Metal on metal Knocking when trying to kick over after changing rocker gaskets

[KiwiGF]

Did you check the push rods didn’t get bent during the first install attempt? Just a thought…..they run pretty close to each other and if bent might touch, I have even heard of aluminium rods (being thicker), contacting each other so the clearance must be quite small.

Others may disagree but the tappet clearance is pretty generous on these bikes, considerings its all steel/iron. It can be safely reduced a bit to make things a bit quieter, but I would recommend checking the clearance more regularly if you try that, including when the engine is hot if possible.

[sean]

Hi guys just an update got an alignment tool and managed to fit all together well. I adjusted the tappets and it started second kick but there seems to be a tapping noise now could the tappets be making this noise? The noise does sound like it's coming more from the bottom than the top though.  Again any pointers would be great

without knowing the condition of the rest of the motor or hearing the noise would be hard to diagnose over the internet grab a garage type stethoscope and pin point the sound  ...there will always be some tappet noise ....good luck

[Jlad]

Thanks for the responses the engine ran perfectly without this sound  before i changed the gaskets so im sure its something i must be doing wrong i did check the rods were straight when I had them out again too. I will try and upload a video if adjusting the clearances again doesn't sort it.

[bikerboy]

Are you running it without the tank bolted on and no crash helmet, they always sound louder when you are next to them without a helmet on and no tank to baffle the noises

[Swarfcut]

 Sean suggested a garage stethoscope, but for the rest of us a crude listening stick (long handled screwdriver) is fine. But a word of caution, these air cooled motors are naturally noisy but don't get paranoid as you sample piston slap, magneto bearings timing gears etc going about their work.

 Any difference from the valve gear side to side should help locate the source but if it runs OK the other option is to set the tappets, treat with respect, wait and see. You can waste hours and find nothing. To quote the service manager... "They all do that, Sir."
 
Swarfy.

[Klaus]

Hello Jlad,
is this knocking at every tourn from the engine and is it only at the outlet side?
I had this phenomen on one of my enginges and it drive me crasy.
If this happend check the gear at the cam if it had come lose. Its only the space between the wodrofkey and the notch produce this knocking. This can also cause that the ignition gear come get lose.

cheers Klaus

[Worty]

For me, the simplest way initially is to remove the rocker inspection covers and the spark plugs.  Select 4th gear and turn the motor over slowly using the rear wheel.  Check to see all four valves are rocking, then increase the speed a bit to see if that makes any difference or you can hear a noise.  Check also to see if the tappets are not bashing the covers.  Also, a bright light down the plug hole will show whether the valves are opening or not (you can just see them).  If all of this is ok, then it's time to look elsewhere for the issue.

For reassembly of the push rods, I used Colsbeeza's 'comb clamped to cylinder head' approach.  I use elastic bands to keep the rockers AWAY from the push rods with the adjustment completely backed off.  When the head is nearly on (just enough to remove the comb and with pushrods correctly located in the comb), I gently remove the bands and move the rockers toward their adjustment position - then set gaps accordingly once all is in place and checked as above.  The logic is tha if the comb is secure, and the pushrods are in the correct places, then the rockers should just drop down on top of them.  Tried this a few times now and it seems to work very well.

[muskrat]

G'day Jake.
Another noise can be backlash in the timing gears at kicking/hand winding speed. Usually goes at running speed (too much other noise). Sort of like a click/clack every rotation. Noise made by the cam working to open a valve then when the valve is closing the pressure is reversed and forces the gear backwards (backlash). Use the poor mans stethoscope placed on the timing cover and get a mate to wind the motor over (4th gear, plugs removed).
Cheers

[limeyrob]

Since the noise has only appeared since the rocker off job my suspicion is with the rockers.  Check and re-check the clearances. This can be quite a job if there is wear on the adjusters.  If you can feel a step on an adjuster you can unscrew it and emery cloth is a bit to get rid of it.