flat low to mid rpm performance

[jdjcarguy]

i have installed a fmf gnarly pipe, removed the air box lid, k&n air filter, rad reed as suggested on the forum and the bike is very sluggish up to mid rpm after that it rips. I live at 6800' above sea level and would like a little more low end performance any help would be appreciated thx in advance

 

[moridin]

If you are running stock jetting - you are way rich (sultan like) up there in the clouds.

Check the jetting section on the FMF site for your bike and try dropping 1 on both the main and idle. That would be a good place to start. You will probably have to go even more.

sn

 

[Twiztid One]

like mordin said , time to jet it :) your running a little rich , i'd start off going 1 leaner on the main and doing a plug chop and see where your at . read the jetting tips it helps understand whats going on with your carb. , it helped me through it .

 

[moridin]

I came across this really nice matrix that broke jetting apperature size down by altitude. While it isnt 100% accurate - it is probably 99% there.

You basically get your bike baselined at sea level and use the percentile adjustment from there. Ie if 152 main at 700 feet - then at 6000 feet would be 155*.94=145 (or something like that).

I used this several times on previous bikes and it is dead on for trips out west.

I will see if I can find the link.

 

[cicone]

moridin---the matrix is on this site under tech tips/carb tuning---and it IS very accurate per my experience!

 

[John Harris]

At those elevations you will be way down on power and you would probably enjoy a 12 tooth countershaft sproket, but jetting is the key.