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Full acceleration bike just revs

Discussion in 'Technical and Troubleshooting Torque' at netrider.net.au started by RedWings01, Jun 27, 2016.

  1. So, today I noticed when I max out my throttle, it just revs up and the speed does not increase. It doesn't really happen in first or second but def happens in other gears. I tried riding at 30-40km/h and putting it in max gear and accelerating hard and it really just boggs. Also when you max throttle at 3rd gear and it revs up, you can hold it there for like 3 seconds and it just keeps revving. When I slowly back off the throttle, I feel a small jolt in power pulling me backwards. Almost like letting out the clutch too fast. I think this is clutch slippage but am not completely sure. Never really noticed this because I never accelerate that hard until i decided to try today. Also I noticed that If i turn the bike off, put the bike on a small uphill in gear then hold the clutch in, let it get to like 3-4kms a hour then slowly release the clutch, it has a small clunk clunk clunk like its not smooth. When taking off it does this enough to be noticeable but not a massive clunk clunk clunk. I feel that if I apply extra throttle and let the clutch slowly slip you cant really feel it.

    With my clutch cable adjustment, I have the correct freeplay at the lever but no freeplay at the engine casing. Is that the issue? I watched a video mentioning about that but nothing in my manual other than the freeplay at lever.

    Is it time for new clutch plates? Or is there some other possible issue causing this? If it is the clutch plates, do I only replace the fibre ones or the metal ones too? Maybe the oil? I changed the oil a few weeks back to a Penrite 10W-40 which said on the back "Able to be used in 4 stroke motorcycles" "Can be used in most Japanese bikes with a wet clutch" "No friction modifiers added". So i assume the oil wouldn't be causing the problem... but not exactly sure.

    Thanks for taking your time to read this. Any help is appreciated. If it is the clutch, I'll prob just do them myself as It seems very straight forward.
  2. Sounds to me like clutch slip,
    I'd try to adjust your clutch cable again, make sure your going the right way!

    You should replace the steel clutch plates at the same time, especially if they are only a few dollars more.
    Personally I don't bother on the first time its changed given I know it hasn't been abused or overheated which can warp, discolour or glaze the plates.
    Only other exception is bikes with long lead in times to get parts or in situations you don't want to pull the bike to peices again

    Assuming your using the Penrite everyday fully synthetic 10-40, that stuff is fine and won't affect a healthy clutch.
  3. Clutch is fcuked or out of adjustment of cable operated or your chain/sprockets are missing lol
  4. #4 the mole, Jun 28, 2016
    Last edited: Jun 28, 2016
    If wanting help from others, you need to make yourself easily understood, I have no idea what "putting it in max gear" means.
    It sounds like your clutch is slipping. It may be that the cable needs adjusting at the engine, you need to check the correct procedure for your bike. Do that first, then set the adjustment at the handlebar lever. Make sure you get that right before spending time/money on parts. Clutches are usually pretty bullet proof unless they've been abused.
  5. RedWings01RedWings01 have you got a workshop manual for your bike like a Haynes or Gregorys manual or something? The owner manual is fine for checking service schedule and checking what your chain slack should be but if you're trying to adjust cables and you're not entirely sure, you need a workshop manual... They're cheap (<$50 for a hard copy, <$10 for an electronic copy) and they take a lot of the guess work out...
  6. Clutch springs are worn heaps and has fcuked the friction plates as well I reckon.

    You can order a kit from ebay, super chinese special for under $100 AUD and cut out a gasket using a cheap paper folder from Kmart! Will take you about a night as you will need to soak the new friction plates in oil overnight and pop them in in the morning.

    I did this on my old i4 250 and it was so much better to ride!
  7. Not sure why you'd suggest that. Gaskets are relatively cheap from a dealer. I'd buy the proper part. I just can't fathom why people cheap out on proper parts.

    The amount of newbs who struggle to get a stripped sump bolt out and then put it back in astounds me when a bolt is usually in the $3-5 range and in stock at basically every dealer.
  8. Depending on the bike the dealer may not want anything to do with them. In my case I had a grey import and my dealer refused to even change a tyre.

    If it's easy for OP to get a gasket then get a proper one, otherwise... Improvise!
  9. And while the plates MAY be worn, it is worth doing a proper check of the adjustment first. It doesn't take much pressure on the pushrod if its adjusted too tight to cause slippage.
    • Like Like x 1
  10. I reccon motorcycle gaskets are an absolute rip off. Maybe on trailies where you have to rebuild them all the time, they are OK, but on most road bikes, they are a scam.

