Hi All

Has anyone had any experience with DMR_JAPAN's RC Valve Pulley Product F27-21002 (Pic Attached).

It claims the following:

'DMR-JAPAN has remade the special RC valve pulley, which is a revolutionary device for NSR developed and sold by RISEON in the industry!
This is a wide pulley with a safety device (over torque release system) to the conventional wide pulley! When the movement of the cable becomes bad or the RC valve sticks, the fixed clutch of the rotation shaft and the pulley is released, and only the shaft operates to the specified value.
This system prevents the servo motor from chipping gears, motor brushes from burning out, and the PGM from burning out, which is considered to be the biggest bottleneck!'

I was wondering given all the horror stories of PGM's burning out, that it would be prudent to fit one of this to my son's MC18 R5K.

Another reason I have is that we are mating a MC28 R3S engine to a R5K Bike and I am a little concerned about whether we can adjust the required free play in the RC cables (0.2-0.8mm which is not much, but important) or may need cables made up to give the free play?

Lastly, is it a complete No No to move the RC Servo by hand? Reason being to see whether the max. rotation of the RC Servo (either way) matches the full rotation of the RC Valves, to make sure there will be some slack in the cables? Or does the RC Servo not fully roate that much?

Thanks in anticipation.

Phil

I doubt it would hurt to fit one, and DMR appear to make some good products, however I've never used them myself.

Saying that though, since we started strongly advocating regular maintenance of the RC Valve system, and checking its operation & cables, the cases of people reporting PGM failures has dramatically decreased. 20 years ago there would often be several posts a week on the old "Topica Mailing List" about servo failure and "smoking" PGMs... now I don't reckon we see more than a handful a year, and those are often unknown "new-to-the-owner" project bikes with an already damaged PGM and/or servo, or new owners that haven't been around for long enough to have heard all the stories and read the advice!
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Hi Andy

Many thanks for the prompt reply very much appreciated I will go ahead and put one on order. It will be interesting to see how it goes and whether there are any problems like the clutch slipping when it shouldn't (more likely long term though I would have thought).

On the last point below do you think the proposal is a valid one?

'Lastly, is it a complete No No to move the RC Servo by hand? Reason being to see whether the max. rotation of the RC Servo (either way) matches the full rotation of the RC Valves, to make sure there will be some slack in the cables? Or does the RC Servo not fully roate that much?'

Phil

Timely topic. I have one of those pulleys, or similar, purchased from Webbike Japan, purchased for the same reason: MC28 motor with PGM II. It appears that the pulley is larger diameter than stock. Sorry i can't offer any first hand experience yet as the bike is not running. RC valve not working traced back to apparently burnt out PGM unit that was unknown history when purchased.

Supplementary question and not wishing to hijack your thread. I am thinking of sending the PGM II unit to 2T Racelab in Athens for repair and refurbishment. Any feedback or experience with their service would be greatly appreciated. The alternative is to buy another used unit from auction in Japan.

BTW i thought the following video on power valve adjustment was interesting: https://www.youtube.com/watch?v=_3Vt4rh2fGU In this case the adjustment is made by ensuring the valve itself is in the correct open position and then adjust the cables accordingly.

Any comments Andy before i blow up my bike by following this method?

tleighbell wrote:
BTW i thought the following video on power valve adjustment was interesting: https://www.youtube.com/watch?v=_3Vt4rh2fGU In this case the adjustment is made by ensuring the valve itself is in the correct open position and then adjust the cables accordingly.

Any comments Andy before i blow up my bike by following this method?

Well, first of all... it's Revolutionary Controlled Valve!



I would say the CR125/250 setting isn't at all relevant to the setting of the NSR250R RC Valves., so my advice would be to set the NSR250R RC Valves as per our Engilsh Service Manual as follows...



Note:

All models after the MC16 you can simply disconnect the TPS plug and turn on the ignition (kill switch set to RUN) to rotate the RC Valve servo to the "Hi" position, without the need to start the motor and rev it to 2000rpm. (Turn the ignition off while setting the valves.) The setting proceedure is then the same as outlined for the MC16 above.

Once the RC Valve setting is complete, ensure the knock pins are removed, reconnect the TPS plug, and turn the ignition on (ensuring the kill switch is set to RUN again). The servo will return to the "Lo" position.

As a side note, he's actually nicked my diagram off NSR-WORLD to illustrate HRC's setting method! (As used for the TT-FIII race variants.)


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philup_7@hotmail.com wrote:Hi Andy

Many thanks for the prompt reply very much appreciated I will go ahead and put one on order. It will be interesting to see how it goes and whether there are any problems like the clutch slipping when it shouldn't (more likely long term though I would have thought).

On the last point below do you think the proposal is a valid one?

'Lastly, is it a complete No No to move the RC Servo by hand? Reason being to see whether the max. rotation of the RC Servo (either way) matches the full rotation of the RC Valves, to make sure there will be some slack in the cables? Or does the RC Servo not fully roate that much?'

Phil

You can move the RC Valve by hand, but there really is no need to.

The RC Valve can, in theory, rotate in either direction indefinitely, and its position is controlled by the the RC Valve Control Unit (MC16 and MC18 Mk1*) and PGM on 89-96 models, so rotating it by hand proves very little.

There is a very fussy HRC method, but in reality, for 99% of use cases, setting the RC Valves as per the above instructions is more than adequate.

*Before anyone jumps down my throat, yes, the early Mk1 MC18 R2/4J uses an RC Valve Control Unit, and later R2/4Js have RC Valve control integrated into the PGM.

