What a rotten way to spend Sunday afternoon

[a101960]

Normally I a man of infinite patience. But today my patience has been sorely tried. Bl**dy A10 **!!!********!! Anybody care to guess what it is I have wasted a whole afternoon doing? The Jobs done now, but oh how I hate that task. I suspect that many of you have experience a great deal of frustration doing this job. Some people claim to able to do it in ten minutes. For me it has never been less than an hour, and today was just plain tiresome
John

[Duncan R]

Rocker Box ?

[tombeau]

Push rods or pistons into the barrel?

[MG]

Cleaning and polishing?   

[a10gf]

Fixing a flat ?

[Beezageezauk]

Yeah,  I'll go with changing a tyre!!

Beezageezauk

[Briz]

Ignition timing?

[metalflake11]

It's got to be the pushrod locating problem!
Brazing rod, torch and the rocker box about 1/2" from seated works for me.

                                                            mf

[morris]

trying to get it started?

[a101960]

Rocker cover and pushrods. Unbelievable! I had the cover on and of so many times that I have lost count. Every time three of the push rods located correctly and one was dislodged, and always a different one to the time before. I used all methods The comb, hooked wire, and thin screw driver. Eventually the comb triumphed. I have to marvel at how it was done on the production line. Clearly a job you were given if you had upset the foreman. It really is an awful design. I agree timing is also a rotten job but that is not an exclusive BSA design problem. Any magneto equiped bike is problematic, but the A10 pushrod/ rocker cover is the spawn of the devil. Ah well tomorrow is another day. Who knows I might even get to go out for a ride.

John

[Briz]

Comb never really worked for me. Wipes all the hylomar off the gasket for one thing!
I guess if you were doing it all day every day you'd get a knack for it.
All the A10s I've built except the first, I've machined a hole in the top, or (on my last one) used an Ariel huntmaster rocker box, which has a hole.

[muskrat]

Next Olympic sport or a fun game at the next A7/10 BBQ. Would have to start early am and have flood light back up.
Cheers

[fido]

It is a very long time ago but I don't remember having a problem doing the pushrods on my A7SS. The job I hate the most is doing the ignition timing and that was just as bad on the A7SS, the B31 and the A7 longstroke. Actually it is a bit worse on the longstroke as it is auto advance. On the other 2 if it was a bit too advanced you could retard it on the lever.

[orabanda]

This job is a bit like sex; the more you do it, the better you get at it.

I have also had the occassional difficult experience, but generally these days it seems to only take 10 - 15 minutes.

One tip is to turn the engine over, so the exhaust cam lobes are at the bottom i.e; the two longest pushrods (exhaust) are level at the bottom of the stroke.

Check that the two studs hanging down at the front of the rocker box (one per exhaust valve), are no longer than necessary; just enough thread to get washer & nut on.

Richard

[KiwiGF]

Push rods engagement tips gleened from this site........back off all the rocker adjusters, fit elastic bands stretched over the rocker box cover to hold the rockers adjusters up and hence cause downward pressure on the rods. Turn the engine to make sure exhaust valves are both shut. FIt cover and push lightly down until all there is (elastic band) pressure on all the  rockers. One inlet valve will be open and the cover will not go down fully on that corner. Use a ruler or piece of wire to move the inlet rods so they engage propely in the rockers, feel they are engaged with your finger. Exhaust rods should almost always engage without help. When all rods are engaged do the rocker box nuts up a bit at a time double checking nothing is being forced/bent by making sure the rockers are free to move at all times. It can help to do the adjusters up  finger tight before tightening the cover nuts. Above applies to s/a engine. Sometimes takes 5 mins sometimes 15mins!