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Showing content with the highest reputation on 11/17/2022 in all areas

  1. Hi everyone On Sunday was out on my 1998 YZF750R when I noticed the rev counter suddenly flick to 7000rpm then drop to show 0 rpm then a few seconds later ping up to 7000rpm again. The actual engine revs and power remained normal and no other issues apparent. On arriving home let the bike cool down, then turned ignition on. With the engine not running, the rev counter started cycling between 7000rpm and then back to 0 then 7000rpm again etc and repeat. Had a look on a online few threads noting that the "7000rpm" is a Yamaha diagnostic indication that points to a problem with the Exup system. So tank & fairings off and had a look. Examined the cable ends at the valve and one was badly frayed/rusty/stiff. Said cable has been removed and a new one ordered. I also removed both cable ends from the servo motor so the servo was free to operate. Then turned the ignition on thinking that the servo motor/pulley would now be free to rotate - which it did and I expected the 7000rpm tacho bounce would not be seen if a seized cable had been the problem. However...the tacho continued to bounce to 7000rpm back to 0...7000rpm again. So I though maybe there is a fault with the actual servo motor. I happened to have a spare motor I bought last year, so plugged that into the loom and turned ignition on. The fault remains just as before. I have checked the electric connections hooking up the Servo to the loom and all are clean and in good condition Beginning to wonder if the 7000rpm code might indicate some other problem. Any more ideas or things worth trying please? Thank you.
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  2. Of have no experience of this bike, but as a member of the Fazer Owners Club (FOC UK), I have seen numerous threads on that site referring to the 7K exup fault. I f I recall correctly, you would have to refit all of the missing parts and then reset (ie zero) the servo motor. It also has to be spotlessly clean and completely free to rotate. You may wish to have a look on there for the FZS1000 Fazer 7K exup fault code
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  3. Thanks for those thoughts. Unfortunately the 1998 YZF is a very analogue beast, and there are just analogue clocks, and as far as I can see there is no diagnostic plug on the loom to plug-in a OBD reader. It might be possible to perform some kind of rudimentary manual "fault" reset via some particular sequence of turning ignition on/off combined with engine run/kill switch position or similar - however, that is a guess and I have been unable to find any information or manual that says there is a way to reset a "fault" condition on a 1998 YZF. The new cables are due in a day or so, and I'll re-install everything, plus connect up the fuel tank and fire her up. Maybe with everything put back together, with engine running the system will reset itself and the tacho 7000rpm bounce will stop I can add that the Exup Valve is completely free to rotate in its housing (I serviced it last year) and the servo motor is rotating when ignition is switched on. Thanks for your input.
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  4. Update. I think I have figured it out. After looking at the wiring schematic I thought the only thing that could be stopping it was cranking over / starting is the starting switch located in the voltage regulator. I took the regulator off, cleaned the contacts on the starting switch and reinstalled it. It worked, but no spark. I cleaned the contacts on the points and now I have spark. It wouldn't start, but I think that is a fuel issue. I am off to get some gas. I will update later. Thank you Neo for pointing me in the right direction.
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  5. Thank you Neo. I will have a look today. I have also attached the wiring diagrams. Thanks.
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