Okay, well...
The Boss is fine. For some reason Matt hates it after his maths project went wrong. It's a fine pipe, it'll hit around 8k and pull to the rev ceiling of your cylinder. It's got a big header, which lets it rev and rev; but, you'll lose some power compared to, say, a Simonini, simply because the Boss is a fairly cheap pipe. You've probably noticed it's only got two cones (limiting the ability to accurately define a powerband); and the header doesn't have much of a taper, as well as having a small chamber diameter with no dwell section, which reduces the amount of scavenge you'll get from the pipe. That's fine, because the transfers on that cylinder are a little small.
As Kenden would tell ya, the best pipe for that cylinder is the Simonini. He had that, along with a 19?mm PHBG, Malossi reeds, and hit 58. I'd guess you'd hit at least 50 comfortably with a Boss. Don't get any circuit pipe, or Estoril, unless you're okay with your cylinder running out of steam at 45. I mean, yeah, it'll hit 50-something eventually with those pipes, it's just not quite the ride that a higher RPM pipe would give you. You WILL need to get a good clutch, no matter what pipe. Also, buy a CDI as soon as you can afford it. Matt hates those too, he'll tell ya all about it, but the Cold Trailers have had nothing but success with the Hero CDI. I'm sure you're close to somebody with a timing light that'd love to help you with it.
PHBGs are FANTASTIC carburetors. They're a little sensitive, but they will get you going fast. There's a reason all those 2t Scooter teams love Dellorto. For example, Sue in Louisville went 70 on her MK80 with a 21mm PHBG, while there are a LOT of people with 24mm Mikunis on the same cylinder that aren't going as fast. The PHBG knockoffs are, well, knockoffs. They perform fine, mine just started falling apart after about a year. I only paid $30 for it though, so I didn't care. It still worked fine. Check your atomizer, mine had the 4t version, but it never really bothered me much until I got REALLY anal about tuning. BUT, if you're leaving the knockoff atomizer in it, DON'T change the needle. Tuning problems abound if you do that, at least that's what happened to me. You SHOULD get a set (for your cylinder) of genuine Dellorto main and idle jets. I'd say buy a range from 85-100 for your main, and 35-45 for your idle, for that cylinder. That way you'll have some extras, just in case you change your setup in a couple months.
If you need help tuning, Kenden is probably the best person to ask about that setup, or feel free to shoot me an email, or just figure it all out yourself. I'm sure we'd all love to see you up and running.
