SusKatCas
Forum Apprentice
So, I bought a non-running GS500E. (Yeah I know...) It was last inspected in NY in 2013.
Going through brakes, carbs and valves before I crank it.
Everything is going pretty well except for valves. Specifically the left hand exhaust valve in fact.
As dragged home, I could not measure clearance on either exhaust valve. My process in that case has been to swap in a thin (2.30mm) shim from a different bike, with a 25mm OD. Z1 shims arrived today and with a swap from inlet right to inlet left and two new shims the inlet valves and right hand exhaust valve are now measure 0.07 or 0.08mm gap.
The left hand exhaust valve still measure no gap.
- old shim was 2.65mm
- swapped in the 2.30mm and measure 0.25mm gap
- calculated that I needed a 2.50mm shim
- as noted above installing that shim still shows zero gap
My theory is that this bucket must not be perfectly flat? Using the 25mm test shim worked okay for the GS650 I dragged home a couple years back and for the right hand exhaust valve on this bike.
I have carefully inspected with a flashlight and swabbed the bucket with a q-tip with no sign of any debris.
I could order the next two size's of shim I suppose? Or I could order a thin one of the proper OD?
That said, am I kidding myself that there is any chance I don't need to lift the head off? It appears the bike did run with the original minimum of 0.15mm interference on this valve.
The bike has 18,600 miles on it. I had hoped to get the ole girl running before the snow flies, I guess that is the only reason I am not ordering 2.30mm thick 29.5mm OD shim right now.
Ok, fire away boys...
Thanks, Alan
Going through brakes, carbs and valves before I crank it.
Everything is going pretty well except for valves. Specifically the left hand exhaust valve in fact.
As dragged home, I could not measure clearance on either exhaust valve. My process in that case has been to swap in a thin (2.30mm) shim from a different bike, with a 25mm OD. Z1 shims arrived today and with a swap from inlet right to inlet left and two new shims the inlet valves and right hand exhaust valve are now measure 0.07 or 0.08mm gap.
The left hand exhaust valve still measure no gap.
- old shim was 2.65mm
- swapped in the 2.30mm and measure 0.25mm gap
- calculated that I needed a 2.50mm shim
- as noted above installing that shim still shows zero gap
My theory is that this bucket must not be perfectly flat? Using the 25mm test shim worked okay for the GS650 I dragged home a couple years back and for the right hand exhaust valve on this bike.
I have carefully inspected with a flashlight and swabbed the bucket with a q-tip with no sign of any debris.
I could order the next two size's of shim I suppose? Or I could order a thin one of the proper OD?
That said, am I kidding myself that there is any chance I don't need to lift the head off? It appears the bike did run with the original minimum of 0.15mm interference on this valve.
The bike has 18,600 miles on it. I had hoped to get the ole girl running before the snow flies, I guess that is the only reason I am not ordering 2.30mm thick 29.5mm OD shim right now.
Ok, fire away boys...
Thanks, Alan
