HELP! Replacing Rocker Box

[Nickfrank]

I'm several hours into trying unsuccessfully to refit the rocker box on my Huntmaster after replacing the head gasket. It seems physically impossible to get the box over the push rods so one intake and one exhaust sits either side. The exhaust pushrods are just too high to be separated so one falls each side of the rocker box central flange.
I have tried everything - backwards, forwards and sideways. Have removed the engine stays thinking that might help - nada.
And knowing I have to go through all this again to retorque the head makes me wish sometimes that I'd taken a pass on buying the bike.
Does anyone have any tips? I have the comb to keep the pushrods in line but that's not the problem, at least not until I make sure they sit properly in the rocker arm cups. I'm assuming the pushrods must be in place before fitting the rocker box vs trying to install them through the inspection hole after?

Many thanks for any help you can provide. I'm at my wits end.

[Steven.Carter]

Have you left the inspection cap in place on top of the rocker box. That will stop it going on. I normally turn the engine over till the pushrods are as low as they can be. Have you got the combe that helps to align the rods in the correct place?

Steve

[Nickfrank]

Have done all that Steve but it's still defeating me. I can physically see why it won't go on but I'm at a loss as to what to do about it. I've managed to get intake and exhaust pushrods ok on one side of the flange and the intake pushrod on the other side but it's the other exhaust that cannot be moved over without raising the box another 1/8" or 1/4" and there is no clearance to do that. I was hoping someone had a tried and true method - a certain way of feeding the box in under the frame or something. It seems unbelievable to me that the bike would have been designed in such a way as to make changing the head gasket so complex.

[Steven.Carter]

Hope this helps
Here's the procedure I take.
make sure the tappet adjusters are wound out completely

I use a combe to help getting the pushrods located

Make sure that the exhaust rods are as low as possible and feed the rocker box over the rods as the next two pictures

Make sure the rods are leaning against the combe then lift each rocker into its cup. Then tighten down the adjuster onto the valve. Don't forget that one tappet adjuster will tightening down further because that valve would be open. When the rocker box is bolted down properly you can then get the tappets adjusted correctly.

[BUNNERS]

Nick
I know what you are going through, fortunately Steve does not live far from me and he answered my call for help, what had taken me best part of a day to achieve nothing he did it in under 5 minuets so he knows what he is talking about. the comb is an important item as is I believe feeding the rocker box in at 90deg at a slight angle, to the head as in picture three.

[john.whiting]

That "comb" is a BSA service tool,and a thin bladed kitchen knife also works as well.One of my earliest memories of motorbikes is the metallic clink of the A10 pushrods falling out of the rockers.Regards John.

[Nickfrank]

Steve, success!!!!!!!!!!! If you can believe it, I had the rocker box on 15 minutes after I sent you the last note. It was all due to your photo #3 - how to guide the box over the tops of the pushrods. My issue was primarly that, not getting the pushrods in the rocker arm cups though it took me a bit of dicking around to get them positioned properly. I haven't tightened anything down yet but I'm sure that things are in their proper places.
Now when I remove it again (arrrrgggg!!!) to retorque the head, I'll know how to put the bloody thing back on again. I will post this reply to the forum once I get back into the website. Perhaps it will help some other poor schmuck avoid what we went through.

Cheers!
Nick

[Steven.Carter]

I'm good for something then

[BUNNERS]

A picture is worth a thousand words. who was it said that?

[roger.attwood]

I've not done this before, but heard many stories about it. It's the next job on my Huntmaster, so there's timing for you.