- Joined
- Jan 28, 2015
- Messages
- 277
- Location
- Winnipeg, Canada
Hi bergers so I just got a berg fe650 and I want to check the valves as the last owner did little or no maintainence.
I removed all the items and valve covers and rotated the engine to tdc with a straw so the piston is at the top and it at the rocking point also there was a sharpie line on the rotor which matched.
So the question is when I crack open the nut I expected some slack on the screw buts it's tight and would need at least one turn out to get clearance.
The bike starts and runs so it may be close. My question is am I safe opening all the screws and tight down to the touch and then use the one hex unscrew per the thread.
Yes, you are safe to do this. The only way you could mess it up would be if you unscrewed the nut or bolt all the way and it fell off (and even then you could retrieve with a magnet easily enough).
The 1/6th turn method (don't know who decided to suggest 1/8th turn) is the way to go for me on my 650. I haven't checked if the valve shaft tops and domed (or if the tappet are cupped), but there is no way for me to get a feeler gauge in there. Maybe if you buy one of those special KTM ones (or make your own), then the feeler gauge would work. But if your tappets are cupped or valves domed, the feeler gauge method isn't accurate.
You may already know this, but clearance is 0.12mm ~= 0.005"
Screw pitch on tappet = 0.75 (mm)
1/6 x 0.75mm ~= 0.12 mm
1/8 x 0.75mm ~= 0.09 mm (too tight and therefore wrong as per manual)