exhast

[sking3111]

When i put a 47mm big bore kit on will my old 49cc exhast still fit?

[90GTVert]

It should still work. Just have a look at the header while it's off and make sure there isn't a restrictor in there. It would basically be a washer that reduces flow through the header.

[reveeen]

Yes is the quick and simple answer.

That said, there are "kits", and then there are "kits".

Ideally You would install your new cylinder, and with a degree wheel, check the port timing. Then you would look up your port timing (or adjust your port timing) on/to the chart towards the bottom of this page here:
49ccscoot.proboards.com/index.cgi?board=yamajog&action=display&thread=1712&page=2
Then you would install a pipe (or exhaust) that works just below, or at, the RPM in that chart. (that RPM being the speed at which the cylinder makes it's power).

There is also, the situation you may find yourself in, with one of the larger BBK's where the exhaust port is HUGE (32+mm) and most "normal" pipes are 22-26mm. Many times the stock exhaust will bolt up, but there is really little sense in it.

[1quikvento]

At first I had wondered the same thing. I found my answers about that in the tech section. Just gotta devote some time to reading, cuz theres a lot of useful info there pertaining to almost everytrhing u might wanna do to your scoot..