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Won't Rev

Discussion in 'FZR250.com - Archives' started by touki, Oct 30, 2007.

  1. touki

    touki New Member

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    Hi guys,

    This is sure to be my first post of many as i am new to the motorcycle game.

    I bought a FZR-250 '89' 2kr with EXUP with 13,000 km's on the clock (genuine? who knows) and because it was hardly ridden, the battery wouldn't charge so i replaced that. There is also a rattling sound from around where the EXUP valve is, does this mean it needs a tuneup?

    Yesterday it was a hot day and rode to the shops, when i stopped the temp gauge was basically in the red came back half an hour later and jumped on to go home and the bike would not rev. I legged it home going about 40.

    It can rev to about 8k and the hotter the bike gets, the worse it gets. It starts to miss and if i give it full accel, it will just stall.

    I have also noticed a rapid clicking noise that seems to be coming from just in front of the fuel tank that will speed up with the revs which made me suspect a coil/ignition issue?

    I was putting premium but after ringing my local bike place they advised me that with the old school carby bikes that can cause blockages and could require a strip down/rebuild.

    I was going to do a full service and reassess the situation, but if any of you guys could shed some light that would be great. I have read extensively on here about various issues, but couldnt find any like mine.

    Thanks!
     
  2. motoride

    motoride New Member

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    Sounds like you need to check your cooling system first. Is there coolant in the radiator? Do you have a radiator fan, if so is it working? Is the radiator blocked?

    What type of fuel did you put in? Shell Optimax is apparently a no-no for some bikes.

    You have quite a number of problems but I would start with your cooling system.

    Let us know. oh! and welcome!
     
  3. dave

    dave Well-Known Member

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    Over heating is usually a thermostat issue. Pull the thermostat out and check that it is functioning properly. Test in boiling water as per the manual. The thermostat is located behind the radiator on the RHS of the bike.

    Here is the the relevant section of the manual
    <!-- m --><a class="postlink" href="http://twisted-elements.com/fzr250/chapter06_cooling.pdf">http://twisted-elements.com/fzr250/chap ... ooling.pdf</a><!-- m -->
     
  4. touki

    touki New Member

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    Thanks for your replys

    I am quickly learning about the bike

    To clarify whats happening. When i start the bike cold after it has been sitting for a while i can ride it normally and it'll redline etc, however after i stop and start again or ride for more than five minutes, the bike will struggle to rev past 8-10 and get over 40kmph.

    With the cooling system i believe the problem is my thermo not working, not once has it come on, i am taking the bike to the mechanic this week to get the carbys cleaned and balanced i will get him to check it out. When does it kick in for you guys?

    Solved the clicking, my leads are dodgy and were shorting against the casing, electrical tape solved that, but i would like to replace, went to local bike shop and they couldnt help caus it was an import. Anyone know where to source some?

    Checked the plugs and they're fine, so i believe its a fuel issue.

    I did put one tank of optimax through, i hate it, but its all that was available. Having spoken to a few people and read the posts here i am now just going to run regular unleaded.

    I have replaced the fuel filter but i am still having the same problem.

    I thought the problem would lie with the tank or carbs, the latter being more likely. So for that reason i will get it looked at this week.

    From when i first got the bike, there were some flatspots which i think can be attributed to the carbs and being the '2kr' model i read that these are pretty flimsy anyway so a clean will hopefully work some magic.

    I am about to embark on my first oil change, bit of a pain having to remove the exhaust...
     
  5. dave

    dave Well-Known Member

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    Don't confuse the thermo switch witch runs the fan and the thermostat that controls the water flow. Lack of water flow will make the engine very hot very quickly, even when riding at speed.

    The fan should only come on when riding around town at low speeds when there is not enough air flow to cool the radiator, from memory just before the gauge gets to the red.

    At normal highway speeds (above 60k ) the temperature gauge should not get above 3/4 way to the red line. On my ex FZR the fan was connected to a switch so it could be turned on manually ( I suspect the thermo switch had failed and been bypassed by previous owner )
     
  6. touki

    touki New Member

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    I'm not confusing the two as my previous two cars have been rotors and due to their tendancy to overheat i am quite familiar with the cooling system. When i have time i will replace the thermostat for peace of mind.

    However i believe my problem lies with the thermo itself, either the switch or it isn't working because not once has it come on. The only time heat is an issue is when i am in heavy traffic or it's a really hot day, the rest of the time she's fine. Up until i actually looked hard for it i didn't realise there was a fan!

    Thats interesting about the thermo switch, i might do the same and just turn it on on hot days, its just a question of switch placement caus there aint a nice fat dash that you can mount it on.

    On a seperate note, where are the fuses located?

    Thanks for the help
     
  7. dave

    dave Well-Known Member

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    Ok Touki, I was not sure if were were talking about the same thing, but you have clarified that. My switch was located on the frame next to the radiator cap, using one of the bolts to mount a bit of AL plate with a toggle switch in it.

    I think the fuses are located under the seat, but from memory there are only a couple. Perhaps someone else can help with that one. I sold my bike a year ago so I can't have a look for you. Hope you get it all sorted.

    As for the fuel do not use optimax in the FZR a it is a denser fuel and the bike will most likely run rich and foul plugs, run like a pig, etc. The FZR will run nicely on unleaded.

    Here is a portion of an old post on fuel

     
  8. touki

    touki New Member

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    Thanks for that, I cringe when i fill any vehicle with opticrap, i'll be sure never to put it in my bike again. Shes booked in for tomorrow to get the carbs done, i'll report back as to the outcome.

    EDIT: Went to see the mechanic and they basically said i'd be up for 10hrs labour @ 100 per hour to fix the bike so i am running carby cleaner through the fuel which has made an improvement.

    One positive from the visit was the mechanic sprayed carby cleaner on each of the exhaust headers and established that the 3rd cylinder wasn't firing. I brought it home and replaced the spark plugs, which made an improvement, but after a 15min ride i had problems again.

    I believe i need new coils as i have been 'zapped' testing them, once testing cylinder 1 and once cylinder 3 and no 3 was much weaker.

    On a seperate note, i played around with what i thought was the thermo fuse and sure enough, when the bike got hot it turned on! Old electrics i guess...
     
  9. touki

    touki New Member

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    Well a few weeks, and $500 later the problem was silicone in the emulsion tubes, all 4. Dodgy home rebuild gone bad i think

    once we blew the #### out shes running like a dream!

    so happy...
     

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