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Carbs/engine issues

Discussion in 'Technical and Troubleshooting Torque' at netrider.net.au started by thegutterpoet, Nov 5, 2014.

  1. My 99' yamaha r6 was rescued from a rather unsavoury chap 4 years ago. I had the impression that he had taken less than great care of the beast, yet was gloriously impressed with it's raw power. So I paid the money and off I flew.

    During the last few years I have finally learned how to do my own oil and oil filter changes, air filter cleaning and replacements and rear sprocket and chain cleaning at close to regular intervals. A year or so back I had the valve clearances adjusted, some shims replaced and the carbs synced.

    Although now I ponder what quality of work was carried out by these particular mechanics at Gassit Motorcycles in Fairfield, for I had a horrendous time with them earlier this year when taking the bike in to have a new front tyre, new spark plugs and fuel filter installed. Their mechanic suggested that my carbs seemed a bit 'fluffy'. So I agreed for them to resync them.

    They returned the bike to me with the revs hanging horribly. Three times I took the beast back. First I was told that the carbs had been checked without even removing the tank, and they were fine. Which made no sense to me, for how the hell could they get to the carbs without removing tank and airbox? Second time I took it back, they told me it had been resynced and was perfect, yet the revs were still hanging horribly. The third time was the cream of the crop. The 'mechanic' was returning from a test ride of my bike as I appeared and I spoke with the shop owner. He flew into the workshop at high speed, then wheeled the bike out by its mirrors, letting go as he kicked out the stand so it scraped along the road. He seemed irate.

    It took the owner to demand he remove his helmet and explain to me the problem with the hanging revs.
    1. he told me that the carbs has been checked yet again and were perfectly balanced.
    2. he told me that he had found the 'air screws' wrongly adjusted and asked who had last adjusted them, i told him 'YOU, two weeks ago'.
    3. he told me that it could be the valve clearances and suggested they had not been adjusted for a few years, i responded 'YOU adjusted them last year'.
    4. he told me that the hanging revs problem which appeared only after I had paid them to balance the carbs, only appeared because they now had the carbs balanced, and the problem was hidden before.
    5. now scratching his head, he told me that it could be the carb manifold, a leak in the pipes, and only further work, which would cost me more money, could cure the problem.

    They left me by telling me I had 'got off lightly' as 'you know, these old bikes, could have any manner of problem'.

    Finally I found Pete at Everything2Wheels, who took the beast, worked on it for three hours then called me to collect. He showed me printouts of the carbs as he found them, which were very clearly horrendously out of sync. He suggested that no qualified mechanic could have synced them once recently, let alone checked them three further times. He also noted that a bolt was missing from the airbox cover and there was oil in the carbs. He showed me then the printout of the carbs in line, and it sounded so much better, and of course, the revs were no longer hanging.

    Now Pete's tool for syncing the carbs also gave a read-out of the engine. I cannot recall the specifics (I was too happy just to have the carbs so perfect and the bike sounding happy at idle). He may have mentioned leakage or compression, but the general gist was that the bars shooting up on his gadget as the engine roared were ideally supposed to remain green, yet for my bike, they were shooting into the red all over the place. Which was bad news. he explained that the engine was less than perfect, and the work to rectify the issue was probably worth more than the bike itself.

    I would appreciate anyone filling in the blanks here. What was he referring to? Perhaps the valves not closing fully?

    Asked if it meant the death knell of my beloved two wheeled steed, Pete explained NO, it would simply lose power over time, and he hates to give the bike back to a paying customer in less than perfect condition. What a huge difference to Gassit Motorcycles of Fairfield!

    Since then I have changed the battery (first time since purchase in 2010), performed the regular oil and filter change, kept the chain and rear sprocket clean. All was perfect until recently...

