Dear All

I have been having problems starting the bike recently after I ran around on full choke the other day out of beginners stupidity. The bike backfired a lot and then just stopped. It normally starts first time but yesterday taking it to a bike show it took a good dozen plus kicks to start even after a new spark plug change.

I was recommended to lower the carb needle by a friend to solve the new starting problem but after a dozen or so kicks the kick start stopped returning by itself, I presume the spring has broken and the bike didn't start either.

I was wondering if anyone can let me know if I need to drain the oil from the bike before I remove the side cover to gain access to the return spring. And any good ideas on why the bike that used to be a great first kick starter will not now would be welcome.

Regards

Stuart

email (option): deepsea@vol.net

yes you need to drain the oil before removing the cover.

The drain plug for the gearbox is located under the box and has a hexagon head...

You'll probably need a new outer cover gasket as well.

Accessing the bolts/nuts that retain the outer cover (located at the back of the inner cover where it projects forward towards the front of the bike from the gearbox case) can be very fiddly and you may need to remove one of the oil pipes from the engine to get at them...The outer pipe is the return pipe and it will have very little oil in it so you don't need to drain the oil tank before removing that one if needed...You will need to drain the tank before removing the feed pipe but that shouldn't be necessary..

You'll need to remove the gear lever and the large clip that retains the gear change indicator plate to get the cover off...You do not need to remove the smaller clip that locates in a groove in the splined shaft the lever fits to...

When refilling the box with oil after the job is completed you will find you won't get the recommended amount of oil (a pint) into the box..In practice it will be nearer 3/4 pint...Just fill the box carefully until the oil appears in the filler spout, that will do it...Use SAE 40 engine oil for the box...Ian

email (option): ian@wright52.plus.com

Dear Roy & Ian

Many thanks for all the detailed information, greatly appreciated. I will be in Melbourne next week and there is a classic bike spares shop so I will pick up a new spring and a set of gaskets while I am there. after that is changed I can get started on trying to solve the problematic starting.

Regards

Stuart

email (option): deepsea@vol.net

Also have a look at the Technical Section of the website: 'Gearbox work'; there is a useful modification of those fiddly bolts and nuts. One remark: use Loctite to secure the 1/4" end of the studs, to prevent them unscrewing instead of the nuts....

G'day Stuart,

In regards to your starting issue if the bike was running fine prior to you running it with the choke on, I would suspect dirt clogging the pilot jet or pilot outlet. Altering the needle height will not effect starting as the needle only governs 1/4 to 3/4 throttle openings also be cautious about lowering the needle as this will weaken the mixture in this range, increasing the chance of overheating (seizing).

Hope this helps.

PS. Where was the bike show?

Dear All

Many thanks to everyone for all the useful tips, its all greatly appreciated.

I have also noticed that the coating on the inside of my tank has deteriorated and flaking off I have a feeling parts of this may be working their way into the carb. I really need to just get on with the complete strip down and restoration rather that trying to fix the minor issues at hand.

Matty the bike show was in Hong Kong and my bike was entered into the pre war section, one of only 4 bikes in Hong Kong that slotted into that category, and was the only one running, the rest including another WM20 are all clapped out, one BSA didn't have any bolts it was held together with cable ties.

There are only 2 WM20's in Hong Kong but the guy whom owns the other one has no intention of getting it running he just keeps it for a display item at the shows, I have a feeling that when I have restored mine back to military colours his bike will then take a back seat at the functions.

Regards

Stuart

email (option): deepsea@vol.net

All power to you Stuart, It can't be easy doing a resto on a Brit bike in Honk Kong!!!
If you can beat that cable tie guy next time I think we'ed all be happy.

With the gearbox cover off might well be worth changing the kick start stop rubber.

Ian..