I have 450 yfz 2005 with less then 1 hour on it. After riding it for the first time I was so disappointed on it's low end and overall performance. After asking around I heard that exhaust and rejetting makes a world of difference.

So this is what I did.

BUB Moto C4 Carbon Fiber/Titanium System

K&N Proflow w/o lid

175 Main jet

NCVQ on 7th position

Stock pilot 4 turns

About 825ft above sea level

It still lack in the low end and runs a little rough. Any suggestions?

Also while doing all this I unhook my tps (throttle position sensor), and now I'm not sure if I hook it up right? HELP ME PLEASE!!!

i think you have jetting set to high position set high also

Sounds like your main is about right for that altitude, I am at 7K Ft and run a 155 main. I had the NCVQ needle but it doesn't seem to work as well up here. With the needle at 4 turns out your pilot is lean, to make adjustments easier get an aftermarket TY needle then up your pilot one to two sizes. I went with a Dr D exhaust and -6 TT flywheel I run mainly in the woods and trails of Co. I have never had a problem stalling it they tons of bottom end torque when jetted correctly. Also do the CAM mod that will increase the power all around

Where did you unhook the TPS? At the thumb throttle or carb? The system takes these (2) points as inputs.

at the carb

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