Push rod fun

[Greybeard]

If you ever meet the ghost of whoever designed the rocker box on these bikes will you give him a good kicking please.
Also same applies to the bloke who gave us that crappy comb device!

[BSA500]

Add floating cranks to that list please

[RichardL]

If you ever meet the ghost of whoever designed the rocker box on these bikes will you give him a good kicking please.
Also same applies to the bloke who gave us that crappy comb device!

I just remounted my rocker box with the usual expectation that it was going to be a pain, but it turned out not that bad. The new thing I'm doing (new for me, at least) is to hold the ends of all four rockers in the up position by using rubber bands pulled back to one of the 4 long bolts. This way, once the comb aligns the pushrods with the cups and the box is pushed down, the pushrod ends stay in the cups. I think that's a fair part of the battle. I don't think it is any kind of news that putting gasket sealer on both sides of the Bid-D gasket and sticking it to the box rather than the head limits the schmearing of sealer with the comb.

Richard L.

[muskrat]

I do the same Richard. As I replace the end thrust springs with shims the rockers flop down. Elastic bands keep them up. the ex rods go straight in, it's the inlets that give problems. A piece of hooked wire helps them into the cup and the elastic bands hold them there.
Cheers

[Tone]

Oh no lve got that to come, if I can find the blinking comb.

[muskrat]

It's not too bad Tone. If I haven't got them in by the 6th beer I come back to it after another 6.
Cheers

[Greybeard]

If the comb would stay put it would help. I might try glueing it in place with gasket cement next time.

I thought I had the pushrods and rockers all located but realised that one of the exhaust pushrods was holding up the edge of the rocker cup; loosened off again; got that one sorted only for the other one to do the same thing!! I was trying to hold a torch while also manipulating a hooky wire and rocker arm. SUCH FUN!

[Rocket Racer]

I concur with Muskey and Richard,

• use rubber bands from old inner tubes,
• do it when your fresh, not tired and stressed
• a bit of grease in the rocker cups

with steel pushrods, I use the comb, with alloy ones I find I don't need it.

take out the plugs and carefully rotate the motor(using backwheel in gear) to check they are seated

[Rocket Racer]

If you ever meet the ghost of whoever designed the rocker box on these bikes will you give him a good kicking please.
Also same applies to the bloke who gave us that crappy comb device!

In their defence these twin motors designed in the forties were among the earlier enclosed rocker box design twins and better than the comparable triumph (too many bits to leak) and as bad as norton (really fiddly as the rocker box is cast in) . Certainly from the A7/10 came the A50/65 head which is far superior for assembly, so at least BSA learnt something, whereas norton and triumph twin heads were never improved upon due to lack of finances.

Like all these motors, once you've done it a few times you develop strategies to do it.

[hdawson]

I thought the comb looked dodgy from the start.
I just use a bent coat hanger wire  to manipulate the pushrods into position and don't seem to have any trouble.
Using Peramatex blue (while giving a oil tight seal) I always worry that, when removing it, that swarf may end up somewhere in the guts that may cause trouble.
Should I just use a gasket and put up with a  bit of weep?

[bsa-bill]

I have longish slim fingers, I can reach in from front and back to place a pushrod.
Now that would lead you'd think to an ability to master a guitar - not yet by a long way

[mugwump]

I was given an endoscope as a b'day pressie and its one of those gadgets that you wonder how you got by before. I found it comforting to be able to ensure the rods were in their relative cups. And, I find the naturally magnetized end of a screwdriver perfect for lining up the tops of the rods into the rockers. It helps as well to have an Ariel h'master rocker-box!!

[Greybeard]

It helps as well to have an Ariel h'master rocker-box!!

Well if you are going to cheat I'm not playing!

[Greybeard]

I have longish slim fingers, I can reach in from front and back to place a pushrod.

Can I ask for your help next time? 

[Greybeard]

I can see the benefit of the tip to use rubber bands to hold the adjusters up and the cups down; I just keep forgetting to do it!!