Easy 600$ Mod to hang with the big dogs


37 replies to this topic
  • Wolfgangs650r

Posted August 09, 2007 - 08:00 AM

#1

Ok here it is, I bought a 2007 YZ 450 and wanted an easy fix to hang with the guys who have sponsors and the money to have 6 bikes, I went to my dealer and talked to the main wrench.

Here is a cheap(er) key to a white knuckle YZF

1. Go get a Pro Circut Ti-4 slip on
2. Get a Sparks racing TPS Bypass (Throttle Position Sensor) for a YFZ 450 quad
3. A Boysen quick shot pump cover
4. The FMF Stage one jet kit, if you live on the East Coast like me, follow the below 3000 ft settings.
5. And throw in a Twin Air Filter


This is a sure way to keep up with those heavy hitters. I noticed a 15 MPH speed increase, way more torque, tons more usable bottom power, and lightning fast throttle response. Snap like a two stroke running lean. Be frigin careful, because this is not a show room floor YZ anymore. TRUST ME!

  • grayracer513

Posted August 09, 2007 - 08:09 AM

#2

What exactly is item 2 supposed to accomplish?

  • KAS

Posted August 09, 2007 - 08:11 AM

#3

Do you happen to work for a magazine?

This is usually their answer for everything--throw a bunch of aftermarket crap at the bike.

BTW my YZ250 loses response when jetting lean.

  • Wolfgangs650r

Posted August 09, 2007 - 08:18 AM

#4

it simply lets the carb run wide open

  • Wolfgangs650r

Posted August 09, 2007 - 08:18 AM

#5

thats becuse most FCR carbs tend to bog with heavy acceleration

  • ZacUSNYR

Posted August 09, 2007 - 08:20 AM

#6

Do you happen to work for a magazine?

This is usually their answer for everything--throw a bunch of aftermarket crap at the bike.

BTW my YZ250 loses response when jetting lean.

Yea because the concept of more air/fuel in and more exhaust out making more power is hard to believe.

heh

  • ZacUSNYR

Posted August 09, 2007 - 08:21 AM

#7

it simply lets the carb run wide open

The TPS may be altering to the ignition timing - by unplugging it you're eliminating that. Block off or unplugging will do the same thing.

  • Wolfgangs650r

Posted August 09, 2007 - 08:26 AM

#8

no, I tried that, all unplugging it will do is bog even more, it feels like its gonna stall out, and it takes forever to start

  • KYMXRacer

Posted August 09, 2007 - 08:41 AM

#9

Here's a suggestion to hang with those "heavy hitters"...


More seat time! :applause:

  • grayracer513

Posted August 09, 2007 - 09:24 AM

#10

it simply lets the carb run wide open

The TPS has no effect whatsoever on the carb's ability to run at full throttle.

The advance curve of the CDI unit is based on two pieces of information: engine RPM and throttle position. TPS signal voltage to the CDI is lowest at full throttle and highest at idle. At full throttle, at any given RPM, the engine needs less advance, so at very low voltages, the throttle position side of the equation is retarded, and then mapped only to engine RPM. At cruising speeds, especially where the rpm is higher, but the throttle farther closed, the engine has reduced dynamic compression because of the high vacuum in the intake tract. This calls for longer ignition advance in order to optimize performance.

The reason that the TPS is set up so that low voltage equates to full throttle has to do with fault tolerance. If the TPS circuit fails in any way, the most likely result is that signal voltage would drop. In that situation, the ingition system needs to revert to a condition that will be safe for the engine under any condition, and that means that the ignition advance is retarded back as if the engine were full throttle at all times, since the opposite response would result in dangerous preignition. So, by bypassing or disconnecting the TPS, all that you've done is to put the ignition system into a permanaent full throttle state, crippling the part throttle advance control, and inhibiting part throttle performance.

Both of my bikes have the TPS connected. Neither one bogs. The fact is that the change in timing that occurs by deleting the TPS simply covers up the real issues, which are 90% jetting and pump timing. Better to spend $100 on the Zip-Tyy modification and keep the TPS, rather than blow $20 on a screw.

