Rocker box

[Sunbeam]

Have any members experienced the same problem with their rocker box or have I overlooked something? After fitting new pushrods in my RGS engine I'm finding it very difficult refitting the 2 rear sleeve nuts. First attempt, all pushrods located correctly, rocker box bolted down nice and flat. Then found  there was no room to start the new sleeve nuts on rear studs.

I decided to slacken all the rocker box bolts and lift the box slightly so that I could get the sleeve nuts started on the rear studs. Pushrods then had to be reset again using the comb. Now found that the sleeve nuts are picking up in the head when screwed halfway home. Decided to walk away and leave things as I did not want to damage cyclinder head. Have thought about removing the 2 front studs to give a bit of fore / aft movement in the box.

Howard.

[bsa-bill]

Yes they are fiddy.
I Think you have went the right way, leave all other studs slack until you get those started, as for picking up on the head are you using the proper washers, those two studs use a very thick washer, available most dealers

[Sunbeam]

Thanks for the reply Bill. The Haynes manual does not tell you that the sleeve nuts cannot be fitted after the rocker box is in position! Am I right in saying that unscrewing the front & rear studs slightly is the way to go. I bought new sleeve nuts with thick washers and the sleeve nut pushed into the head ok without the stud. But on refitting the rocker box and tightening the sleeve nut, its seems that the sleeve part is catching inside the stud hole. Did not want to crack anything, have learnt the hard way in the past and made a cup of tea and thought about the problem!!

Howard.

[bsa-bill]

Yep that's it Howard, get everything else just started then wiggle the box about to get the extended nuts started.
If you can remember also to put the carb on the head (with top on) before you put the head it save a bit of hassle too

[Sunbeam]

Thanks for the advice Bill, I'll slacken all the studs off. 

Howard.

[RichardL]

Then found  there was no room to start the new sleeve nuts on rear studs.

I take it from the above quote that you can't fit the sleeve nut between the stud and the top fin of the barrel. Is that correct? If so, I'm wondering if you have the correct length studs in place and that they are landed home in the rocker box. The correct length should be 1-7/8" (67-1117 STUD - ROCKER B0X (ALI HEAD) 5/16" CEI/WHIT X 1 7/8", courtesy Burton Bike Bits).
The next things I wonder about are:

• is the stud perpendicular to the rocker box;
• is it in the original hole, or has the hole has been reworked (like with a helicoil).

It is a very close fit for the sleeve nut through the head to catch the stud and any off center of the stud would be a problem.

Richard L.

[Sunbeam]

Hi Richard, thanks for the reply. Rear rocker box studs could be the wrong length, just over 1/2 inch of thread showing through the head and unable to get sleeve nuts on. They could also be off centre giving the tightening problem. Previous owner must have spent a lot of money on the RGS engine, thread inserts and stainless stud / bolts everywhere. Think I will remove rocker box yet again and check the length of the rear studs with your measurement. Glad I used grease instead of gasket sealant!

Howard.

[RichardL]

They, most definately, should not be protruding from the head that far. In fact, by recollection, I don't think they protrude at all.

Richard L. 

[RichardL]

By the way, in case manipulating the front nuts is making you crazy, the handle end of the comb makes a good nut supporter (this post really sounds bad) while getting them started on the studs. If you put a bit of thick grease on it you shouldn't have to be recovering the nuts from the floor or top of the dynamo, having dropped said nuts fifteen times.

Richard L.

[Sunbeam]

Thanks for info Richard, now looks like previous owner or dealer fitted wrong length rear studs. Bought the s/s sleeve nuts & washers from Brian at Lightning spares...excellent service. Will now contact them for new front & rear studs Monday. Good idea of yours to use the pushrod comb to support the front stud nuts.


Howard.

[bsa-bill]

agree with Richard you should not see any of the stud, otherwise why sleeve nuts

[Sunbeam]

Thanks Bill. Going with a new set of studs which i'll leave slightly loose as you recommended until the sleeve nuts go in ok.

Howard.

[muskrat]

G'day Sunbeam,
                      I don't think Bill meant leaving the STUDS loose, they have to be screwed home into the rocker box before fitting. I'd say he meant the 5 bolts.
 I'd say the longer studs were fitted to use external nuts instead of the sleeve nuts. It would be impossible to fit the box on with them fitted to the box with the motor in the frame. Would have to drop the stud into the head, loose fit the box, screw in stud, finish fit box then put the nuts on. Would be a nightmare to get off.
Cheers

[bsa-bill]

Yes Howard Musky is right that's what I meant, studs should be tight at all times, just get the bolts and front nuts started so that the box can be moved around a bit to let the sleeve nuts get hold of a thread.
just a thought ( this has caught us all out at some time ) you have got all the tappets slackened off so that there is no pressure from the valves holding the box off the head.

[Sunbeam]

Hi muskrat & Bill.
This all goes back to when I removed the rocker box to retighten the cylinder head and fit new pushrods. Had great difficulty in removing the rocker box without damaging top tube paint. Noticed that both rear rocker box studs were finger tight so I unscrewed them allowing them to drop onto the head and that both sleeve nuts had been shortened by previous owner or the dealer who I got the bike off. I did'nt know the correct length of a sleeve nut until I got new ones from Lightning Spares (thick washers were also missing). Thanks to all for the helpful advice and i'll leave the 5 bolts slightly loose to aid fitting the sleeve nuts.

Howard.