I unplugged my throttle position sensor!!

I finally got around to unplugging my TPS on my 03' 450. Man, I should have done this a long time ago! I actually feel like I can hold onto the thing now. I didn't realize how much the "hit" of the bike drained my strength. I immediately found myself riding longer before tiring out.

I played around with it for a while. I rode a lap with it plugged in and then with it unplugged. I did that several times, then went to the truck and taped it up for good. I can't say I really felt a power increase, but I've probably never felt how much power this bike really makes with it plugged in. But I definitely noticed that the bike pulled smoother and more consistant. Felt like I had much better throttle control.

ANyone who hasn't done it needs to give it a try at least. My guess is if you do, it will stay unplugged.


That's the plug on the carb ( shifter side)right? I broke mine off the other day. I duct taped it back in though. I'm really not sure if it is working or not. A new one list for $160, but if it runs better unhooked, I'll say the hell with it.

i tried it as well and didnt feel much of a diff. what i did feel is the bike being very smooth and not just giving you that "hit". as far as power i didnt really feel more power. im gonna take it to the track soon and see if feels more different.

ditto ...

Where are you unplugging the sensor at? On the carb or on the frame under the seat?


do you guys think that unhooking TPS is just taking away a little bit of HP where the "hit" is? i tried it unplugged and plugged in on the tar road and it just seemed to feel like it didn't hav as much power when unplugged. it probably just seems that way i guess cos theres more power before the hit when unplugged. it does feel easier to ride on the track though.

do you guys think that unhooking TPS is just taking away a little bit of HP where the "hit" is?

There's no need to think anything, since the dyno graphs have been posted. Your alternative speculation is correct, removing the TPS does indeed fill a dip in the torque curve, removing the sensation of a hit as the power comes back on.

looks like I also will be trying it...

fellow YZ guy


It definitly smooths it out but I thought it made the bike feel slow. I went back to it.

I "tested' unhooking mine on my 426. My recommendation , on the 426, leave it hooked up. It fouled up the way the bike ran on pump gas...and I don't need or want race gas!

you guys with 450's have different results though.

I think the big "HIT" is one of the best parts of the bike Ill leave mine stock.

fouled up the way the bike ran on pump gas..."

i think your right, i noticed more bogging. maybe the tps help fix minor jetting problems. but perhaps you could tune the jetting perfectly and have the tps disconnected :thumbsup:

i noticed that when i unhooked mine, it made my bike backfire or pop on decelleration. this usaully indicates that the bike is running lean. so i think it made my bike run lean. anyone else experience this?

Sorry guys...I'm not with you on unplugging anything. Why get rid of "the hit"...isn't that what you need to clear a double out of a tight corner, or around the first turn? Instead of slowing the bike down, work on riding faster. The only change I'd make, or have made is a 47 tooth rear. If everybody hates "the hit" buy a CRF.

Sorry to go the other, but I like the gnarly pull.


I like the hit, before a jump. Do you trail ride or what? :thumbsup:

Guys, I tested several '03 450s, and they all showed the same results. As I don't ride much anymore, I can only depend on the input from other riders which for the most part saw a benefit in disconnecting. I have not tested the '04 or the 426, so I can only report my findings on the '03.


"get rid of the hit... Instead of slowing the bike down, work on riding faster."

the hit is the part after the dip. disconnecting the TPS does add power where that dip is, but the bogging and popping that come with it dont outwiegh the advantages. i reconnected mine and now the bike runs right. :thumbsup:

i do trail ride. we are not all trying to make the bike, or even ourselves, faster. i like being able to hold onto my machine. :awww:

The TPS has nothing to do with the jetting, just the timing. If you are popping on decel, it isn't because you unplugged the TPS. There have been MANY satisfied riders who have unplugged vs. a very few that have stated otherwise.

As you can see, the graph shows a "slight" advantage at lower rpm with it plugged in. My observation and the reason I posted my results was to address the complaining about the "hit".

You will not melt down your motor if you unplug. If you are getting spark knock, you are using questionable fuel. If you feel you are going slower, it prob only feels that way. if you think the "hit" gets you over the jump, you are mistaken. JMOs

If you are getting spark knock, you are using questionable fuel.

Aren't we all! :thumbsup:

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now