My 84 250r is jetted to run with an fmf slip on and a uni filter w/ airbox lid. I'm planning on adding an fmf pipe and taking off the lid. I'm not sure what size jets are in right now because that's how the bike came when I got it. But is it safe to say that I should jump up at least 4 sizes on the main to start? Do I need to change the pilot? Also, what is the advantage of adding a reed spacer? I'm thinking of getting one for my 84 and 87. Thanks for the info.

 

my opinion is to jet up 2-3 sizes on main and warm up motor,take it to full throttle in 3rd gear,hit kill switch,check plug for color(plug chopping) adjust jets as necessary to get tan to medium brown in color.as far as pilot jet is concerned ,i usually go down one size under stock(whateverv that is for yours) my machine is down one on pilot,2 on main from stock with box open also.thats mine though,they are all a little different.better to start rich and work down(obviously).the one smaller pilot seems to keep mine nice and crisp with no loading up.tan plug ,1.5 years on that same plug...works for me! good luck and be patient...its definately worth the time to get it right. i always carry two spare plugs with me and end up loaning them to incorrectly jetted machines![img]i/expressions/face-icon-small-happy.gif[/img]