Ticking sound coming from head

[boxertwinjeff]

Well I'm not what I'd call the Mechanically minded type, but I'd like to have a go
at affecting the repair to the right head of my R75 if it's not too complicated.
For sometime now, the right head has been making a prenounced ticking sound.
Everyone thats listened to it has said it won't do any damage, maybe just get louder.
As funds have been tight, I've hesitated taking it to a workshop.
What would the cause of the ticking sound be, tappets?
Would the repair job be something I could tackle myself ?, and what parts would be
needed, also what would they cost ?,. in Australia that is. Cheers Jeff.

[ME 109]

Jeff, much easier if you're shown how to do it, (adjust valves) rather than told how......
Got a manual?
It should cost you nothing to do it yourself, unless of course you set them incorrectly and burn a valve out

A good workshop should do it in less than 1/2 hour.

Maybe, we could lure some of those blokes wasting an awful lot of time on the speakeasy over here. I'm sure they could find time to write you a thesis on valve adjustment.

[chasbmw]

On a r75/5, the sound could easily be a combination of too loose tappets and too much 'up and down ' movement of the rocker arms. Adjustment is not too difficult, various descriptions on the web, but remember that BMW improved the rocker arms a couple of times after your bike before finalizing the design in the mid 80s.

Charles

[ME 109]

Excellent pics linked to your signature Charles, are they old pics or is that someone else?

Edit, Ah! pics of your Australian trip as well, old pics. Cool.

[boxertwinjeff]

With just over 105,000kms ( 60,000 miles) on the clock, would you expect the rocker arm and/or
the tappets need anything more but an adjustment?

[chasbmw]

well yes....................I might expect to see wear on the heel of the rocker arm that bears upon the valve. i think that the original /5 rockers ran in a simple bushing, which would likely to wear more than the needle bearings used from /6 onwards.

I would check and adjust and see if simple adjustment makes the problem go away.

[Garnet]

Charles is right about checking the up and down movement of the rocker as well as the condition of the rocker bushings at the same time as adjusting the valves.

If you google BMW airhead valve adjustment you'll get lots of good reading material, but try and find articles on the /5.

If you decide to repalce the rocker bushings, which are not expensive, look at the rocker shafts while everything is apart. You will see some visable wear on the head side or preasure side of the shaft. If no one has been in there before you can rotate the shaft one half turn and have a smooth surface for the new bushing to turn on when under load.

Replaceing the bushings and checking the shafts and setting it all up nice shouldn't take much more than a couple of hours and is very strait forward one you are in there and see it.

One more thing that is a bit of a trick. You will see that the rocker blocks that the headbolts go through are not centered on anything but the headbolt and the whole assembly can be moved around a lot. That is how you adjust the endplay of the rocker arm. What can happen is, a rocker assembly can move over far enough so that the pushrod can conatact the inside of it's port in the head, when the valve is fully open, causing a ticking sound on a perfectly adjusted valve.

Once you are fully assembled, slowly rotate the engine so that that valve opens fully. Then look down the pushrod or take a very small wire and make sure there is a gap all around the pushrod. If you are happy, then proceed with the head torqueing and final valve adjustment.

I find that my /5s are happy (quiet) with the valves a tiny bit tighter than spec. You just need to check them more often.

[vanzen]

Duane Ausherman shares his excellent site on the care and feeding of the old airhead.
His page, BMW motorcycle valve adjustment procedures,
should get you headed in the right direction.

Once the valves are adjusted, check the adjustment periodically
as an assurance that your exhaust valves or seats aren't going away ...
At 60K miles, if original, I'd suspect that the guides are getting a bit sloppy, too.

Use Duane's site, plus your BMW manual, plus perhaps a Clymer or Haynes,
and all the misinformation you can extrapolate from the inmates here
to get that /5 into good nick !

[SteveD]

Certainly, the place to start is in your garage. It's a relatively simple thing to do.

Finding tdc on the correct stroke might be annoying when you're not familiar, but taking it slowly will see you getting there soon enough.

The clearances for the /5 is 0.15 mm for the intake and 0.2 mm for the exhaust. Check what they are before you begin, and maybe adjust them a tad tighter, eg 0.12mm/0.18mm. It won't hurt, and if they're quieter, then you're on the money.

Remember though, they do make noise, and you should expect to hear some tappeting happening..

[boxertwinjeff]

Thanks for all your input guys, will have a looksee inside when I finally get
some free time from my work.