    Having said that, I'd still be 50:50 and if I didn't by the original gasket I wouldn't be useing paper, I've be using a liquid gasket. Many OEMs are using them throughout engines these days anyway.
    • Agree Agree x 1
  11. Having bought a proper gasket online and have it leak after a week sucks, especially since I only did the folder trick to get to the bikeshop to try and order a proper one.
    Turns out it held much stronger and never had a leak in the 9 months it was on there :p
  12. #12 the mole, Jun 28, 2016
    Last edited: Jun 28, 2016
    Need to be a bit careful replacing gaskets with a liquid product, as in some instances the gasket thickness ensures the right clearance between parts.

    I once bought a 250 Ducati cheaply because it was running a bit rough, turned out someone had used a silicone sealant instead of a base gasket and had used plenty of it to make sure it didn't leak. They were so successful that no oil 'leaked' up the gallery into the cylinder head, with disastrous consequences for the cams, rockers, bevel gears, bearings and my wallet. That was a long time ago and the start of a very steep learning curve!
  13. #13 RedWings01, Jun 28, 2016
    Last edited by a moderator: Jun 29, 2016
    Ok thanks for the replies. I have the workshop manual and have been reading about the clutch cable adjustment and I'm pretty sure I'm good. I have the perfect amount of free play at the lever. I rode again today and realised when I max throttle, the bike revs up almost to redline and sits there for a few seconds as the speed finally catches up. I'm almost certain I need new clutch plates.

    From reading the manual, I apparently adjust the clutch cable at the lever for minor and engine casing for major adjustment. This is exactly what I did. And not to mention I had my bike serviced a month ago so they def adjusted the cables.

    The clutch slip is not really noticeable until you really hammer the throttle. You can't really notice it when riding around the city.

    If I was to replace the clutch plates do I need any special tools. According to the workshop manual I need some special tools but from the videos I've watched, they don't use any special tools.

    Im probably just going to buy the OEM gasket just to save myself from screwing things up.
  14. You generally need whatever the workshop manual tells you that you need. Sometimes you can improvise, and a lot of people do to save money, but if the workshop manual calls for a certain tool to be used generally it's a very good idea to use that tool...
  15. For the most part you won't need special tools however it wouldn't hurt :p
  16. Just because your bike has had a service, don't assume anyone adjusted the clutch at the engine. Make sure that adjustment has been done correctly (there should be a little free play, if not it will slip) before committing to major work.
    Apparently some VTRs have a special 4 point ring nut, some a 27mm conventional nut on the clutch.
    VTR250.org • View topic - Clutch Change on VTR 250
  17. #17 RedWings01, Jun 28, 2016
    Last edited by a moderator: Jun 29, 2016
    Do I buy the tools from a honda dealer? I wouldn't mind buying the special tools just to make everything easier but I won't be spending a million dollars for some special tools I'm most likely not going to use again on this bike. If the tool cost anything between 30-50 I would be happy but not paying over 100 for them as I could just take my bike to the mechanic and have them do it for the cost of the labor.

    Anyways, I would like to do it myself and it seems pretty straightfoward. So what I need is spings, clutch plates (fibre and metal) and a new OEM gasket. Is that all? Or am I missing something?


    Okay, what I understand is that you adjust the free play on the lever and if you cant get the standard freeplay you adjust at the engine casing. Currently I have the standard free play at the lever but have not checked at the engine casing. I tried doing it a while back and I figured that tightening the adjuster on the lever actually tightens it at the engine casing. From what I assumed, the clutch lever adjustment and engine casing adjustment work exactly the same except one is for minor adjustment and one is for major adjustment. So If I have the freeplay in the lever, I should have the same free play in the engine casing.

    Also the manual does not specify anything about the engine casing except that major adjustment needs to be done there. The only specifications it has is that there needs to be a certain freeplay at the lever.

    Thanks. If I got anything wrong please correct me as I am new to all this and just learning from my research online.
  18. You could probably order the part online, I think it's just a 27mm socket but i;m not 100% sure sorry mate
  19. Ok I think it is a 27mm socket too. I just check the manual and the part number is 07716-0020300 if you google it, you can see. It looks like a normal socket to me.
  20. Vtr250? Some lesser powered bikes/poorly tuned bikes will bog if wack the throttle at low engine speeds. Random oscillations in acceleration/power at specific rpm can be caused by poor/stock/wrong carb jetting too.

    Sounds like it might be fine adjust the clutch and see if you get used to it.