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Installed a Fatty, jetting changes?

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All, I just swapped my dented up stock pipe for a new FMF Fatty.  I like to think I had it jetted pretty darn well with the stock pipe.  What jetting changes should I expect to make by adding the Fatty?  FMF doesn't list jetting specs for the yz's for some reason, and they haven't returned my email yet.

I know I've got to spend some time and try things, but where should I expect to start?

 

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I swap between fatty and stock with no changes at all.  I'm sure someone will say I'm wrong.....  I probably am...

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I swap between fatty and stock with no changes at all.  I'm sure someone will say I'm wrong.....  I probably am...

Same here. I swap between a tatty stock pipe that I use when I ride terrain when I may bash a pipe badly and a shiny fatty when there is less risk of pipe damage.

I run boyesen reeds and jetted to thier specs and it's pretty good so I don't mess with it when I swap between pipes.

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Ya pipes don't really effect jetting to much it should be the same pretty much.  Reed cages and porting more so I'm my experience's anyway. I remember when vforce came out I had new kx125 put one on and it wouldn't even rev up lol was like :facepalm: had to go 4-5 numbers higher in pilot jet . 

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8 hours ago, Motox367 said:

Ya pipes don't really effect jetting to much it should be the same pretty much.

That depends on the pipe, the SST i.e is quite finiqui about jetting.  

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