CRF450X

The pink wire mod is one of those highly debatable mods for the CRF450X. Seems everyone has an opinion as to whether it does anything or not. Only one result has been verified by everyone and that is that the mod raises the RPM limit by 500 revolutions per minute. But does it do anything else?
Ok guys, so here it is. After looking at the schematic located here and reading through the technical documents on the Honda CRF450x we’ve personally determined in our minds that the CRF450X Igntion Control Module retards timing in certain situations.

The throttle position sensor is connected directly to the ignition control module. Honda states the following in the CRF450X sales literature…

“Carburetor features a throttle position sensor (TPS) that helps maintain linear throttle response throughout the rpm range.”

The TPS is an electrical device, there is no air or fuel connection electrically on the 450X. Therefore the only method to provide a linear throttle response would be to manage the spark circuit via Ignition Control Module based upon RPM which is determined from the Ignition Pulse Generator and compared against the TPS to determine what changes to make. What the pink wire does is take one leg of the circuit off of the TPS and effectively eliminates or reduces the dynamic spark management. Removing this wire more than likely causes the control module to default to a default spark curve/map that was optimized for power from the factory.

Therefore the pink wire mod is a valid power adder depending upon your riding style and how you use your throttle grip actuator. If your easy and roll in and out of your throttle you probably won’t notice any difference. However if your a throttle jockey like I’ve been accused of, you’ll probably notice the engine responding a little snappier due to the lack of spark management.

So what are we going to try next???

-Remove the pink wire and see how it effects the bike in back to back test on the track.

-Remove the TPS from the CRF450X circuit completely and again test the bike in back to back tests on the track.

-Find a CRF450R wiring diagram and see if it’s possible to wire in a an aftermarket hot ignition module such as a Tokyo Mods module and if it makes a noticeable difference.

Stay tuned for more tiral and error with this mysterious mod.

Related posts:

1. Honda Bulletin for 2005 CRF450X Closed Course Competion Modifications…
2. Pro Circuit Thermostrips
3. 2007 Honda CRF450X- Specifications
4. 2006 Honda CRF450X- Specifications

Filed under: Electrical,Engine
4 Comments

4 Responses to “Finally some real logic on what the pink wire mod for the CRF450X does.”

1. CRF450X Says:
   February 14th, 2007 at 3:24 am

   [...] Swap the positions of the Pink wire and the rubber cap. Reconnect the coupler to the wiring harness. (In modified form, the Pink wire is NOT connected to any other wire.) For more pink wire information click here. 10. Remove the noise and emission compliant label from the rear fender. [...]

2. Juice Says:
   April 11th, 2007 at 4:59 pm

   I have 2006 CRF450X and I cut the pink wire. then went for a ride and notice a big diffence in the throttle response,before when i gas it it choked up a little bit,now it perfect.

3. stinky Says:
   November 21st, 2009 at 8:52 am

   hi all i have a 450x 2006 done the air box , jetup , power pipe fmf .wot a diff that made i mean not the same bike any more so now i read up on this pink wire can any body can give me more info on this and where it is thanks if you can stinky

4. scotsman in Qatar ( lexi ) Says:
   May 27th, 2010 at 3:23 am

   ive switched the pink wire and ive noticed a diferance, i also fitted a FMF Mega bomb and a fmf tail pipe fitted the Anthena 490 kit, fitted a scary go fast air intike , fitted a K&N racing air filter cut out the air box got the jetting done J&D i race with a 13 and 48 sprockets, just fitted the new power bowl, now i can eat ktms Kawa’s ,Yams and honda r’s

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