OutdoorKing Repair Forum Forums Repairs and Maintenance Questions on Walk Behind Lawn Mower Frames Question On Scott Bonnar Cylinder Mowers My SB 45 resto has begun

Hi Greg, Its great to hear that it's all going well for you, please don't forget to post pics as you go along, as we all love to see them.

Tonights work involved installing the new Carbie gaskets and filter and cutting up the foam for the new air filter.

Here is some pics of the nights activities

Here is some other pics from

Update:

The ignition timing has now been done and the engine has been re-assembled. The spark is now a strong blue colour compared to the weak yellow colour that I had before the strip down which is now generated at a lot lower rpm than what was before. When looking at the electrical components I had found that the ignition lead had Sumitomo 1981 printed on it which means that it was a fair bet that the motor was made that year.

I have a question on the removal of the drive shaft key on the sprocket end. What methods have members on the group tried to get this key out. As I am wanting to repaint the drive shaft to be similar to what Deejays is but in black to match the FA130d starter.


Thanks in advance

-greg

The first question is whether it is a rectangular key or a Woodruff (half-moon) key. You use different methods for the two types.

Hi Greg, the key is a half-moon type, just give the area a good soaking with WD40 or CRC, grab a screw driver and hammer; now locate the tip of the blade low down on one end of the key and tap gently...it should slide up and out.

Been trying to do that all day yesterday with that woodruff key ! ;-) lol

I agree approximately with Deejay's prescription for removing a Woodruff key, but I always rock them first. That is, I tap downward, toward the center of the shaft, on one end of the key until it tilts. Then the adhesion between the shaft and key has been broken. I then tap longitudinally on the end of the key that is now raised well above the shaft, due to the tilting of the key. That is the right way to remove a Woodruff key, and the wrong way to remove a rectangular key, so you need to know which kind you have. Thanks Deejay.

Hi grumpy, now you've tweaked my interest mate, what is the correct method of removing a rectangular key?

Deejay, the first step, if there is any corrosion (which mainly means if the key is exposed to oxidation in the outside air, and isn't constantly wet with oil) is to soak it with penetrating oil. Then you need to break it loose, before removing it. These steps are the same as for a Woodruff key, but you break it loose in a different way: you apply a punch to the end of the key and tap it axially to slide it along the keyway. Often the objective is to get one end of the key to lift up in the keyway, so you can lever it out, but if the key is close to the end of the shaft, you may be able to just tap it and slide it off the end of the shaft. In practice you usually can't do this though, because there is a bearing behind the end of the key, right where you want to tap it from, so you are mainly trying to get it to rise up higher in the keyway. Then you can put something under it and lever it up and out.

If the key is right on the end of the shaft and the bearing is close to the key, you can use the bearing's inner ring as a pivot to lift the key. Instead of tapping the key along the keyway, you lower the free end of the punch and tap the end of the key upward. With one end of the key immovable against the inner ring of the bearing, it is usually easy to lift the key in this way. Of course you can use a tiny chisel to get underneath the free end of the key, but this requires lots of tiny chisels of different widths, and often scores the keyway, so it is a bit on the crude side.

Thanks for that grumpy, I have a funny feeling that someone will be looking for this thread when trying to remove a key,and won't be able to find it. Maybe it might be worth while posting both methods in the topic "Restoration, Tips and Queries" and locking it up, mate, What do you think?

Sounds like a good idea Deejay. Would you leave a copy here, or just move this part of the thread? I think I'd do the latter, but you're the communication guru (as well as being much more experienced in how this site works).

Yes grumpy, we would absolutely leave this thread in place, but could you please post both methods as a dedicated thread (such as "Woodruff and Rectangular Key Removal") in the "Restoration, Tips and Queries" topic and lock it up?
It could really come in handy, as it has done in this topic.
Thanks mate,

Done and posted, Deejay. Of course in my usual fashion I waxed loquacious and added some extra detail plus an anecdote.

Repainting the cowl