Looks like a great product to add to my Black Feather Racing Equipment line. :rolleyes:

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  • Wiz636

Posted August 09, 2007 - 09:43 AM

#11

So...are you hangin' with the big dogs now?

  • moto2000

Posted August 09, 2007 - 10:06 AM

#12

Where did the 15mph speed increase come from? I didn't notice any gearing changes......

  • WB450

Posted August 09, 2007 - 10:32 AM

#13

Always informative.

  • Brokenparts123

Posted August 09, 2007 - 10:34 AM

#14

How does adding more power change your gearing? Please tell me....

All it does is help you reach your top speed quicker, not give you more.

  • Ga426owner

Posted August 09, 2007 - 10:44 AM

#15

Do you happen to work for a magazine?

This is usually their answer for everything--throw a bunch of aftermarket crap at the bike.



I am in big trouble then...........:foul:


back to the point: 15mph faster.......what are we in a supermoto or what.....

I agree the pipe and a carb mod (not a quickshot but a ZipTy Carb mod)would help but not sure about the TPS "thing a ma jiggy":excuseme:

The bigDogs,,,are running special cranks etc.....for max power and maxed out wallets....yikes:p I just want a fast bike that runs good and last....:banghead:

  • matts06yzf

Posted August 09, 2007 - 10:56 AM

#16

Ok here it is, I bought a 2007 YZ 450 and wanted an easy fix to hang with the guys who have sponsors and the money to have 6 bikes, I went to my dealer and talked to the main wrench.

Here is a cheap(er) key to a white knuckle YZF

1. Go get a Pro Circut Ti-4 slip on
2. Get a Sparks racing TPS Bypass (Throttle Position Sensor) for a YFZ 450 quad
3. A Boysen quick shot pump cover
4. The FMF Stage one jet kit, if you live on the East Coast like me, follow the below 3000 ft settings.
5. And throw in a Twin Air Filter


This is a sure way to keep up with those heavy hitters. I noticed a 15 MPH speed increase, way more torque, tons more usable bottom power, and lightning fast throttle response. Snap like a two stroke running lean. Be frigin careful, because this is not a show room floor YZ anymore. TRUST ME!



Interesting, I have a hell of alot more upgrades and better ones on my 450 and ummm not even close to a works bike of any sort. Different league bro. 1st off the fmf kit is trash I had it replaced it, I have quickshot did zero good, Dr D, exhaust showed alot more gains in test than pro circuit, and send your carb to zip ty will work alot better. Every mod here is what damn near all of us have or most have alot more. This normal nothing special but glad it make you excited.:crazy:

  • Justin89

Posted August 09, 2007 - 01:44 PM

#17

Here's a suggestion to hang with those "heavy hitters"...


More seat time! :applause:


I second that...they are a "heavy hitter" for a reason.

  • tnl

Posted August 09, 2007 - 03:38 PM

#18

I second that...they are a "heavy hitter" for a reason.


Ever read the article in Dirt Rider magazine article about the editor I think it's Jimmy something that raced a 16 year old dude on a 450 and got blown away? The 16 year old beat him in step down intervals in bikes like 450 to a 250 to a 100 all the way to a 80 or something similar. Seat time baby! Along with a little help from genes.

  • bigwake

Posted August 09, 2007 - 05:19 PM

#19

..ya..my friend races down here in florida and his mod bike runs on some kinda crazy weerd fuel that smells like nail polish remover..and his bike is runnin 75 hp..and he even gets beat sometimes..by lesser machines..

  • Brokenparts123

Posted August 09, 2007 - 05:23 PM

#20

..ya..my friend races down here in florida and his mod bike runs on some kinda crazy weerd fuel that smells like nail polish remover..and his bike is runnin 75 hp..and he even gets beat sometimes..by lesser machines..




Hmm... something smells bad......... Is that bullshit im smelling?




Yup.





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