    A week back, the bike began my morning ride to work in the CBD sluggish and wretched, it seemed like a fuel blockage, the revs lurching, the engine appearing gasping for fuel. I rode it through the nastiness and within five minutes it was fine and dandy. I found the same problem on the trip home later that day. And the next day only in the morning. I thought the problem had vanished, but it returned two days later. Since then, I have made sure to use the choke when starting, let it run with half choke on idle for a minute or two, and it has been perfect.

    A friend I trust with his mechanical knowledge told me I should clean the 'bowls' and ideally, strip down the carbs and give them a good clean with carb cleaner. I have avoided this job as I am unsure if I can get to the carbs, let alone take them apart, clean them and put them back together!

    So now, I seek advice, from anyone kind enough to offer after ploughing through the word waves above.

    Whilst the carb problem seems gone, should I pay someone (perhaps BikeDock/Intyre which seems well thought of) to investigate?

    What was the issue with the engine, and syncing tool showing crazy red peaks which Pete tried to explain to me? Is this something I could get fixed? I would be fine to spend 1500-2000 to get the engine sorted, if it will breathe new life into a beast which I adore. Yet what is the problem there and how much could it cost to fix?

    Finally, I have been pondering for a while paying a mechanic, ideally Pete, to replace the front fork oil, which has never been changed since I bought the bike, and how long before that it was changed is unknown. Let us say, at least four years, probably closer to 6 or more. Would replacing the fork oil make a noticeable difference to the ride?

    Any advice would be very much appreciated. And all I can offer in return is STAY AWAY FROM GASSIT MOTORCYCLES IN FAIRFIELD! And my gratitude.
  2. Dunno, But love the eloquence.
  3. dunno about the work itself, but if your after great mechanics depending on where you are 60 Degrees or Mad Biker
  4. My den is in Seddon, Mr Grey and Jeffco. It seems that Intyre could be the finest choice for me to sample. Easy enough to pop the beast there during my lunch-hour and collect after work, since I work in the CBD. Cheers for reaching the finish line on my wordy epic! And I wonder, is there a forum for warning other riders about cowboy grease-merchants?

    No idea of the engine issue Pete was explaining to me earlier this year? Leakage? Compression? Red bars on what reminded me of an old graphic equalizer on a stereo?
  5. I won't claim to know about the diagnostic method he used, but the loss of power over time (and graphs) kind of points to a cylinder compression test to me (happy to be corrected).
    Compression leaks can be caused by wear of piston rings and/or bore (the cylinder walls (big, expensive job), wear of the valves and valve seats in the cylinder head (still a biggish job, but not quite as exxy) or possibly a leaking head gasket, which Pete would have instantly identified so you can rule that out.
    Any good mechanic should be able to make an educated guess as to what it is but there is always the possibility that it ALL needs replacing.
    Your fuelling issue may or may not be related. Bit of water in the tank?
    Perhaps you can go as far as pulling out the spark plugs and seeing what shape they are in?
  6.  Top
    • Winner Winner x 1
  7. I'm not sure what "red zones" were being referred too, but it could be compression. If so, then so long as it's not a sudden loss of compression in one cylinder, then you could probably continue to ride the bike into the ground.

    The other aspects seems to be aging carbies. as they age you will cycle through cleaning, fiddling and syncing, but it eventually gets to the point where the bike is never right.

    15 years is a long time in the modern motoring world. Although you haven't mentioned the ks

    So I'm guessing the carbies are due to have a kit put through them. These carbie kits usually cost $50-150 per carbie and typically replace all the key components. I'd be checking to see if the needle jet is included in those kits and seeking advice if it isn't.

    Just checked online and a quick check suggest that carbie kits may be at the cheaper end of that scale for your bike, but don't include the needle jet.
  8. When Pete did some work on the Yam some years back he provided a graph to show the carb syncs. Sounds to me like that may have been what he was showing you. Although not sure what the issue would be with them which would cost more than the bike is worth.

    Stripping down carbs and cleaning them is not that difficult if that is what the issue is and plenty of YouTube vids to show how. Getting them off the bike to do that is perhaps a tad more difficult, especially if you lack fundamental mechanical skills. Perhaps your mate who advised on this can assist.

