Jetting 2001 Katana 750

[sel02]

2001 Katana 750. The only mod I have on my bike is a D&D slip on exhaust. I may be replacing the stock header with an aftermarket to complete the system soon.

Questions are...What are the stock jet sizes? Could I benefit from a jetting upgrade?

So with a full exhaust system, should jetting be changed and to what sizes?

I know there are many Stage 1 - 3 jet kits out there, but not interested in spending $100 for one. I usually drill my jets if I need to go bigger to compensate for lean conditions and has always worked fine.

[Tmod]

Keep in mind that drilling or changing jets sizes does not correct the entire fuel curve, You are addressing one part of it and that is it. Drilling main jets is marginal at best as you have no way to flow them and see where they are at. Also how do you address the mid-range fuel curve? You are not trying to grind the needle with a bench grinder are you?

Tmod

[blitz2190]

If you get a complete drill set like a machinist set you can drill the jets pretty acuratly as long as its square and on a press also you can shim the needle but like tmod pointed out you need a better needle with a different angle cut, but shimming can get you close, of couse just buying the kit and doing it correctly is much easier, when im on my computer ill post the drill to jet size cross over