cr lover

Member
Aug 6, 2001
78
0
i have a 96 cr 250.i have just bought a pro circuit pipe from motosport outlet because i wasnt happy with my fmf gnarly pipe.i saw a shootout article in a 96 motocross action mag,and it bragged about the great mid and top end power on my bike.but with the gnarly all i had was mid and nothing at all on top.it just seemed to take away power in the area that the motor was bilt for. ( i do realize that the fmf is for low and mid). but without wasting any more of your time,what would be some baseline jetting for my bike.or does pc have a website with some jetting specs.
i have a boyesen rad valve , i live at sea level, jetting for a 75 degree day.
now i am running a 175 main,52pilot stock needle.
i was thinking of running a 172 main. i am running amsoil 100 to 1 at 50 to 1 with 92 octain gas.
any help would be great.
 
Last edited:

ProCircuit

Member
Jan 16, 2003
96
0
Pro Circuit recommends the following for your 96 CR250:

172 Main
52 Pilot (Stock)
1369 Needle (Stock)
2nd Position
1 1/2 out on the air screw

Also, all of our specs are with VP C12 race gas at 32:1 with Maxima 927 pre-mix. If you have any further questions please let me know. Good luck.
 

cr lover

Member
Aug 6, 2001
78
0
the problem i am having is that i have three kids,and c 12 if i am not mistaken is $6.oo a gallon.i can handle running maxima 927 at 32:1. but what would happen if i ran the maxima with 92 octain and put in a 172.
other than run at a warmer temp.
i am sorry to bother you,but im am looking for a way to save a little money. but if their is no other options i will do what you say.
thanx again. dave
 

cr25096er

Member
Apr 16, 2002
707
0
wow I was leaner than that for my summer jetting(same bike and pipe) in nj at sea level. i had a 170mj i think a 52 pilot and im not sure of the needle but i never messed w/ it. that was at 32:1 with honda hp2 and 93octain gas. the thing that got me was how little top end power i had during the summer opposed to the winter( same jetting and ratio but a 175mj) Ive been told the 172 would be a waste n make no difference from the 170 but is that true? since my last ride i added a 14 tooth cs sprocket(the rear is 53tooth), and boyesen pro series reeds. how big of a difference should i expect when i get the jetting spot on?
 

ProCircuit

Member
Jan 16, 2003
96
0
We found this jetting to work great, but we also use race gas and don't recommend the Boyesen reeds. Pump gas and reeds can effect the jetting a lot. You are on your own for this one.
 

ProCircuit

Member
Jan 16, 2003
96
0
We have had some problems with the jetting with the Boyesen reed cages. We found the reed cage to hinder performance and cause more problems than it is worth. I would recommend the V-Force reed cage over the Boyesen.
 
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