2006 CR250 RC Valve issues [With Video]

Related:
Create New Tag

8/15/2018 9:15 AM

Hey guys

Started having some troubles with my power valve on my 06 CR250. At about 3/4 throttle the power would "pulsate" for lack of a better word. Went through the carb, the engine, and all the electronics before I removed the RC Valve cover and found that when I would get to about 3/4 throttle the valve would just pulsate and didn't look like it was opening up fully at WOT.


Opened the servo motor and found the rust bucket that some would call an electronic motor. Did some research and got the RS365SH replacement motor.


The reason I'm here is to ask if the wire polarity makes a difference. Obviously I would think it does, but does the replacement motor label +/- poles, and also which wire is + and which is -. I did my research and saw nothing of the polarity.

Didn't think to order a replacement brass gear, so has anyone been able to reuse the one that's pressed fit on the shaft?

One last thing, would replacing the Mikuni with a Keihin (aka unplugging the TPS) be my issue? Didn't have troubles at first but now I'm second guessing myself.

|

8/15/2018 12:32 PM

I've run a Keihin on s few CR250's with the RC valve (electronic PV) and never had issues. Then again, I had an '03 CR250 that had a servo motor go bad and it had the stock Mikuni carb on it and never had a Keihin put on it. The motor/cable assembly would pulse and randomly move like it had a mind of its own. Needless to say, it took a while to diagnose. lol I think sometimes the motors just go out randomly...

|

8/15/2018 1:37 PM

DynoDan22 wrote:

I've run a Keihin on s few CR250's with the RC valve (electronic PV) and never had issues. Then again, I had an '03 CR250 that ...more

Did you change the motor or the whole Servo Assembly?

If you only changed the motor, do you recall info on the other questions I had?

|

8/15/2018 4:55 PM

I replaced the whole servo motor assembly. Sorry I didn't address that. I just wanted to point out that the Keihin carb swap/unhooking the TPS won't cause a servo failure.

|

8/15/2018 7:02 PM

Here is a good read on replacing the oem servo motor with a Mabuchi RS365SH.

https://thumpertalk.com/topic/1124517-cr250-rc-valve/

|

Speak softly and carry a big stick.

8/16/2018 3:24 PM

HELP

replaced the servo motor and it’s still fluttering See Video. Unless this is normal and my problem is elsewhere..?

|

8/16/2018 6:20 PM

I'd check the wiring that goes from the ECU to the RC motor. I've seen people post about having loose wire connections going to the RC motor.

|

Speak softly and carry a big stick.

8/16/2018 6:32 PM

I have seen this happen when the cables are not adjusted correctly as well.

Paw Paw

|

8/16/2018 6:53 PM

cables are brand new and tensioned correctly.

i’m convinced it’s the potentiometer. does anyone know if there is a replacement or if i just need to buy a whole new assembly? i’d hate to do that since i just changed the motor and all. Photo
Photo

|

8/9/2019 1:07 PM

Did you ever figure this out?

|

8/9/2019 3:48 PM

Check all the gears in the RC valve gear reduction. They are plastic and can strip. If they do strip, the powervalve will flutter because it's trying to find the correct position via the potentiometer but the stripped teeth won't allow it.

|

8/9/2019 4:44 PM
Edited Date/Time: 8/14/2019 12:04 PM

I opened mine up and everything looks good, not even a drop of water intrusion. Motor seems to work fine when hooked to a battery, the problem I am having is after starting the bike the servo motor parks the power valve in the open/high rpm position and then will move it randomly through the rev range, never really having any consistent movement pattern vs RPM.

|

8/14/2019 11:46 AM

I have a 07 with a good bit of motor work and I noticed in the past with the cover off it had some fluttering but not quite as bad as the one in the video but I was still concerned. On the track the bike runs perfect and tells me the RC valve is doing what it’s suppose to do at the right time. The only thing I see is that when riding the bike on the track under a heavy load it’s working like it’s suppose to work, having the bike on a stand in neutral free reving it the load conditions are much different causing the valve to show it’s fluttering for some reason. Is the CDI box seeing this unloaded condition causing the fluttering through the electronics ??? I’m by no means a Honda electrical guru. Lol I’m just throwing out some ideas based on my own bike and experience. I see where you where having a issue around 3/4 throttle where you felt the bike pulsating. Is there anyway you could try a different CDI box just to eliminate the possibility of the box sending the wrong signals that control the servo?

