I've taken the left fairing off, taken off the cover and cleaned the cogs, wd40'ed them and put it back on. The alignment confuses me though. Can you take a look at this image and tell me if this is how it's meant to be? Thanks.
The alignment is done at the valve, which is at the other end of those cables on the exhaust system where the 4 pipes come together. Under the bike, approx below the left footpeg. The EXUP servo-motor that you pictured has no adjustment that I am aware of. There is a "HOW TO" here http://www.cartestsoftware.com/fz1/exupmaintenance.html DAVE
Thanks mate. I figured as much after I posted. I took a closer look, nothing was able to be aligned as such. After taking the cover off I noticed the cog's etc were VERY VERY dirty, gave it a clean and the motor seemed to run ALOT better. I'll take a look at the site and see if I can have a crack at the valve alignment. Thanks again.
You talk about cogs? Sounds like you're taking the motor bit apart. To align the valve, you need to take the cover off the lower bit, on the exhaust, under the engine.
Yeh I was looking at the servo motor, no harm done though. I took the cover off the Exhaust valve pulley cover: It was a bitch to get the bolts off. As you can see it's a little rusted, WD40 did the job. As you can see the pulley fork is lined up over the hole. My Exup should be perfect as it is. When I turn the ignition on, the servo motor resets and both ends of the EXUP cables move without a problem. Very smooth. My problem is that when revving the engine, there's a flat spot before 8krpm. The Exup valve is "Jerky" until it's fully open. The exaust makes a strange noise for a second until the revs get up to 8k. My tacho also lags in this spot. The bike itself goes great, but if i'm riding and downgear and ring on the throttle, for a second the bike slows and feels like it's flooded and then takes off and everything is fine. The other time this happens is when taking off, if i take off fast, it'll sort of lag for a second, then take off. It's only like 1.5 seconds that this lag takes place. Any idea what this is? Like I said, when the servo motor resets both ends of the Exup turn fine and very smoothly. But when revving the engine it is jerky and I think this is the problem. What could it be?
Okay, so if you have gotten this far, you'll understand what I'm going to tell you. Advance the valve about 3 full turns on the open cable and bring up the slack in the return cable. If this doesn't help any, I'd start with a good carb cleaning as well as a complete change of fluids and filters. Get all of that done, run the bike to about 12 grand in 3rd and kill the engine and pull in the clutch at the same time (plug chop). Check your plugs. Put in a fresh set and tell us what you find.
Thanks for the reply FZR Dude. What will this do exactly? I'm not actually sure how to rotate the valve. Do I need to remove the cables from the pulley and then turn it by hand? I had a major service about 5 months ago, had air filter, oil filter, coolant, carbs, shims, plugs etc. Had the carbs re-tuned only 3 months ago because it was running lean. Something I might mention. At 8k rpm the fork moves to this point: Should it be moving all the way around?
I was talking to titica on the OCAU forum who suggested it might be the servo motor. Under pressure the motor might struggle. I tested the theory by tightening the cables so there was barely any movement. The motor would barely move. I also revved the engine and put my finger on the pulley with a little pressure... It didn't want to move much. Do you think this could be the problem?
Can definitely be. With the bike in the off position, turn the valve by hand, either at the valve itself, or at the servo motor. Turn the ignition on. The servo motor should reset itself to the position shown in the photo above. One thing you can try without doing harm to the bike it to disconnect the cables at the valve and wire the valve in the open position. Take it for a spin and see if that doesn't cure one issue but possibily create another lower in the rpm range. Yes, the servo sounds like it might be stuffed. Oh, and to answer your question about the three turns, it'll cause the valve to become fully open a little eariler. If you trace the cables from the valve back to the servo, you'll find some adjusting nuts.
FZR Dude. The motor does reset itself. I've adjusted the cables a few times and tested whether this makes much difference. Obviously too loose and you'll have a problem, but generally the tighter the better. I have probably 10mm slack which works best when the motor is resetting itself. I have tested different slacks with no gain. I'm certain the slack is sufficient. I might disconnect the cables next weekend and leave the valve open to see if this makes a difference. If it does then i guess i'll replace the servo motor.
Just another thought on the EXUP valve - I think you may have answered your own question - take the cables off the valve and wobble the pulley to see if the bushes are worn. It might be easy to turn without the engine running, but bind when there is exhaust pressure pushing on the valve. DAVE
How would I know if the bushes are worn. The pulley moves in and out if i wobble it, just slightly like there is a 5mm gap. Is that normal?
Is there any lateral movement rather than in/out ??? does it feel like its grabbing when you rotate it with the engine running?? (get some one to put a few revs on when you do this!! ) Does the servo get jerky when the cables are disconnected and you rev it ??? Just for your info, my servo starts moving at around 3000rpm and is fully open at 8000rpm DAVE
No lateral movement, only in/out. I haven't actually looked at the pulley's while the cables have been taken out. If I take the cables out, and the valve remains closed while i rev the engine... Wont this cause problems anyway? Should I wire the valve open while I do it? I guess you're just trying to determin whether or not the servo motor is receiving instructions to open the valve right? Dave how do you know if it's open entirely? Did you see my indicator above? Are you saying at 8krpm your pully is further than that? In this case, it means that above 8krpm the valve is not open fully when it should be, which would obviously affect the engine's performance.
If you get a mate to rev it 4-5000rpm and you try turning the valve manually, you will see if it is jambing when it has back pressure on it - wind it from park position to fully open. Mine was wired open when i got my bike and it ran terrible below 6000 at times - it seemd like it was flooding, etc. I cant remember the exact position it should go to, but when you wind the valve by hand, it will stop when it's fully open. Then you will know approx how far it should go!!! Try putting some light load on the servo without the valve connected, rev and see if it jerks - compare to the reset sequence with load on it. 1)trying find out if the valve is sticking 2)whether servo is faulty 3)or could be whatever drives servo (CDI I think) is faulty best of luck DAVE
Thanks mate. Like I said, when the servo motor resets, the valve opens fully without any problems at all. From that we can deduce that the valve is not obstructed because the servo motor produces little power and still manages to manipulate the pulley to open the valve and close it again. I turned the pulley when revving the engine and noticed that it moved, I also held the pulley in place and noted that it had great difficulty in moving. The valve doesn't open all the way around until about 14-16 rpm. From that we can deduce that it is the CDI and/or servo motor. Don't you think? What exactly does the CDI do? Thanks for your help dave, muchly appreciated. I might write a comprehensive how-to (with pictures) for the FZR250 once i'm done with this.
CDI is short for capacitor discharge ignition. I do not have a wiring diagram but i guess that the servo motor is driven from the CDI as it "KNOWS" what revs the engine is doing and adjusts the servo accordingly. I think the next step for you would be to borrow a CDI and servo, trying one at a time and see if that helps, as it sounds like it may be your problem. Maybe a few other members can check their servos and report on the rev range that they operate over??? Mine is '89 2kr and they may vary on later models. DAVE
I had the same idea. I think a friend of mine has a spare servo motor, i'll see if I can whack it in, if it works, bingo, if it doesn't i'll try the CDI. Thanks for all your help. Appreciate it.
Question.. Like I said before my tacho has a problem where i can rev the engine but the tacho doesn't move, then all of a sudden it fly's up to 8k rpm and continue normally. It wont have a problem coming back down to 3krpm though. I can go between 3 and max no problem, it's only getting the bike from stationary up to 8krpm, then riding its fine. Would this be a CDI problem? In that case my exup might be CDI related rather than motor like we first thought...
