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Damn, I just want my bike to run well!!

Discussion in 'Technical and Troubleshooting Torque' started by blue_muppet, Aug 7, 2006.

  1. My bike recently clocked up the big 30k so I booked it in for a thorough tune up. Everything was dandy as I rode away from the mechanics and I felt the new life in my little bike again.

    Alas, a mere 200km after the service (oil change, filter, carby tune and balance) its returned back to badly tuned state. It’s now been just over 500km + plus a fresh tank of good fuel and it’s still being temperamental. It’s clearly missing and it’s slow and sluggish off the line again. There is a big lag in the throttle response and I’m frustrated as hell!

    Should I ring these guys up and ask them to repeat the tune? I parted with a reasonable amount of money to get it done in the first place and I’m disappointed that it hasn’t lasted longer.

    Advice please!

    Thanks in advance people

  2. Wow, that doesn't sound quite right...

    What happened with the fuel filter? Might be about time to change that, also check out the service manual for other things that might need to be checked out (not necessarliy changed or fixed, but just checked)

    Anywho, similar thing happened to my car (yes I know they're different) cleaned injectors regapped and reseated valves (it's an old car). I did the work myself, but around 500km down the track similar symptoms to yours... turned out a badly clogged fuel filter was gumming up the works(that was my suspicion and seemed to be right). It could also be the air filternot allowing the correct mixture to hit the chamber.

    It's a possibility at any rate...

    Another possibility is that something may be allowing the carbs to be gummed up quickly (which would make the throttle slow once again)

    HOWEVER, I'd take it back to the mechanic or a second mechanic for a second opinion.
  3. I would take it back to the mechanic. And complain.
  4. What fuel are you running it on? I figured out the hard way that my ciblet doesn't like premium unleaded for any more than a tank (plugs get fouled).

  5. Take it back and tell em to fix it.
  6. The first tank of fuel ran in it after the tune was the basic shell fuel. I'm onto my next tank now and I decided I would put some better fuel in so its Caltex 98 (The one below vortex)

    I think i'll ring them up today and ask them to take anouther look at it. I'm pretty sure this has resulted through them not doing the job well, not anythign i've done post service.
  7. A hesitation when you crack the throttle is usually plugs and/or leads.

    Stay away from the 98's and if your in doubt, all Shell fuels. They tend to foul plugs. Also, if your bike is an import, then it may struggle on 91 fuel.

    Once you get a full tank of say BP 95 in it, then put a new set of plugs in. I've had 2 sensative bikes and the BP 95 tends to be OK for them.

    Whilst you are at it check all vacuum lines including you oil filler cap. Sometimes a vacuum leak can feal like bad plugs.
  8. If you run premium your bike will peform worse, If your bike was designed to run normal fuel, it will run better on normal fuel, Google it and then realise you have been forking over 5-10c more p/l for worse performance
  9. That's a fair old sweeping statement! I'd rather pay an extra 50c per tank knowing that the worst of the worst wasn't going in there!

    Muppet: The bike will be an import, it will run on whatever fuel you put into it. Forget laying blame on fuel, the problem will be elsewhere. I personally wouldn't (and never did) run the import gsf on garden variety ULP. They were manufactured for teh domestic maket only (Japan), so use whatever octane fuel they had in that era...

    Why didn't the mechanic change the plugs? That would be suspect number 1 to me. My first bike was a gsf, and I can sympathise with you when you say it feels a little 'doughy' down low.

    Ask the mechanics what exactly they did when they say a 'carby tune' was performed. Were the pilot screws adjusted? Doing so may make the bottom end a little more crisp, especially initial throttle inputs/taking off.

    Edit: Just as an aside, I once had a bit of a drama with my Bandit, do you keep yours outside BM, or wash it with a hose?!
  10. Okay the Bandit motor will run on 91 octane unleaded, but not as well - if you're not already using Premium then try switching (don't bother with 98+ octane though). Next thing worth checking would be to open the drain plug in the bottom of the airbox and see what (if anything) comes out. A tiny bit of water isn't really a problem but oil or fuel isn't a good sign. And if you haven't already checked the plugs do that too.
  11. Yep, that was why I asked BM if the bike is often sitting around in the rain, or washed with a hose.

    My airbox filled up with so much oil and water that it could hardly pull over 10k rpm in third gear or higher. There may be some traces of oil in there as on a lot of bikes the crankcase breathers are routed into the airbox.
  12. Thanks for all the replies guys.

    The mechanic did replace the plugs so maybe one of them is faulty. I certainly sounds like its missing on only one cylinder. Checked the drain plug and all is clear.

