5 free horsepower

I disconnected the Throttle Position Sensor today on my 04 YZ 450 F and the bike hawls the motor is stone stock except for a Power now and this mod. Thanks T dub

Now do the airbox mod! :)

how many 04 450s do you have?

The air box mod is basically a velocity stack on the back of the carb right?

RHC said that the 04 CRF 450 carb flows better and is good for another 3 hp, then I can use the stock air box.

I have not even changed the pipe yet, these are unbelievable bikes.

I had an 03 now have an 04 I'd like to have a 05 250 f have to talk to the wife about that though.

do you have a link to the Throttle Position Sensor mod you used... free hp is good

Rev,

It's a simple mod.....just unplug the TPS. Cover both connectors and go ride!

Hey Satch0922

Did you do this to your 426? How do you like the performance?

I did it Sunday when I cleaned my carb. First "test" ride is today at Splendora!! I'll let you know how it works.

Cool, are ya racing or just practicing?

Yeah, let me know when you get back too.

I have never heard of this mod. Where is the TPS located? What does it do?

OK. I'm very new to 4-strokes and I often see posts that mention cleaning the carb. I have raced 2-strokes for years and didn't hardley ever clean the carb. Never had a problem either. Is this something unique to thumpers or just that I'm not accustomed to good preventative maintenance? Thanks.

Mike

I have never heard of this mod. Where is the TPS located? What does it do?

Sean, big thread on it, including a dyno chart - here

I have found the cleaner the gas going in is the less problems you will have.

I use auto body paint strainers.

A clean airfilter makes a difference to.

There is a drain and an access port to drain fuel. I wouldn't worry about it to much.

OK. I'm very new to 4-strokes and I often see posts that mention cleaning the carb. I have raced 2-strokes for years and didn't hardley ever clean the carb. Never had a problem either. Is this something unique to thumpers or just that I'm not accustomed to good preventative maintenance? Thanks.

Mike

The 4-strokes just seem to be very finiky and a dirty carb can make it run really really bad. The pilot circuits are small and get clogged easily. Some junk in the pilot jet had my bike cutting out, popping, spitting, was horrible at anything less than about 1/3 throttle. Cleaned the carb and presto good as new.

newbi dumb question, is this mod only for 04s, how about my 03 :)

thanks in advance

ok i've checked the threads and looked at all the links people posted and, still don't see where this cable connection is. one of the threads says not to do it at the carb but hell, i'm not sure which that one is. anyone got a step by step with pictures for those of us that are a not as experienced with mod's.

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