Hi Marco,
I see you dont like your old, dirty Ignition coil.
You want your NEW one, is OK - you payed for it, invested money, and I agree tolerances are HUGE, but Bosch want to protect itself from complaints and returns - they produce parts sometimes OK sometimes out of CHINESIUM, low quality copper wire even aluminum is used to save on production costs, but MBA will earn their boneses that is only important
I graduated eletrotechnics college, even many technical people dont understand magnetism and induction AT ALL.
What if I offer you Speaker and say is OK tolerance is from 6 to 10 Ohm and you can play music on it.
On my college it was the most difficult exam where many were failing for months unable to EVEN pass with lowest grade - it was Electromagnetism and I got A++
LISTEN - Lets make a deal: I helped you here a lot, I think fair deal is to give it to me as present. Your old coil. I like collecting ECE parts , even dirty ones
And you take your new from Bosch. It cant be that bad, also you will be able to learn from experience how engine behaves when spark has lower energy, what happens with acceleration and consumption...
OK?
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PS DONT SAND DISTRIBUTOR CAP, I only wrote do polish end of distributor arm nothing else
And what you planned to do with holes in Carbon in cap? Polish them out? Make gap even larger? Is OK from pictures - even new will be like that in few months...
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About compression, it is important that values are similar and yours are OK, not 14 anymore but who knows with what values that engine left the factory, how was worker on assembly line happy or not during shift, got something from his wife (or boyfriend) that night or not
About shims, not only Kawasaki, they are also used on some Peugeots cars and again after setting it correctly car won´t be faster
Again, you can use what you have maybe just change places? You need to measure and they are probably 80% OK, maybe 100% all still OK, maybe only need to buy one or two or none at 80.000kms
When they did NARDO speed test, they checked valve gaps, they stayed in tolerance during GREAT ABUSE 50.000km at max revs and 255kmh
Don´t worry it is old Merc Quality not BMW or Gruppo Fiat
And REMEMBER they have quite tolerance, measure them COLD and MAKE SURE exhaust are OK FIRST = BETTER LARGER TOLERANCE THAN EXACT OR TOO SMALL
Intake will never burn valves, they are not thermally stressed so here any tolerance is OK but of course smallest tolerance will give slightly better breathing of engine.
they are adjusted ONLY not to get too long, because if that happens valve/seat will burn because it will not close (and cool off) properly
BECAUSE every opening of valve is like little hammer punch. It gets by 0.00001% longer and it accumulates. Also valve seat shrinks by 0.000001% and therefore valve adjustement is made to have correct gap. Gap to camshaft is important for noise levels, not burn valves and has slight influence on power (but minimal)
Meaning when they heat up and become even longer important is that they are still able to close valve to valve seat, therefore not lose compression and be able to cool off through touching seat and further into cylinder head.
Also is important for head rebuilds to ALWAYS renew exhaust valve guides, they get worn much faster than intake guides due to thermal stress.
Because they are big COOLING AID for cooling valves - only cooling through valve seat is not enough!
Bye,
Nikola.