19 replies [Last post]
Fixfocus
Fixfocus's picture
 Offline
Stockholm, Sweden
Joined: 05/18/2015
Posts: 14

Fellow bikers, I have a BMW R60, 1957, with too much axial play on left intake rocker arm assembly, 0.3 mm. The whole assembly seems to be pressed together, nothing is loose as on later BMW models. Is it possible to press them togehter ever so little to minimize the gap?
The contact surface on the rocker is also a little pitted. Do I need to worry?

  • rocker.jpg
  • rocker_2.jpg
  • rocker_3.jpg
Daves79x
Daves79x's picture
 Offline
VBMWMO #9030
Joined: 08/09/2015
Posts: 251
Yes

Yes, you press the ends to get the sideplay you want. Barrington calls for just enough sideplay for 'oil clearance', which isn't much. I set mine with just a little noticeable play. You have to watch and maintain your rocker arm centering on the valve stem when you do this, and it takes some trial and error. Others here with far more experience will likely weigh in.

Dave

__________________

Dave

Fixfocus
Fixfocus's picture
 Offline
Stockholm, Sweden
Joined: 05/18/2015
Posts: 14
Thank You Dave for your

Thank You Dave for your reply. What method did you use to adjust the play?

808Airhead
808Airhead's picture
 Offline
VBMWMO #7677
Joined: 08/05/2009
Posts: 998
You can use a c-clamp with 2

You can use a c-clamp with 2 sockets on each end to press them together. It is a balance where you want to close up the clearance,but not bind the head bolts which will throw off your tq. readings. I install the rockers with the bolts spun all the way down,but not tightened,then clamp the rockers down,then tq. the heads. If you tighten them too much,don't fret, a light tap with a brass hammer will open them back up. As for the pitted rocker,you can dress that and be fine. I did that to my rockers (they had a small edge worn in) and this allows for accurate valve adjustment since you will have a smooth surface.

__________________

Thomas M.
R69s - R60/2 - R67/2 - R51/3

schrader7032
schrader7032's picture
 Offline
VBMWMO #7032
San Antonio, TX
Joined: 10/27/2006
Posts: 6327
I thought the tips of the

I thought the tips of the rocker arms had some kind of special treatment to them. I know the surface of the cam followers do. If there's a hardened surface, won't filing them remove that treatment, subjecting them to much more rapid wear? Admittedly the pit doesn't look good and might also do damage to the top of the pushrod. But just wondered about the rocker arms.

__________________

Kurt in S.A.
'78 R100/7 '69 R69S '52 R25/2

Fixfocus
Fixfocus's picture
 Offline
Stockholm, Sweden
Joined: 05/18/2015
Posts: 14
Thanks for all good advice!

Thanks for all good advice! Now, do I dare grind the surface on the rocker arm or not? Is there a hardened surface on it that will be ruined?

808Airhead
808Airhead's picture
 Offline
VBMWMO #7677
Joined: 08/05/2009
Posts: 998
I just dress them,it takes

I just dress them,it takes very little off,had no problems,and I actually ride my old bikes.

__________________

Thomas M.
R69s - R60/2 - R67/2 - R51/3

schrader7032
schrader7032's picture
 Offline
VBMWMO #7032
San Antonio, TX
Joined: 10/27/2006
Posts: 6327
In Fixfocus' case, it looks

In Fixfocus' case, it looks like a deeper pit, almost a bit of a flake. I suppose you really have to do something about it...that may cause contact damage with the top of the valve stem. You can try dressing it, running it for several thousand miles, take it out to assess how it's holding up. Then decide what to do long term.

__________________

Kurt in S.A.
'78 R100/7 '69 R69S '52 R25/2

Daves79x
Daves79x's picture
 Offline
VBMWMO #9030
Joined: 08/09/2015
Posts: 251
Available

The rocker arm are still available new, approx. $75 each US.

Dave

__________________

Dave

Fixfocus
Fixfocus's picture
 Offline
Stockholm, Sweden
Joined: 05/18/2015
Posts: 14
Dave, where did you find the

Dave,
where did you find the new rocker arms, what company?
Best,
/
Mikael

Daves79x
Daves79x's picture
 Offline
VBMWMO #9030
Joined: 08/09/2015
Posts: 251
Link
__________________

Dave

Fixfocus
Fixfocus's picture
 Offline
Stockholm, Sweden
Joined: 05/18/2015
Posts: 14
Thanks all again! I dressed

Thanks all again!
I dressed the contact surface on the rocker arm and it turned out to be real easy - it didn't´take much work to get rid of the pitting.
As for the excessive play on the rocker arms: I put the assembly in av vise, put sockets on each side and a little heat on the brackets to make them expand. I really thin blade from the feeler gauge inserted so as not to press it all together. Worked really well.

