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Post by sime66 on Aug 12, 2013 7:33:28 GMT
Apologies in advance if this is a foolish question.
When I’ve got my clutch out, instead of stripping and rebuilding it, is this possibly a good time to upgrade it instead? Or is my DR177 not up to the job? (We know it’s a poof). Being 1983, I’ve got a PX-E, but not an EFL (Arcobaleno). To be honest I’m only just reading up about clutches and teeth and plates, initially to work out what I need to hand before I do the job, but I keep seeing complete PX200/Cosa 23tooth, 4 plates, 7 spring, and I was just wondering if I could swap. Haynes just tells my I have 3 plates, but I’m not sure how many teeth; they all seem pretty interchangeable, but I have no understanding of the implications, except that common sense tells me what better plates, springs and teeth will do. SIP is good for what's available, but not for sussing out what I have. I still have the bigger carb ready to fit, if that makes any difference.
Better clutch and bigger carb?….
I’ll buy a good’un if it’s a sensible upgrade, and I’ll still strip the old one to learn how to do it.
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Post by sbwnik on Aug 12, 2013 8:30:15 GMT
If the engine is ported, then an early Cosa clutch (thats a mk1 clutch but one tooth fewer than a p200) with a complete P200 gearbox may be worth trying. I know a Polini 166 will pull one. A T5 top gear would be a must though.
If not ported then leave alone.
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Post by sime66 on Aug 12, 2013 9:41:00 GMT
Righto, thanks. I'll keep it simple this time round. I see a 22t, 4 plate Cosa clutch in SIP, which looks like the one you mean, and it says I need a P200 clutch cover. Doesn't account for engine grunt though. Catalogues don't give dirty, hands-on experience. In any case, interesting subject, but more involved than I realised, so I've got information overload this morning, and I don't want to tackle the gearbox now, so I'll just get back on the road with an overhaul.
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Post by sbwnik on Aug 12, 2013 14:31:36 GMT
The problem when you say 'Cosa clutch' is that it isn't actually a specific clutch for a Cosa. It's complicated...
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Post by sime66 on Aug 12, 2013 15:35:47 GMT
I didn’t realise just how complicated! But I’m glad I had a look at it. It is definitely something I’ll learn-up, and pick brains over. It's a job for the future though. What I get is that better springs and more plates give greater friction, number of teeth adjusts gearing, and upgrades might end up with baskets needing reinforcing too. Some will physically fit, but not necessarily be suitable for lower power or untuned engines, some require changes to the gearbox, some require changes to the housing, some are no good without changes to the porting as well. In short, there is room for a decent upgrade if you know what you’re doing, your engine is up to it, and you want to play with your porting and your gearbox – not currently in my experience to select what’s correct, and possibly not much use with my engine anyway. That’s OK; I’m happy to strip what I have now and learn, and pick up what I can on the subject as I go along. The next bit may be wrong, but my cylinder has two extra exhaust ports, and the piston is also ported, if that’s what you meant? Those are just the DR standard ones - nothing extra done to it. But I know that is also another can of worms that I know little about, and it doesn't matter now anyway. I was using the SIP catalogue because it is good for finding stuff and looking up compatibility, but I know it isn’t as good as experience of what fits and works. Looking at loads of Cosa Standard, 1, 2, T5, PX & 20,21,22&23 tooth clutches, the one upgrade (22t, 4plate) that fitted my engine and best tallied with what you described, just before my brain exploded, was this: I've dropped the idea for now anyway, and this was unbranded as far as I can tell, and seems to be and obsolete model with SIP now anyway.
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Post by sbwnik on Aug 12, 2013 19:22:24 GMT
Porting involves opening cylinder and engine ports up so that they match perfectly - don't forget to match to the gasket too - which increases gas flow. There are two different types of clutch. The early type (which you probably have) and the so-called Cosa clutch. I say 'so-called' as early Cosas had the older style clutch, and they were also fitted to the other scooters being made by Piaggio at the time. The clutch in a Cosa 200 is one tooth less than the P200 giving slightly lower gearing. As for the clutch cover, if you pop it off, you'll see that there are two small webs across it. They need grinding down with a dremmel type tool. The difference between the two types of clutch is that the early ones have larger surface area than the 'Cosa' type (illustrated in your picture BTW) meaning they're able to handle power better, and the stronger springs help the plates hold together better. Straight forward really.....
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