Anyone ever tried jetting calculator or similar? Seems pretty handy! As I don't know where to start with jetting my PWK for my 250 ATK, I may go utilize it, unless anyone here might have some jetting advice?
I have not ever used a jetting calculator, but it does seem like it could be very handy. There are quite a lot of variables though, with porting being the one that is going to be the biggest and most unpredictable variable to calculate based on.
Are there any forums or groups for this engine model / bike? Surely someone has put a PWK on this model previously.
Re: Jetting Calculator Program/Spreadsheet
Posted: 12:01 pm May 11 2026
by brademan76
Chuck78 wrote: 09:21 am May 11 2026
I have not ever used a jetting calculator, but it does seem like it could be very handy. There are quite a lot of variables though, with porting being the one that is going to be the biggest and most unpredictable variable to calculate based on.
Are there any forums or groups for this engine model / bike? Surely someone has put a PWK on this model previously.
I have found very little discussion of the bike online. There is a Facebook group for ATK bikes but the other models are far and away more owned and discussed. I'll figure it out.
Re: Jetting Calculator Program/Spreadsheet
Posted: 08:27 pm May 11 2026
by kdxdazz
Spend the money on a wideband O2 sensor, I live near the equator and I had no idea where to start with jetting all of my bikes as most of the jetting advice comes from the US and that doesn't work at all where I live
Re: Jetting Calculator Program/Spreadsheet
Posted: 10:59 am May 12 2026
by brademan76
kdxdazz wrote: 08:27 pm May 11 2026
Spend the money on a wideband O2 sensor, I live near the equator and I had no idea where to start with jetting all of my bikes as most of the jetting advice comes from the US and that doesn't work at all where I live
i will have to look into this option! thanks for the advice!
kdxdazz wrote: 08:27 pm May 11 2026
Spend the money on a wideband O2 sensor, I live near the equator and I had no idea where to start with jetting all of my bikes as most of the jetting advice comes from the US and that doesn't work at all where I live
i will have to look into this option! thanks for the advice!
I've found that the weld-in wideband o2 sensor bung being welded into the pipe works significantly better than the clamp-on venturi effect tailpipe sensor mounting for the o2 sensor bung, just FYI...
kdxdazz wrote: 08:27 pm May 11 2026
Spend the money on a wideband O2 sensor, I live near the equator and I had no idea where to start with jetting all of my bikes as most of the jetting advice comes from the US and that doesn't work at all where I live
i will have to look into this option! thanks for the advice!
I've found that the weld-in wideband o2 sensor bung being welded into the pipe works significantly better than the clamp-on venturi effect tailpipe sensor mounting for the o2 sensor bung, just FYI...
Ive only ever used the weld in bung, didn't know there was a clamp on option, sensor near the tail pipe in a 2 stroke wouldn't work for long and get quickly covered in oil.
So you went the O2 sensor route, that's great, how are you enjoying it? Feels like a revelation when it comes to jetting right ?
Re: Jetting Calculator Program/Spreadsheet
Posted: 05:49 pm May 12 2026
by Chuck78
I have only used it on my 4-cylinder 4-stroke vintage air cooled high performance street bikes, but yes, it is wonderful for getting you out of the dark and to a close point when tuning modified bikes.