those with 04 RXP's or 04 RXP ECU's in conversion skis and are only getting 7600 rpm

[Ivaan]

Jerry,

I installed the piggy back wire, but when I took the ski to my local dealer there was no update available?? What is the name/serial number of that specific firmware update for the '04 ski's?

I am only getting around 7200rpm, so there must be something I'm missing?

[JLewis]

ivaan, i thought if your using the rotax racing ecu you don't need the piggy back wire, from what i'm understanding at the beginning of the thread.

[flnsx]

Is the knock sensor just plug and play? ie, is it easy to install?

What does conversion skis mean? Non OEM?

[kongen867]

flnsx...

Yeah i wanna know that as well... Im from denmark so my parts are a long time to arrive and they shipping is expensive so it would like to know what i need ? I have a Apple Green RXP 2004

[brent]

After doing some digging and resistance checks on my 05 I found out that the update also affects 05 models. The engine harness part number 420664951 is used on.

Where Used: [420664951 (Engine Wiring Harness Ass'Y)]
Challenger 180 4-TEC SCIC, 2005
Challenger 180 4-TEC TOWER, Edition 1, 2006--
Challenger 180 4-TEC, Edition 1, 2006
Challenger CS TOWER, Edition 1, 2006
Challenger CS, Edition 1, 2006
GTX 4-TEC, LTD SCIC, 2005
RXP, 2004
RXP, 2005
RXT, 2005
Sportster 4-TEC SCIC, 2005
Sportster 4-TEC SCIC, Edition 1, 2006

So does the update(harness adapter and reflash) actually apply to all these models, or just the 04 RXP? Im troubleshooting an 05 sportster scic with rpms stuck in the 72-7300 range and wondering if its one more item i can add to, or subtract from, my list of possibilities to check....

**UPDATE** Installed piggy back adapter on my 05 Sportster 215 . CEL came on and rpms did not change. If anyone needs a piggy back adapter I have one cheap!

[warner0308]

heres my question, does the rpms stay after its been flashed, or will they gradually go down? would i run 7950 rpms and 10 hrs later only run 7500? thanks for any help

[flnsx]

I received an adopter the seller said was new but the pouch was open. Should the tag on the adapter have the part number 278002050? The one he sent me says 97323*r00* and below that number it says 665340

Did he sell me the old part number that I already have on my 04 RXP?

[Flyer5]

Reviving an old thread. The adapter harness is getting difficult to find. Has anyone just added a 220k ohm resistor to the existing wiring? It seems senseless to spend $50 if a 0.35c resistor just needs to be added. Thanks

[Derek45]

Reviving an old thread. The adapter harness is getting difficult to find. Has anyone just added a 220k ohm resistor to the existing wiring? It seems senseless to spend $50 if a 0.35c resistor just needs to be added. Thanks

They sell them on Ebay just type in 121234560786 in search or the part # and this should pull up for $35

[ApriliaRyan]

Dude I'm with you on this one. If it's a simple resistor which it sure looks like why not just splice in?! It's just a wire if it doesn't fix it and wires are fixed hella cheap. I'm all about DIY on stuff like that. Kinda like 10k mod on 7.3 ford diesels. Lol.

[ApriliaRyan]

Update , tryed making a jumper and it did jack. So I bought the real piggy back harness and no changes.Is this maybe a wear ring issue or prop pitch not right causing low rpms under load? Out of the hole and in the air I see 8k rpm but no other time. Rough water im like 60mph and smooth can get a few more . Havent gone too our SeaDoo/ Harley stealership to see if the ecu has been flashed and what they would rape me to check and or do.