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Post by partanen on Jun 15, 2014 15:06:23 GMT
When you measured stock head, was it older or newer model? I thought you wrote about older model. Older PX 200 had higher compression ratio, maybe 9.8:1 ?
I haven't found older model head so I bought MMW. I'm gonna buy older head if I can find one.
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Post by partanen on Jun 15, 2014 16:15:37 GMT
I forgot to mention that ignition timing is at 20 degrees now. Getting better.
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Post by vespasco on Jun 16, 2014 11:54:06 GMT
The stock head i compared to was the later style with the spacer / 'lugs', marked '992355 3' Cumbustion chamber volume = 12.5 Squish band = 14.5cc (With a squish band width of 14mm) The 0.0mm squish MMW head CCV = 18cc SB = 10cc I made a note when toying with this head (mmw) that it would be more suited to a stock motor! But never had a chance to experiment. Only to see if the lower squish height would make much difference to reliability/fuel economy/detonation issues. Speed or power / performance would be virtually unchanged. i've been trying to find our for a long time exactly what cc's the older head has but no one anywhere seems to have actually measured one and i dont have one to measure. Maybe if i ask Nik again he could measure one of his old type heads, or take a photo?! Eh Nik ?? or someone who has an old style head!! Im still wondering how much (if any) difference there is between old and new heads) Just because piaggio states different compression ratios does not necessarily mean that its only the heads that changed design/volume. But i have just found another detail in my notes with an unknown (old or new???) stock p/x200 head and that measured; CCV = 14cc SB = 13cc (With a squish band width of 12mm) But even with this head it still makes it a total of 27cc (All measurements +/- 0.5cc, with an old spark plug in the hole, using a large syringe from the chemists and 2 stroke oil).
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Post by partanen on Jun 16, 2014 16:28:39 GMT
This is getting even more interesting. I only wish I was measured both heads, but I didn't have proper equipments that time. Anyway MMW sits closer to cylinder. At least I can always go back to original as I have untouched original head at my garage. That's why I do not regret that I bought MMW head. Until I see holed piston.
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Post by vespasco on Jun 16, 2014 22:13:45 GMT
Kool. I think the head will work fine, with little fine adjustments to timing, mix screw and maybe jetting. If you find you have any kind of detonation issues try upgrading to a premium petrol. Keep us posted. Id like to know how it goes.
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