ATCO COMMODORE B20 20"

Hello,

It sounds as though the recoil start could be slipping but a couple of photos to help identify the engine and the recoil components would be helpful.

Two possibilities.

The pawls may be riding out of the cup which is bolted to the flywheel. You can possibly tell if that is the case by looking at the rim of the cup: if it's chewed up a bit that is possibly what's happening. If that is the case, remove the plastic cowling containing the recoil starter,slacken the hex head screws holding the metal engine cowling and push it in towards the block and re tighten the screws. If that's not enough try removing the cup from the flywheel and refitting it with a washer around each fixing screw between it and the flywheel.

Otherwise, although the pawls appear to be extending when you pull the rope they may not be coming out quite enough. It is an inertia starter which relies on the washers and spring around the centre pivot to grip the actuator bar and resist turning and in so doing force the pawls outwards. It should be dry and not lubricated to supply sufficient inertia but if everything is a bit worn and slack you may need to try different thicknesses of washer to supply sufficient grip. If the split pin is worn even just fitting a new pin is enough.

Thanks all.....

Wristy, the washers did the trick 95%  , would have been better if I could have got 2 on each bolt (may try and file another 2 down a bit).

Looks like it's been a problem in the past the split pin replaced with a bit of bent wire so someone's been having a fiddle. (got a match box somewhere with loads in and can't find it).

Wish I could drop pics on here easier..............

www.dropbox.com/s/oryrkkmca6vse65/IMG_3773.JPG?dl=0

www.dropbox.com/s/x0gz6udte6u3szv/IMG_3774.JPG?dl=0

Think that two washers may cause bother of their own as from your images it looks as though the cup is already rubbing on the starter pulley so it may be a good idea to try and find a cup in better condition . Also, if  the pulley is wobbling on its centre pivot the pawls will be tilted and not engaging it square. 

Also, that design where the starter mechanism is mounted on the outer plastic shroud is prone to flexing  which, together with general wear and tear will be contributing to your problem. It's probably a matter of trying to obtain the optimum operation with what you have rather than the perfect solution - if that makes sense!

The washer bodge may work in the short term, but in the long term, he is going to need a new starter pulley. If you look closely at the second picture, you can clearly see that it is damaged where the clutch bar is supposed to stop. This will lead to the pawls not throwing out fully, in fact they may actually go in slightly.

All in all, that type of starter was probably the worst starter they ever made, it was nothing but trouble, especially if it was used with the extended starter cord. The best plan would be to obtain and fit an earlier starter and cup.

I totally agree that the Commodore starter built into the outer cowl was a pretty horrible affair but the previous stand alone plastic cased one was not much better. It was down hill all the way from the original cast alloy cased one.

That said,  a lot of starter problems are self inflicted  and result either from engines past their best or in need of maintenance or operators who snatch at the rope and then let go of it. I've lost count of the number of times that I showed customers how to gently pull the rope to engage the pawls  followed by a steady pull and return,  only to then see them snatch at it.

Compared with that horrible greenish one piece starter come airshroud, the earlier plastic starter was a delight, but as you say the best was the alloy starter.

Been there, done that, when it comes to showing users how to start engines, they never listened, the worst were the ones that used to snatch the rope out with great force and then just let go of it. They were the ones that used to complain about how the starters kept breaking and wanted them repairing under warranty.

I have to admit I was doing a little bit of the snatching after having 2 more modern rotary style mowers.I think they must have been designed better and no plastic flexing about. I could just keep pulling until it fired no problem, didn't ever let go of the handle though.

Now after seeing the pawl work and your advice, i'm pulling to engage it  like an old 4 stroke motor bike engine your about to kick over and getting it in the right compression position to start it it.

It does now start much easier.