2013 YZ250 Project Bike Help !

So i just purchased a 2013 YZ250 and its going to be my new project bike.


first mods are all new white ufo restyle kit

white gas tank

full custom 180 decals

full bud hgs racing exhaust

steahly fly wheel weight 


ive always run stock jetting and exhaust so i was wondering what ill have to change when getting the new pipe and what pre mix i should run, my old race bike, sx125 i ran 40:1. the guy i got this bike off ran 50:1 yamalube but he only trail rode and im more of a pinned around the whole track. This is going to be my baby so i want to do everything right, thanks


btw thats my base design but im getting custom 180 decals cause they are my sponsor and do better work


Your riding temp/altitude will influence jetting requirements far more than some exhaust pipe change.

run shell V power 91 fuel, its ethanol free and helps keep detonation under control. with an aftermarket pipe if you are a wide open guy (most think they are but arent lol) go up one on the main jett. I run a fmf gnarly (came with the bike) I have the timing retarded 1degree from stock. and stock jetting. Runs very well, it was advanced 2 degrees from the factory.



if you want to do it right, read the FAQ at the top of the forum. the timing thread, and the squish thread are the two most important things about the yz250. jetting is a bandaid fix for the motor problems on that bike.

Damn that thing is ugly

Damn that thing is ugly

lol I thought it was a KX at a glance, Hey Kyle328 the 2013 YZ250 was finely jetted out of the Crate for its box-stock configuration, if you port it, raise the compression, add an aftermarket exhaust or try to skimp on fuel quality it will ping. Play it safe and go a tad rich, just the addition of the Flywheel weight (which is Awesome! I Have a 8.06 oz GYTR on my 2015) you Really don't need to worry about Re-jetting for, Good luck its an Awesome Machine. :) Edited by HurricaneH

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