This nsr 250 mc21 seems to be the bane of my life , when I got the bike every thing seemed to work fine I.e when you turned the key the servo primed up ok ! I am in the process of giving the engine a dam good clean along with All the bits you don't see
I've taken most things off and cleaned them up done a few repairs along the way i.e. Repaired a couple of shreaded wires in the loom just below the clocks were they plug together through the clock mounting bracket also removed the PGM to dry clean
Servo casing lifted out so I could oil up and lube all the cables , everything went back together 100%
But now when I turn the key the servo does not prime ?
It starts and runs but no response from the servo , I've been through it with a fine tooth comb trying to find out why servo isn't working when it did previously did , I can get a live feed through one wire where it plugs in to servo , but servo seems dead
Really don't no what else to try
Any ideas will be greatfully received cheers guys!

The RC servo doesn't "prime" as such. If it's already in the correct position when the ignition is turned on, then it will not cycle in the same way a YPVS servo doea.

If you disconnect the T.P.S (with the ignition on) does the servo cycle to the "Hi" position?
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Andy.
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Hi not sure what or where the throttle possisin switch is lol sorry to sound dim , I'm just a DIYer who loves to breath life in to old bikes that need love again , and I've always wanted a NSR and got one that needs love and very temperamental !
The thing is that when I first got the bike the servo primed for about 2seconds
Simaler to my TZR 250 witch primes for around 4 seconds on the turn of the key !
I'll try TPS tomorrow once I work out where it is
Many thanks

if you follow the wire coming from the right side of the carb to a block connector on the right side, fixed to the sub frame, it should be above a green block connector for the air solenoid, if its in the right place. If the servo was in the lo position when you took it apart it wont cycle unless you push it to hi manually or disconnect the TPS. The servo/PV's may have been in a hi position when you hit the kill switch, and that may explain why it seemed to cycle.

Hi guys I've disconnected the tps whilst the ignition is on and nothing seems to hapen also I've moved the servo manually to hi and low still nothing!
Even when reving the engine it doesn't move
I've removed the servo now but not sure what wires to connect to a battery to see if there is life in the servo or what wires to check on the connector plug that plugs in to the servo , any ideas many thanks ..

There is a servo inspection section in the manual, section (19-2) , to test resistance etc. You can also check your TPS by checking resistance with throttle open and closed, cant remember the values, but again there is a section in the manual on that. Failing that I guess its a case of swapping in another servo if you can get your hands on one. If all that seems normal then next port of call would probably be the PGM.

What do you mean when you say that you dry cleaned the PGM? . Fault wise,I'd check are the the loom/unit connectors sound, and start from there.

Hi there, do you try to unplug the servo and mesure with multimeter for any voltages coming? See the wiring diagram for more info.
Hope this problem is somewhere in the wires that goes in the servo.

Hi guys had some time over the weekend,so had a quick fiddle ,but no joy
I took the servo apart all seems fine moves freely,I hooked a 9v battery to the two white wires that comes out the servo motor and it moves fine and when you reverse the polarity ,it goes the other way
Not quite sure what the other 3 wires do that go into the other part , all of the wires have a live although 2 of them only stay live for about 5/10 seconds, I have power to the TPS but nothing happens to the servo if disconnect and reconnect it . All the connections to the PGM show no signs fatigue..
I started and ran the bike , and it sounds crisp but servo doesn't move , the cables and power valves all move freely, don't no what to try next !! Any help appreciated...