    I keep it undercover and I know FULL WELL not to wash my bike with the hose because I've had some serious dramas with that before :p

    I got very little feedback from the mechanic initailly. It was pretty much pick-up and pay because I was in a hurry. Its booked back in again this Friday afternoon so they can look back over it again.

    Cammo wrote
    This "doughy" down low business....did you ever fix that on your old bandit?

    Also, as far as I knew, the octane rating wouldn't really affect the performance. Just make it run smoother. It's if you go under the suggested rating that bad things start to happen.
  13. If it's missing on just one cylinder then it could be one of the plugs but also possible it's one of the leads. So when you're checking the plugs make sure you also check the cap which attaches to the plug is firmly attached to the plug lead. If it's anything like mine the plug caps actually screw into the plug leads and it's very easy for this connection to get loose. My bike had that "doughy" feeling down low too but cleaning the carbs or fixing the air leak between the airbox and carbs got rid of that (did both at the same time so not sure which had the most effect).
  14. Nah, I just put up with it. I suspected that the carbs just needed fettling with, but this was some years ago and I wouldn't have known where to start looking back then!

    As JD said, take a look at the plug leads (get the easy job out of the way first). If the bike is missing on one cylinder at idle, start it up from cold and you'll be able to tell which cylinder is missing because one of the downpipes will be a lot cooler (others will be hot!). You can then eliminate factors surrounding the other 3 cylinders (plugs, leads).

    Once you've found the culprit cylinder, check to see that the plug is sparking by taking it out (lead attached), holding it with pliers, and letting it spark on the engine block.

    If all is good in the spark area, then I would suggest either the carbs need balancing again (screws have vibrated loose perhaps?), or the pilot screw on the suspect carb needs adjustment.

    Try this simple stuff first, but if you don't have any joy then take it back to the mechanic. I wouldn't expect to get any special price/treatment since the bike was runnning fine when you left. Good luck!
  15. Sounds like there's some people with a gripe with the oil companies. More octane gives a cooler burn.

    I got a mate thats a petrolium engineer. If you investigate into it, you'll see that ALL fuel (bar LPG) comes out of one pipe. Also, the petrol station owners can request the amount of ethenol they want. Your best bet is to go to a servo that has small tanks, this is because the best fuel (higher octane) evaporates quickest.

    Sounds like the best idea to me.
  16. No idea what that means, but octane rating refers to resistance to combustion by compression. A higher octane fuel than specified for a given engine will give absolutely zero benefit unless you increase the compression ratio and adjust the timing to detonate the more compressed mixture.
  17. Excellent advice Cammo! When I get a spare minute I'll pop out and do those quick checks before I send it back to the mechanic.

    Ro wrote
    Now this is a real worry! If this happened to be true then a flurry of legal action would be taken against petrol distributors for false advertisement. Not to mention we are paying up to 10c a litre more for this "premium" fuel.

    I sure hope your buddy is mistaken. Can anybody else validate this claim?
  18. Approximately three years ago a NSW Govt biody did random tests of servo fuel, and they found up to 25% ethanol in some fuel at 'unbranded' discount vendors.

    Ethanol is a very hot political issue, and governments have been extremely reluctant to regulate it. The NSW Govt called on the Federal Govt to introduce mandatory fuel standards, while the Federal Govt told the states to introduce labelling laws: this has happened in some states.

    The trouble is, as I said, it's political and nobody wants to be seen deterring ethanol, because the farmers want an ethanol market to push up the price of grain. Dick Honan is the CEO of a company called Manildra, which is Australia's biggest ethanol manufacturer and a massive donor to the Liberal Party and a personal friend of J Howard (of course, Labor take plenty from the industry too). But ethanol is not good for engines, so the politicians are largely reluctant to push ethanol hard because they know they will be exposed.

    The Federal Govt mandated several half-arsed 'investigations' to test ethanol fuel and they all found either no advantage or damage. These tests used to be posted on the Environment Australia website, and were carried out by Orbital Engine, and the CSIRO.

    There is an excellent piece on ethanol in the current Australian MC Trader magazine.
  19. i am heavily involved in the petrochemical industry, mostly the bituminous side but this statement is accurate. it all comes down the same pipe.
    therefore negating the 'special' refining techniques of particular 'distributors' it is essentially the same fuel.

  20. a bit of useless info to add.
    did you know it is common for distributors to heat their fuel in storage as fuel expands fairly dramatically upon heating, so the litre you get from the ground may not be a litre in your air temp tank.