Hi guys,

Can anyone tell me the correct placement of the cable ends at the housing on the servo body? Put them back the way I thought they went, but they just don't look right.

Also, the servo I took off (stuffed) has 1992 stamped on it, and the servo I'm putting in has '89. I'm assuming MC18, and the pulley wheels are slightly different. Are there any other differences?

Cheers

The pic below may help you. Its not my bike and I've not got to grips with RC servos before, so can't vouch for 'correctness', but it may point you in the right direction.
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Rich
MC21 Track Bike / RS250 NF5 'Spencer', NX5 'Cadalora' & NXA 'Aoyama' / RS500 / Two Brothers Racing RC30

I'm OK with the general routing up to the servo unit, I just wanted to double check the positions of the cable ends in the housing before I try to adjust them. There are four positions on the servo body, which cable goes to which position?

It seemed a fairly straight forward question.

Both of cables from one of the valves goes to the top holes, front cable to the front pulley hole, back one to the back hole and other valve the same on the bottom.

I think the question is which cylinder is on the top and which one is on the bottom. I will have to check, but from memory I think the rear cylinder was on the bottom of the pulley on mine. I found that the cables sheaths are a snug fit on mine with the turn radius required.

That is what I was after - they didn't look quite right (some appeared too tight, the others too loose), before I adjusted all the cable tensions. This is a bit fiddly, it's the first time I've worked on an an NSR. I'd rather check twice, then do it once.......

Much appreciated!

OK, I have the cables routed correctly. The index mark on the cable drum/pulley was pointing to the "Lo" mark on the servo body, from when I plugged the servo unit in and turned on the ignition.

I have adjusted them (according to one of the posts on here) by disconnecting the TPS, turning the ignition on (pulley rotated to "Hi" mark), then adjusting the cables until the holes line up using a 6mm drill bit as a guide. I know this is the quick, imprecise way, but it'll do initially.

So, once the TPS has been reconnected, and the ignition turned on, what position should the cable drum/pulley be at? The index mark on the pulley is pointing just past the "hi" mark on the servo body. If I turn the throttle a few times, there is a faint hum from the servo motor (but no movement). Does this setup sound correct?

FYI, when I bought the bike, the previous owner had gutted the servo, rigged up a manual system of operating the powervalves through a cable off the carb throttle drum. The spare servo I had is off an MC18 (I think), and has a slighly different pulley/cable drum, both of which are different to the one pictured above.

I can't take it to a bike shop, as the nearest NSR workshops are over several hundred kilometers away, and Honda Australia refuse to provide information on grey import bikes.

Indestruction are at the bottom of the Engine tuning guide.

First time I did it by the mark's on the pulleys and its turned out a bit different to the hole method, it doesn't seem to be very accurate doing it both ways compared to setting to the HRC method.

I found when doing it the HRC way the servo cycles to full open with the TPS disconnected just off idle s you don't need to rev it to 10,000rpm. It might be different with a HRC card.

Pic of my full open servo and the valve at marks aligned position I think. Ill check tomorrow.


http://homepages.ihug.co.nz/~m-gray/pv%20servo.JPG
http://homepages.ihug.co.nz/~m-gray/power%20valve.JPG

zxcvbnm wrote:
I found when doing it the HRC way the servo cycles to full open with the TPS disconnected just off idle s you don't need to rev it to 10,000rpm. It might be different with a HRC card.

You can rev the motor to 2000~3000rpm to get the same effect. (Something that wasn't known 8 years ago when I wrote the original version of the guide.)

If you are unsure of the routing, connect only one cable to one RC Valve pulley and then test the movement of the servo and RC Valve. When you are sure it's connected properly, connect the opposite cable. From memory I believe the bottom cables on the servo route to the top cylinder -- do these first.

If there's undue strain on the servo it will blow the RC Valve circuit in the PGM, and a "humming" from the servo motor is NOT a good sign in my opinion!
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Andy.
NSR-WORLD.COM

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Readjusted everything again, as it was slightly off. No sound from the servo (might have had a cable a bit tight??).

Bike ran better off the bottom, and seem to have found a powerband at 8k! Happy days. This suggests to me that the servo and PGM (servo control circuit) are both operational.

Thanks for the advice.

Yes, most likely tight cables then.
_________________
Andy.
NSR-WORLD.COM

Please keep all responses to Forum posts on the Forum so that others may benefit.

Please DO NOT PM me for technical advice. My time is precious, and you will probably receive a faster response on the Forum anyway.

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