View Full Version : quick rejetting question

03-12-2015, 11:48 AM
Im buying a completely stock Blast this friday and first thing I want to do is drill out the stock exhaust like I've seen posted elsewhere. Is rejetting required after doing this?

03-13-2015, 03:38 AM
Re-jetting is not required, but it is a good idea if you want to reach the full top-end potential or if you feel that the driveability has degraded.

Here is a thread on BWB with lots of suggestions on Blast jetting with aftermarket exhaust: http://www.badweatherbikers.com/buell/messages/20164/6812.html

Don't forget that you also have a jet needle for tuning of the critical mid-range area, if needed.

Let us know when you make the purchase, and post a few pics when you get the chance!

03-23-2015, 01:06 PM
So the one I ended up buying had a Vance and hines exhaust. Recent carb build and im hoping the guy was smart enough to rejet for the exhaust also. I cleaned and regapped my plug an will be doing a fluid change this weekend.

03-24-2015, 12:24 AM
i plan on getting a new exhaust and maybe one of dans air filter mods. my question is: if i just get the Jardine exhaust what do i need to rejet it to. and would i need to rejet again if i later decide to get the air filter or would i just keep it the same? i have read a bit on this but its a little unclear.

03-24-2015, 12:54 AM
I put a vance and hines and a k&n in the stock air box last year. I ended up doing a rejet and needle shim. It ran so much better after the carb work. I would take the time and do it. I want to say I went with the 180/48 jets in mine.

03-24-2015, 06:23 PM
180/48 is way too large. It's better than the stock 170(165)/42, but 175/45 is as large as you need to go until you start running an open velocity stack with a race-style exhaust...even then 180/48 pilot is a tad rich.

Been there, done that.