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Aprilia RS 125 smoke issue

Discussion in 'Technical and Troubleshooting Torque' at netrider.net.au started by speedy300zx, Jan 26, 2012.

  1. Hi there guys,

    I ride an Aprilia RS 125 2007, recently I had the top end rebuild on it, b4 the top end rebuild, it was running like an old lady, lots of flat spots, wudnt wanna go above 60km/hr, almost no power in 4-5-6th gear, so yeah the top end's been rebuilt, & now after the top end I m facing many issues with it.
    1. Smoking heavily constantly.
    2. loosing gear oil, I believe its burning gear oil.
    3. Everythin else is working on the Odo except the KMS.. its stuck @ 34598 as a matter of fact ideally it should have approx 26000km on it but I dont know where the 34598 came from.
    4. Flat spots under 7000 rpm.

    I know it a bad sign, but I need to be directed to the right direction, as I believe every mechanic out there is saying different things...I really dont wanna get rid of the bike...

    Thanks in advance..


  2. most likely bottom end gone
    • Like Like x 1
  3. Who did the work ?
    Was it losing gear oil before the rebuild ?
    Were they supposed to fix everything, or just rebuild the top end ?
  4. what colour is the smoke? What 2T oil are you running?

    If the big end goes, it would have made a lot of noise or caused a terrible seizure.If you're thining the gear oil has gotten into the engine, then a bearing and/or seal has let go, so someone hasn't rebuilt it properly or there is damage there.

    When was the last time you cleaned the RAVE (power valve)?

    What fuel are you running, what does your plug look like? What mods have been done to the bike?

    The more info, the better it is to help you along the way.
    • Like Like x 1
  5. If gear oil is disappearing and there's no leaks...suspect a crank seal...usually means that the crank bearing are on the way out....when did you last do a 'bottom end rebuild'...crankshaft, bearings and seals have a defined service life ( 30,000kms )

    This may be of interest....https://netrider.net.au/forums/showthread.php?t=112983#.TyHi_PnYjQM
    • Like Like x 1
  6. Agree with Mike. Losing gearbox oil combined with smoke means your crank seals have gone. Get it fixed or you'll lunch your gearbox fairly quickly. Drinking gear oil won't do your engine any favours either.
    • Like Like x 1
  7. Clubman motors did da work on top end.
    It just started to smoke very little b4 the top end & was losing power so I was been advised to do the top end.. But everythin else started after the Top end rebuilt.
    i rekon they didnt even notice the crank shaft...

  8. The smoke is white in colour, I have always been running MOTUL 800 in it,, Power valve been cleaned the time of rebuilt,, Always been using premium..
    The bike itself still has lots of power, but when it gives me flat spots under 7000rpms, this results in lack of power, but once hit the power band, its going good except the smoking issue..
    by looking at teh plug, itss running a little rich & till now no Mods been done to the bike.. its stock RS 125..
    I am taking it to the mechanic tomorrow,, I rekon as all of you have suggested, it cud be crank seals.. Lets c what the mechanic says.

    Thanks a lot
  9. hi i've got the same problem on my RS125 but its been like that since i've bought it. There is no exhaust manifold so the bike smokes from under the engine and from the exhaust but anyway.

    Theres a lot of white smoke even if the engine is warmed up. Could it be sorted with adjusting the oil pump?

    to thread starter - please let me know if you have sorted the problem out. Thanks
  10. I haven't figured it out, but I had to drop the fuel to 91RON on my RS125. Before I ran 95RON and it kept fouling out and I had to change plugs every 1500km.

    Before the plugs gave up I would lose power drastically then one day... gone.

    I've been running 91 fuel for a few months now and no issues?!?! Go figure.
  11. Are you riding the bike the way it is meant to be ridden? Or is it a commuter?