Yamaha Racing News.
Everything posted by graham847
Hi Snakebite - I finally found the diagnostic code mentioned in the Haynes Manual but not where you might expect (i.e. in the fault finding chapter). The Fuel Sensor (7000rpm diagnostic code) and what it means is described in fuel system chapter section 4-26. Great if you know you have a fuel system fault....not so good if you just want to know what 7000rpm indication means to start with...Anyway, hopefully useful info. Cheers
Hi all, Just to update, I took the fuel pump and sender unit out of the tank and found the connection had indeed broken from the green wire to the solder joint at the sender unit. I've attached the photo in case it's useful to others. Re-soldered and will put it all back together next week. Thanks for everyone's input and ideas.
Hi,I have completed further investigations and it appears the root cause is down to the fuel pump and sensor assembly. Looking in the service manual Pins 1 & 3 from the assembly's electrical connector should show continuity (i.e. 0 resistance when checked with a meter.) Unfortunately mine shows open-circuit 100% resistance.To prove this further I jumpered pins 1 and 3 together on the loom side - and the fault cleared, rev counter returned to acting normally. So although I had one rusty Exup cable, that wasn't the main problem.Next step is to remove the fuel pump assembly and see if it can be fixed.Thanks
Thank you mate for that advice, will take a look at those threads
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.
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.
Hi all, I am in the process of restoring a 1997 registered YZF-750R to original condition. The undertray and rear mudguard on this bike has been cut down by previous owner(s) so I am looking to replace this with an uncut original. The question I have is this; Is the undertray for a 1996-onwards bike the SAME part as that used in the 1993/1994 model? Thanks for any answers... regards Graham