    Our resident Netrider mechanic @streetmaster@streetmaster as Rob suggested is competent and reasonable but is located in Frankston. Worth the effort if that isn't too far. However if you drop him a Message he may be able to give the bike a quick look over at St Kilda Saturday Practice.

    At this stage you haven't given enough info to do more than guess at your problem. But If the problem comes and goes, it could be a fuel blockage related. A change of fuel filter and a quarter cup of metho in the tank would not hurt and could assist.
  9. E2W was my Mecha when I had a Jap bike. Pete is a Mage.

    Good Bloke too. Likes good Metal and good Booze.
  10. Those digital vacuum gauges are very clever, and can analyse the timing of each pulse, to the extent where they can tell you if the valve clearances are out on a particular cylinder. It sounds like it might also be able to detect if a valve is leaking as well. If so, then engine top end may need refreshing. But if it is starting fine, not burning excessive oil, and will generally run ok, then you could perhaps not worry about it.
  11. GREYBM - I saw those pictures, took a copy actually as I still aim to run the Gassit debacle past Consumer Affairs, since I paid them for a job they suggested I had done, then I took the bike back three times and they lied by telling me it was perfectly synced, then I had to pay Pete to sync them.

    Digital vacuum gauges seem to ring some bells. The 'graphic equalizer' was analysing pulses.

    I had the valve clearances adjusted the year before by the exact same mechanic at Gassit who fcuked my carbs up then had no idea how to fix them so told me they were fine, over and over again. Now that he has proven himself incompetent and a liar, it follows that his 'work' on my valves the year before could well have been equally sloppy, if he even looked at them. Certainly charged me enough notes for whatever he did...yet I felt now major difference in the ride or engine after. Would I have felt a difference? With several shims replaced and valves adjusted?

    Pretty much what Pete said...if I am happy with how it is, there is no problem riding it.

    It starts fine everytime. Whatever the issue was with the fuel delivery a week ago, it has not reoccurred since. A week with no problems whatsoever. Perhaps it was some bad fuel or water in the tank or something else that can cause a problem for a day or three then vanish?

    it is old, looks haggard, the rear tyre has a couple of pieces of metal lodged in its rubber, and is plugged, yet loses pressure less quickly than the front. the suspension is probably long dead, yet I still absolutely love the beast. Its acceleration is demonic. Of course healthier, more modern bikes would be better, yet 0-100kmh seems 3 seconds or less, the power delivery remains always exciting, and its agility amazes me.

    There are 67000km on the clock. I was pondering paying Pete to change the front fork oil as I was told this would make a very noticeable improvement to the handling, if it hadn't been changed for at least 4 years, maybe longer...???

    I guess I am in position to spend some money on the bike. If I can invest a thousand or even two, and extend the life of the engine and improve the ride, I would happily do so.
    Considering I use the beast every day and love it!

    Perhaps it is best to simply keep riding. Although I was peeking at carb kits yesterday! Could a stage 1 kit make a decent difference? Or if the valves are a bit fcuked, would it be worth me paying to have them fixed? What kind of costs could be involved?
  12. You generally would not notice any change in the running when valves are adjusted, except if they were way out. But they usually do not wear much on an R6, even with high k's.
    Changing fork oil is a good idea. But can't say whether it would have a noticeable improvement in handling.
    Carb kit may only help if it has been modified with pipe & air filter.
    Does not sound like the engine is too bad. Best to spend your money on keeping it properly serviced. Eg oil, brakes, tyres, chain etc.
  13. I notice an improvement changing my oil every year. So 4 years will definitely be noticeable.

    Carb kits are not for improved performance, but rather bringing it back to where it was originally.

    Aftermarket Jet kits are for performance. You don't need that,
  14. Sorry for not correcting terminology ibast, but when he mentioned 'stage 1 kit' I assumed by saying carb kit, he was meaning jet kit. You are right though.