Author Topic: Push rod tips  (Read 414 times)

Online Greybeard

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Push rod tips
« on: 01.06. 2018 11:31 »
From Micky Bodill on Facebook group 'British Motorcycle Mechanics'

'For putting the pushrods back I attach a soft aluminium wire hook loosely to each rod and using a dentist's mirror jiggle them into the rocker. Do it at top dead centre, one set of valves closed the other on overlap.
The 'comb' tends to scuff any sealant you are using. The wire being soft can be pulled out when finished.'



I'm deffo going to try this idea!

Online Greybeard

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Re: Push rod tip
« Reply #1 on: 11.06. 2018 15:15 »
I now feel that I can give good advice about the horrible job of getting your pushrods in place:

You will need:
A small but bright torch, (see pic).
Rubber bands
Soft aluminium wire, such as garden tie wire. Cut off four lengths about 6 to 8" long

The cylinder head is already fitted and torqued down. Whatever sealant and gaskets you want are already applied.

1) Squirt oil into the pushrod cups in the cam followers, (bottom of the pushrod tunnel).

2) Place the short pushrods in the outer cam follower cups and the longer rods in the inner cups, making sure they are properly seated. The oil should help to keep the pushrods in place while they are being located in the rocker cups.

3) Rotate the engine until all four pushrods are approximately level. This is easily done by removing the spark plugs, putting the bike in fourth gear and turning the back wheel by hand.

4) In the rocker box, unscrew all tappet adjusters until they are flush with the rocker face.

5) Put elastic bands over the top of the rocker box and around each pair of rockers, (see pic)

6) Bend the end of pieces of soft wire around each pushrod, (See pic)

7) Carefully bring the rocker box in from the front of the bike, making sure that a pair of pushrods go into each side of the box.

8 ) With the rocker box resting on the pushrod locating wires shine a bright light into the rear of the rocker box, (this may need another pair of hands or the torch fixed in place under the frame top tube) and lower your line of vision so you can see below the inlet rocker shaft. In this position, you should be able to see each pair of rocker cups. The pushrods are likely to be pretty close to the rocker cups but use the wires to move them as required slightly to locate the cups. You may need to depress a rocker against the pull of the elastic band to lift the cup and capture the pushrod tip.

9) Even when you have all four pushrods located, do not remove the elastic bands; the tappet adjusters have so much free movement it is still possible to displace a pushrod from a cup!

10) When you are sure that the pushrods are located, gently pull out the wires, one by one. Keep upward pressure on the adjuster end of the rocker to make sure the pushrod stays in place.

11) Settle the rocker box with your hand

12) Loosely tighten the box bolts. Slowly rotate the engine to check that the valves are all opening and closing properly.

13) Tighten rocker box bolts evenly.

14) Adjust tappets.

15) Cut off elastic bands

Offline RoyC

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Re: Push rod tip
« Reply #2 on: 11.06. 2018 16:35 »
This should be made a sticky.
My bike is a 1958 A7SS
Staffordshire UK

Offline muskrat

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Re: Push rod tip
« Reply #3 on: 11.06. 2018 20:38 »
G'day GB.
That's pretty much how I do it, bar the soft wire. I still use the comb and goo as per burger's method. I also use removable studs to locate the comb and lower the box square. 9/10 all goes straight in, on occasion the inlets miss and need persuasion with a bent pick.
I originally used the rubber bands as I shim my rocker shafts instead of the thrust springs to hold the cups down and stop the rockers from flopping. With the thrust springs the cups should stay down but the rubber bands are good insurance.
Well done mate.
Cheers
'51 A7 plunger, '57 A7SS now A10CR,  '83 CB1100F, 88 FXST .
Australia
Muskys Plunger A7