great for our archives...for future members with the same probs....Thanks mate.

sweet! i'll drop by repco tomorrow on my way home from work. Havent touched the engine yet, been busy, but yeah not a problem, i'll take some photos along the way

Ok, so ive got the flywheel off and the engine is all in pieces now. I took a bit of a different approach to the situation; i used a pair of soft-jaw multi-grips to hold the starter cup and a ratchet to undo the nut. I couldnt get my hands on any Penetrene but used a heavy-duty Inox spray which worked a treat. I think i got pretty lucky because the flywheel came off pretty easily, without the use of a extractor. I didnt get a chance to take photos because i didnt have a lot of time to work with. Im pretty sure i'll rebuild the engine again in the not to distant future (i'm modifying the engine for a mini bike) and i'll photograph the process then

As the flywheel is on a keyed parallel shaft the only reason it would not come off easily would be rust. An issue you would not have if the motor is horizontally mounted.

You could have used a variation on the rope trick, the bit of wood trick and just loosely reassembled the head etc.



I would appreciate if you could put up pics and info on the clutch setup. And of the bike itself.

Yeah no problem, i was thinking of making a thread for the build and i can include such photos. I'll make a thread and post some photos up later on this afternoon or tonight

This thread is complete, since the flywheel has been removed. I will now lock it - if anyone needs to post to it, just PM a moderator.