Big Bore jetting Q

installed cw BB 12.1cr, fcr mx 39, mrd/ssw.

The question is, should I go up or down on the main jet?


what is the current jetting?

162mj,emn 3rd clip,45pj 2.5af

I had a 158 MJ in and switched to the 162 because it seemed to run out of steam at top end

you swithced form 158 to 162 after you installed the big bore or before?

Before Big Bore 160 then big bore

Then 158 and now 162

you usually end up a size or 2 smaller.

Should I have stayed with the 158 or should I go to a 155

Mine runs best with a 155. Seems we have similar bikes/locations. Mine will run fine from 155 thru 160 but will have a harder pull up top with the 155 and a somewhat crisper throttle in the mids. I also noticed you have a free flowing MRD and I run an expensive titanium stock pipe :ride: so you may benefit from a size up.

You should be right at the sweet spot with a 158..Thats my guess..

Thanks I concur.

I've tried from 158-162 and like the 158's pull.

Where in florida?

Im in Broward county, Ft. Lauderdale area..


158 usually works very well.

Thanks Eddie

Me too.


I was just wondering what the elevation is in florida. Im running about the same set up but its winter here so can not test properly! In Salt Ste. Marie its the same as Detroit 180m above sea level give or take a few.

The bike seems to really enjoy 160 main but its choppy down low as i expected. Once again its winter so i have now clue how she will like a summer day.

QUOTE=artm3;9184830]Thanks Eddie

Me too.


Were neighbors!

Im in Cooper City.

Ill be listening for ya!


PM Me I'll give my number and we can hook up for a local ride.

I'm heading to Vero for a ride this friday and saturday.

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