RC Valve Restriction

Golden · L Plate Warrior Joined: 01 Apr 2002 Karma :

Okay...

having mechanically de-restricted vipers bike and then determining that the RC Valve or exhaust valve was not functioning as it should, ie in relation to the engine RPM, the next step was to remove radiator and RC Valve cover and physically rotate the valve with a spanner on the end of the valve shaft. First question... this valve seemed ridiculously tight, is it common for them to seize or become sticky? Secondly... is it correct to assume that the nut on the end of the valve pivot, or shaft, is reverse thread and undoing it would enable the assembly to be removed, cleaned and then refitted.

Anyway having rotated the Stiff valve into a mid-open position rather than the low position, which obviously dragged the servo round into the corresponding position, and then reassembling the bike, eager to take it out to see if there was a vast improvement in power, the ignition key was turned and low and behold the servo moved from it's "new" position back into the bugger all power fully shut position. And no surprises during the test ride it refused to budge from said poistion.

HELP. The servo is obviously connected just restricted to the low or shut position! Could you unplug the servo electrical connections and again mechanically open the valve so that this time the poxy CDI doesn't order it shut again as soon as the ignition is turned on?

Any ideas much aprreciated... How many wires and what colour are they running from the RC valve servo? And into the CDI?

Kickstart · The Oracle Joined: 04 Feb 2002 Karma :

Hi

The valves will get stuck, especially if the bike has been run round at low speed / restricted for ages. I would take it out and clean it up thoroughly

The servo motor control unit is quite likely the same as the Cagiva Mito (which is sourced in Japan). This fries the control unit if it seizes or is wrongly adjusted (although normally it seems to fry allowing the valve to open but not shut). To check this is OK, disconnect the cables from the valve and then switch the ignition on. The servo should go through open then closed (but of course without the cables the valve itself will not operate).

All the best

Keith

robxxx78 · L Plate Warrior Joined: 19 Mar 2002 Karma :

I'm having a nightmare! The cable on my RC Valve has snapped so I've got hold of a replacement. Do you think I can get the bugger open! No.
Any advice would be much appreciated, or if anyone has a copy of the workshop manual I'd be your friend for life!

G · The Voice of Reason Joined: 02 Feb 2002 Karma :

I've got the workshop manual for the early NSRs on my website... I don't know if it's similar to the later ones though.
It's about 135mb so if you 've got a slow speed connection it'd be no trouble to send you it on CD. (Click on the WWW icon at the bottom of my post for the site)

Dylan · Trackday Trickster Joined: 03 Feb 2002 Karma :

So no one seems capable of looking around the links i give them Laughing

Here is the EXACT link. I think it means join the blue to the black
https://translate.google.com/translate_c?hl=en&u=https://www.devader.de/&prev=/search%3Fq%3Dnsronline%26hl%3Den

This might help too
https://translate.google.com/translate_c?hl=en&sl=de&u=https://mitglied.lycos.de/nsronline/&prev=/search%3Fq%3Dnsronline%26hl%3Den
Dyl#

Viper · Get off my bloody bike! Joined: 04 Feb 2002 Karma :

Cheers Keith for the info...
Really need some-one with a 2000 uk nsr to have a look at which the wiring coming out of the servo. There are five wires on mine. These are routed to the multiplug cover box thing on the plastic tray under the air-box. Here four of the 5 wires are wired into a multiplug, and one green wire is connected seperatly

WHAT IS ON YOUR BIKES???

Normally turning the ignition on has no effect on the servo. ie. it does not move. However if I unplug this random loose wire then when I turn the ignition on the servo rotates straight to the high position. Yet to see if the bike runs with it disconnected. Neighbours may not take kindly to 2-stroke put-putting at 9pm!!!

Viper · Get off my bloody bike! Joined: 04 Feb 2002 Karma :

Dylan, cheers for the info...

what is the black box? Can't be the CDI as there are obviously more than four wires!!! Can't be the servo box either as after the modification suggested (cutting the wires and joining together) there will only be a power supply to the box and no control. Confused

Dylan · Trackday Trickster Joined: 03 Feb 2002 Karma :

Dunno, cant really read german. I thought it meant the CDI box beacuse i thought these were refered to as black boxes?? Do 4 of the wires match up to the 4 on the diagram as in colour??? I think the way they de restricted them was for them to be open all the time perhaps, like on the DT125 where its open all the time, but this gives no low down power? Have u tried phoning honda UK, they might be helpful, then again probably not!!! If its got a powervalve then there must be a way to derstrict it otherewise the would just plug up the hole with a bolt. Do u know where its importet from, cause if u search on the internet with Google for derestiction guides from certain countries then google can halp translate the page.
Hope this help;s
Dyl