Recently we have polished the valves. There’s actually little to say about.
I add a few nice pictures because they shine so beautiful 
Polished valves
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Tool to test valve leak tightness
Unfortunately the tilting test with gasoline in the channel only works when the cylinder head is off. So to ensure valve leak tightness I’ve tinkered a little testing tool.
First, go to your DIY store and get a 3/8-inch valve and a 3/8-inch compressed air connection (If you want it really nice also buy a brass shaft for turning).
Then start your turning lathe: On the front you need a spark plug thread M10x1, a hollow-bored shank, and on the back a 3.8-inch thread.
Functionality:
- Shut the valve
- screw into the spark plug hole (works with almost every cylinder head)
- Connect compressed air
- open the lever
- If it whistles at the inlet, a valve seating is broken
- If it whistles at the outlet – same problem
- If the water hoses get hard, the cylinder head gasket is gone
Gearbox weight reduction
Before we reassembled the gearbox we noticed a bit of excess weight on certain gear parts, so we decided to do some gearbox weight reduction.
First of all, the shift drum- a damn heavy part. Unpack the carbide drill (concrete or brick drill) and prepare for about 2 hours of drilling and DON’T drill into the guidance.
If you can do without the neutral indicator – get rid of it. Material can then be taken down from the crankshaft to the bearing surface.
Overall weight savings:
- Original weight: 511g
- Processed: 441g (-70g)
The neutral indicator is gone now, so we can also get rid of the ugly plastic cover along with the heavy bolts:
Original: 28g
Superlight: 8g (-20g)
In the gearbox we have 8 gear-wheels on 2 gear shafts. Wee can drill a few holes with carbide drills into 4 of them.
I didn’t document each of the weights. But on average we took off around 10 – 20g each.
- Overall savings: -74g
Overall gearbox weight reduction:
- shift drum: 70g
- neutral indicator: 20g
- gear-wheels: 74g
- Total: 164g
Maybe, this is not worth the hassle, but i think some of the gear parts are much larger dimensioned in a large-volume V2 engine where we have the possibility to save much more weight.
Polishing the pistons
Last weekend, Daniel helped me polishing the pistons. This reduces heat absorption and the tendency to engine knocking. The edges of the valve seat pockets were also rounded somewhat.
Aluminium engine spacers
Aluminium engine spacers are a simple solution to reduce weight caused by unnecessary steel.
In older motorcycles almost all engine spacers are made of steel. Instead they can be made of aluminum to save up to 2/3 of weight.
The heavy (but mainly ugly) engine spacers of the FZR had to disappear.
The aluminium engine spacers in comparison:
- Engine spacers original: 137g
- Aluminum engine spacers: 50g
- Savings of enormous: 87g
