I bought an FCR 39 Carb and the guy sent a 52 pilot jet with the carb? I am using a 42 in my stock carb... what is the advantage, if any, to using this big of a pilot jet? And should I stay with my same size MJ that I have now in my stock carb (175)? Any opinions appreciated!

 

You will need different jets, in the new carb. I have a 55 pilot in my fcr. I had a 48 or 50 in the stocker. I think I have a 178 for a main???

 

i always ran around a keihin 170 in my fcr. the pilot jets are totally different styles. we found a 52 to work pretty good year round in the fcr. however temp, elevation, and mods will make a difference

 

I will put in the 52 and mess around with the MJ. Thanks for the help