Now I am going to start the bike, check the ignition and start adjusting the carburettors. My ignition is electronic (EZA-4 from Ulis Motorradladen). I believe pulling one spark plug hat off is not so good for the electronics. Can I just unscrew one spark plug and with the hat on put it on top of the cylinder?
/
Mikael

  • dressed_rockerarm.jpg
  • adjusted_play.jpg
Daves79x
Daves79x's picture
 Offline
VBMWMO #9030
Joined: 08/09/2015
Posts: 251
Just Make Sure

Good for you! Just make sure your followers are centered on the valve stem. The ends of the rocker arm rarely press together evenly and that's where the trial and error comes in. You can shift the whole assembly a wee bit for final centering before torquing them down.

Dave

__________________

Dave

schrader7032
schrader7032's picture
 Offline
VBMWMO #7032
San Antonio, TX
Joined: 10/27/2006
Posts: 6327
Mikael - Do not pull the

Mikael -

Do not pull the spark plug cap off of a running engine. On the /2 bikes, there is a safety gap in the magneto area that should shunt the spark to ground, but it is considered not a good thing to trust. What you need to do is find an appropriate piece of threaded rod maybe 3 inches long and screw an extra spark plug nipple onto one end. These nipples usually come with brand new plugs, but have to be removed since our spark plug caps require just the bit of rod to be exposed. Screw the nipple onto the spark plug and then plug the cap into the other end of the threaded rod. Do this for both sides.

Now, to adjust the carbs, you want to short one cylinder. Take a long plastic-handled screwdriver, put the blade of the screwdriver on the engine fins, and then swivel the shank of the screwdriver onto the exposed portion of the threaded rod. You might want to practice this before you start the engine. By making firm contact with the screwdriver on the engine and the rod, you will allow the spark energy to go to ground. You can see how the other cylinder runs on its own. Release the screwdriver, make your adjustments to the other cylinder, and retry the shorting and confirm the new settings. Repeat for the other cylinder.

__________________

Kurt in S.A.
'78 R100/7 '69 R69S '52 R25/2

wa1nca
wa1nca's picture
 Offline
VBMWMO #8374
Ashfield Ma.
Joined: 09/27/2012
Posts: 305
Do not pull the spark plug cap off

You will damage your electronic ignition module or kill your coil

  • dsc04051.jpg
  • dsc04045.jpg
  • dsc04049.jpg
__________________

Tommy Byrnes
54 R51/3 55 R50 64 R27 68 R69US 68 Sears Allstate 250 (Puch)

312Icarus
312Icarus's picture
 Offline
Joined: 07/15/2016
Posts: 276
Is the dog's name

Is the dog's name "Sparky".

(I used to have that same Pioneer stereo, or is it a Marantz?)

Icarus

Fixfocus
Fixfocus's picture
 Offline
Stockholm, Sweden
Joined: 05/18/2015
Posts: 14
Tommy and Kurt, thanks for

Tommy and Kurt, thanks for the pictures and instructions!
I will make my own tools for this today. Smart idea using starter cables/clamps, but I think I will go for the screwdriver method. I will let you know the outcoming of my efforts.
/
Mikael

wa1nca
wa1nca's picture
 Offline
VBMWMO #8374
Ashfield Ma.
Joined: 09/27/2012
Posts: 305
the dog's name is Jet

Pioneer SX680

Mikael
I find it difficult to short out the opposite cylinder while trying to adjust the carb on the other side
PS
It is most important like Kurt says with the screwdriver and if using a shorting jumper that the screwdriver or the jumper should be grounded 1st and then to the spark plug lead

You will not get a shock if the jumper is connected to ground 1st
If you connect the jumper 1st to the spark plug your body will now be the ground path for the spark you will feel it

Tommy

__________________

Tommy Byrnes
54 R51/3 55 R50 64 R27 68 R69US 68 Sears Allstate 250 (Puch)

Fixfocus
Fixfocus's picture
 Offline
Stockholm, Sweden
Joined: 05/18/2015
Posts: 14
Finally!

The bike now runs like a charm. The reason my carburettors (or at least one of them) coughed at idle I now think was due to dirt in the idle jet. I cleaned everything and put fuel filters on the fuel lines, and this hopefully takes care of that. Then I tried to sync my carburettors using the spark plug short-cut method, i e listen to one cylinder at the time. It got better, but not good enough, so I ordered two Empi Sync adjusting tools. Wow, that made the difference! I managed to adjust the idle somewhat ok without the tools, but once the throttle wires got some tension to them, the sync went way off. But by ear and the feel of it I thought it was ok. But with the tools, the adjustment was made in a few seconds. Now the bike runs beautifully, with very good throttle response. Now it is time to take it for the long runs. Thank you all for all the help here on internet!

  • img_7536.jpg
  • img_7539.jpg
wa1nca
wa1nca's picture
 Offline
VBMWMO #8374
Ashfield Ma.
Joined: 09/27/2012
Posts: 305
Very nice bike

Enjoy

Tommy

__________________

Tommy Byrnes
54 R51/3 55 R50 64 R27 68 R69US 68 Sears Allstate 250 (Puch)

Comment viewing options

Select your preferred way to display the comments and click "Save settings" to activate your changes.