My FZR (2kr) has always made a "chuga-chuga-chuga" (thats the best I can describe it :/) sound at low revs, but lately it's gotten worse. (When I bought it a few months ago I could hear it, but it wasn't overly loud, and I assumed the EXUP bushings.) It's now very audible at low speeds, and it increases as I accelerate. (It *appears* to disappear at high revs, although im thinking the noise happening at higher frequency + the air going past my ears means I cant detect it?) If I clutch the bike and rev it, it seems to stop - which leads me to believe it is not the EXUP as I originally thought. Also, as of the last 2 days I've noticed a "clicking" sound as I decelerate (the clicking is similar to a car clicking as it cools down after a good drive - metal cooling?). The sound is only there when the engine has load on it as it decelerates (i.e. I clutch it and the sound stops). Since both of these noises are only when the engine has load on it I am *thinking* CAM chain, (this is based on no mechanical knowledge whatsoever ), so would be grateful if anyone had any suggestions? (BTW I fully intend to pull the cover and wires off the EXUP valve to confirm it is not the problem, but I've been super busy lately and unfortunately the bike is my only vehicle so I cant take a couple of days to try and do a really thorough job - bring on the weekend)
Took the EXUP cover off today and it appears to be moving fine (I didn't disconnect the wires though)...but all in all it doesn't look like its an EXUP problem.
If it stops when you pull the clutch I would say it is clutch or gearbox related. If you only notice when riding could be chain or sprockets. The EXUP rattle is is more of a buzz/growl at low rpm and usually disappears at hi revs.
The chain does have a tight spot (I'm running it rather loose so it's not too tight on that spot) and the front sprocket is a little hooked, so I ordered one - just waiting for it to arrive now! Bought a 600mm breaker bar just for the front sprocket, only to find I could undo it with a normal ratchet <!-- s --><img src="{SMILIES_PATH}/icon_sad.gif" alt="" title="Sad" /><!-- s --> haha. Gearbox/clutch will be dumb...my gearbox isn't feeling tip-top actually. Keeps hitting neutral patches between gears, and theres a big 'loose patch' (backlash) when I change gears - I'm hoping that's just because the chain is rather loose though...
Gear train lash will be improved with the new chain - you are correct. Also, inspect the sprocket carrier dampers for excess play; they're rubber, and wear. As for hitting false neutral between gears, check your shift pedal for proper adjustment - if it's too high, you will often not lift it high enough for proper engagement.
Put on a new chain and sprockets today - problem fixed. After your comment dave I realised I was so used to the sounds that I couldn't tell you if it disappeared or not when i clutched it, so I tried it, and it disappeared. So all today i was sitting there thinking, "dang, of course its not the chain if the sound disappears when I clutch it" haha. Now I've just gotta bypass the thermostat (pretty sure its only working intermittently), clean my magneto (battery doesn't seem to be charging all the time), check my fuel tap (get power surges on the main flow, all good on the reserve flow), and maybe get a new front brake disc (slightly warped.....they're too dang expensive though ) Cheers for your input boyz. EDIT: By the way, did the FZR250's come out with 2 fuel filters? I have one before (what I assume is) the fuel pump, and one after...from what the guy in the shop said it should only have one?
The FZRs came with 1 filter. The fact that you're getting fuel starvation on main plus the previous owner put on an additional filter says to me your tank is full of crap, and the intake screen is fouled. Drain it, clean it out, clean the intake screen, put on (one!) new filter. Thermostats are cheap, engines are expensive. Swap it out. Take your part to the local car parts guys, see if they can't find the same item for a fraction of what Yamaha wants - example. If you battery isn't charging, check your levels and get it tested. Make sure you don't have a trail of crud from one terminal to the other; depending on what it consists of, this can discharge your battery overnight. Check the running voltage across the battery terminals at 5000 rpm, it should be 13.5-14.5vdc. If that doesn't work, stop the engine and unplug the 3-wire connector from the alternator (not magneto). Start up, rev to 5k rpm; measure the voltage across each pair of white wires. You should see 30-60vac. If you do, your voltage regulator has failed low - annoying, but better than failing high and burning out your tach, ignitor, and lamps (the 400s and 600s are infamous for this). If you don't see this voltage, then you have an issue with your alternator. Replacing brake rotors hurts the wallet; replacing flesh just plain hurts. Your call; there's lots of people parting out 250s that would be happy to take your money. Here's one on EBay, 40 Euros.
When i say thermostat, I was actually meaning the temperature gauge output coming from the same area (my gauge is the part that's only working intermittently - ive confirmed with a multimeter that there's no volts there when the engines warm). I actually have no idea if the thermostat is working fine or not - but ill test it all the same.
Have a read of this guide to testing temperature sensor and gauge. <!-- l --><a class="postlink-local" href="http://fzr250.com/viewtopic.php?f=30&t=3423">viewtopic.php?f=30&t=3423</a><!-- l -->
Tried to remove the temperature sensor today and stripped it's head in my spanner <!-- s --><img src="{SMILIES_PATH}/icon_sad.gif" alt="" title="Sad" /><!-- s --> Gunna have to remove the block it sits in how and put it in a vice....more work. Question though, will removing the temperature sensor let coolant flow out? And same question for the radiator fan switch temperature sensor. Both appear to be buggered, and both screw into the same block.
Yes, both are wet - remove the rad cap, and pull the hose down at the water pump. That'll pretty much drain the system.