|

8/14/2019 7:07 PM

Check your wiring harness coming from the ECU. My 03 was doing something similar. Thought it was carb related but ended up being a broken wire in the harness. Fixed the wire and the problem was solved.

|

No brains, No headaches.

8/16/2019 3:50 PM
Edited Date/Time: 9/30/2019 4:04 PM

Swapped the servo with a known good unit and it worked the first time I started it. Let it sit for an hour and come back to start it and now it doesn’t work again; doing the same thing as the original server motor… The funny thing is it seems to work correctly every one out of six or seven times. Looks like I’ll be diving into the wiring later this weekend.

|

8/20/2019 8:03 AM
Edited Date/Time: 8/20/2019 8:05 AM

For future reference, I found my problem. The green wire @ the ECU was hanging on literally by two strands, I broke the wire for the pic to make it obvious. The black/yellow wire looks like it’s next so I’ll fix those two and see what I gets me.

Photo

|

8/20/2019 7:23 PM

Let us know if that fixes your problem.

|

9/27/2019 8:35 AM

Hi everyone, i have an issue with my 02 cr250.
The valve dont move or move randomly. I check everything and im suspected the potentiometre in the servo motor, I wanna know if its possible to buy only this piece.

Thanks for your answers. ✌🏽

|

9/28/2019 6:50 AM
Edited Date/Time: 9/28/2019 6:59 AM

biko31 wrote:

Hi everyone, i have an issue with my 02 cr250.
The valve dont move or move randomly. I check everything and im suspected the ...more

You can not purchase only the potentiometer.
If you're looking to purchase only the potentiometer, you're obviously looking to save money- no problem!
Go to eBay and type in "CBR600RR servo".
You'll find dozens available for only a few dollars.

If your CR250 servo motor is faulty, corroded or damaged-
Remove the CBR servo motor from the CBR case.
Install the CBR servo motor into your CR250 case and use the original CR250 plastic gears.
The CBR potentiometer and Sumitomo electrical connector can be used. You may have to rearrange the electrical wires in the connector from the CBR to match the CR but the connector will work.
Cheapest reliable way of changing the CR250 servo motor since the vast majority of CBR motors have obviously never been exposed to dirt or mud and have a higher probability of being corrosion free than purchasing used CR servo motors which have been exposed to dirt, mud, and pressure washers.

If your CR250 servo motor is OK- you can remove the CBR potentiometer and splice/solder to CR250 wires. The CBR potentiometer fits in the CR250 case.

|

9/28/2019 6:22 PM

biko31 wrote:

Hi everyone, i have an issue with my 02 cr250.
The valve dont move or move randomly. I check everything and im suspected the ...more

Go back to my reply above. Check for broken wire in the harness.

|

No brains, No headaches.

9/30/2019 7:27 AM

biko31 wrote:

Hi everyone, i have an issue with my 02 cr250.
The valve dont move or move randomly. I check everything and im suspected the ...more

40 wrote:

You can not purchase only the potentiometer.
If you're looking to purchase only the potentiometer, you're obviously looking to ...more

Ok, thank you so much for your answer, this might be the best way to fix this. I just order a cbr servo, i will put it in the cr250 and see what happen.

|

9/30/2019 7:28 AM

biko31 wrote:

Hi everyone, i have an issue with my 02 cr250.
The valve dont move or move randomly. I check everything and im suspected the ...more

Keith72 wrote:

Go back to my reply above. Check for broken wire in the harness.

Everything seems to be okay im going te double check. When i rebuild it.

|

9/30/2019 4:06 PM

JMCR250 wrote:

Let us know if that fixes your problem.

Broken wire(s) fixed my problem.

|