One caveat to setting as per the Service Manual is if you start mixing and matching parts. There are no rules if, for example, you're using R5/6K barrels on an R2/4J, or MC18 barrels on an MC28... I'm afraid you're on your own. The cables, RC Valve shapes, sweep etc. all vary year-by-year, so I'm afraid it's just a case of "suck it, and see"! Just err on the side of loose actuator cables rather than tight!
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Thanks Andy. Very informative as always. Based on your comment about mixing and matching parts from different years, does that make the HRC method of feeling the actual valve position in the exhaust port more realistic in your opinion? Or can the exhaust valve position be accurately inferred from the pulley position?

My bike is intended for track use only. Might i do just as well to just set the valve in the fully open position? I won't be spending much time between 2 and 3,000 RPM.

Hi Andy
Many thanks for the useful tip re disconnecting the TPS plug.

There is so much I don’t fully understand about these Valves eg I didn’t even know what the RC stood for ‘Revolutionary Controlled’ which isn’t a really good start.

The main thing I was worrying about (hence fitting DMR_JAPAN's RC Valve Pulley on a MC18 fitted with an MC28 Engine) was, although setting up these RC Valves using the Honda Manual is ok on Standard configurations, I am very unsure, probably like many others, as to the amount of cable movement given its Rotation, Pulley Diameter, a MC18 R5K RC Servo motor would have when mating up to a MC28 R3S RC Valve making the Servo constantly struggle to either fully open or close the RC Valve when riding.

It would be nice to say they are the same, however, I think the chances of that would be very unlikely at best!

Although DMR_JAPAN's RC Valve Pulley should give some degree of protection I don’t think there’s a magic bullet to solve this issue, unless someone has done it before! hopefully please please.

The only sure way I guess is by setting up a test rig to measure it all, which then would require knowledge of what resistance values are fed back from servo unit to the PGM against RPM, the voltages sent to the servo at those RPM, a variable DC Voltage supply and a way to measure it all, not to mention access to a MC28 and MC18 to compare it all with; or use of a rolling road.

Think I’m going to find a dark corner somewhere LOL.

tleighbell wrote:
Thanks Andy. Very informative as always. Based on your comment about mixing and matching parts from different years, does that make the HRC method of feeling the actual valve position in the exhaust port more realistic in your opinion? Or can the exhaust valve position be accurately inferred from the pulley position?

My bike is intended for track use only. Might i do just as well to just set the valve in the fully open position? I won't be spending much time between 2 and 3,000 RPM.

You absolutely want the RC Valve operational in my personal opinion. The RC Valve is very progressive; it doesn't just wind to fully open at a given RPM... in fact it's not even completely open until almost the redline in some instances.

If the motor is currently unassembled, I would open each RC Valve flap to the HRC specified position, then scribe the cable backplate/holder so once it's all reassembled, you can be sure where the fully open position is, and work from there. You can do it with the motor assembled "by feel" (or even the crude way matey showed on his video), but doing it with the barrels in your hand (with the heads off) gives you a much clearer view to get things back on.

As I said before, err on the side of loose cable tension to start with.
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philup_7@hotmail.com wrote:
The main thing I was worrying about (hence fitting DMR_JAPAN's RC Valve Pulley on a MC18 fitted with an MC28 Engine) was, although setting up these RC Valves using the Honda Manual is ok on Standard configurations, I am very unsure, probably like many others, as to the amount of cable movement given its Rotation, Pulley Diameter, a MC18 R5K RC Servo motor would have when mating up to a MC28 R3S RC Valve making the Servo constantly struggle to either fully open or close the RC Valve when riding....

----The only sure way I guess is by setting up a test rig to measure it all, which then would require knowledge of what resistance values are fed back from servo unit to the PGM against RPM, the voltages sent to the servo at those RPM, a variable DC Voltage supply and a way to measure it all, not to mention access to a MC28 and MC18 to compare it all with; or use of a rolling road.

I'm afraid both yourself and tleighbell are going to have to have a crack at it yourselves. There's just no way to advise on every combination; many of which I've never tried. All I can tell you is we've had two different bikes with at least four different combinations of parts that each needed their own specific workarounds! (The worst to set up by far was an MC28 with a PGM-II and RS250R NF5 barrels & heads!)
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Hi Andy

Many thanks for the sage advice as always much appreciated.

I thought it was a long shot, but if you don't ask etc...

Will definitely have a look at marking up the RC Valve positions and see how it all marries up. Hopefully with keeping the tension on the cables fairly loose we can get the bike running on the road with a fair performance and shake out any other issues, the Bike has been in boxes for 20+ years.

To take it to the next level I think we need to bring it down to Performance Engineering.

Once again many thanks

Phil

philup_7@hotmail.com wrote:
Hi Andy

Many thanks for the sage advice as always much appreciated.

I thought it was a long shot, but if you don't ask etc...

Will definitely have a look at marking up the RC Valve positions and see how it all marries up. Hopefully with keeping the tension on the cables fairly loose we can get the bike running on the road with a fair performance and shake out any other issues, the Bike has been in boxes for 20+ years.

To take it to the next level I think we need to bring it down to Performance Engineering.

Once again many thanks

Phil

Don't forget, you can always get custom cables made up by Venhill should you need to.
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Andy.
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Thanks again Andy for all the great info.

Here is a question that is so dumb i wish i could ask it privately: What is the TPS plug?

And another less embarassing question: with an MC28 engine and PGM II, can i solve all these issues by installing R5K barrels and RC valves?