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CBR125R Oil problem, loud tapping, squeaking engine

Discussion in 'Technical and Troubleshooting Torque' started by Donmotorcyclemaniac, Jul 4, 2016.

  1. Got a few problems with this one. CBR125R 2007 (fuel injected), 27,500 km.

    In order of occurrence.

    1) When cruising on the highway the engine stopped running smoothly and began loosing and gaining engine power as if I was rapidly turning the throttle back and forth. This made for a wild ride but was less terrifying at lower rpm and 80km per hour.

    2) Instead of starting the motor immediately there is a 2 second pause before the starter motor begins cranking the motor, it takes the right amount of throttle to eventually get the motor to idle.

    3) The motor started clicking loudly when cranking the motor and at at idle.

    4) The motor started screeching like a bird in a blender when starting the engine..

    5) The engine has spit out oil two feet to the side of the bike on one occasion when starting the engine.

    6) When filling the oil (it was almost empty), I stripped the sump thread turning it the wrong way.

    7) After reving the engine I can hear a sandy sound in the motor when the rpm drops. Maybe something is loose in there.

    Despite the starting troubles the engine seems to work fine once it gets going around town with no noticeable loss of power except when the engine cuts out when I release the throttle sometimes.

    It looks like a big job and if it is too expensive I'll have to dump the bike and start walking. I thought I'd ask for some advice before I spend several hours and possibly thousands of dollars trying to get a munted engine to work. My last motorcycle was expensively munted.
  2. Sorry but it sounds like this one is munted as well. It sounds like it's been allowed to run with insufficient oil in the sump and something has torn up. Please, stop trying to run it until it's properly diagnosed and fixed!
    • Agree Agree x 6
  3. I'd be looking in the wreckers for an engine.
    • Agree Agree x 1
  4. No healthy engine should ever make that sound! Either try to find a second hand motor without sand inside or a new bike.
  5. Do you want the bad news or the worse news?
    Despite your optimism the bike is certainly not fine and their is a high probability the engine will spectacularly detonate in the next hundred k, personally I'd rather not have my crotch wrapped around it when it does, nor be going down the highway when the back wheel locks.

    Fit a new engine into it it, thankfully its only a 125 and follow a servicing routine.
  6. not good.
    get mechanic to put a borescope through the spark plug hole first, and see if you've munted the bore and piston.
    1. probably starting to seize from lack of oil
    2. getting up some puff before breaking stiction of stuffed rings and bearings
    3. flappy metal, not good
    4. release birds from blender, they don't make good meatshakes

    5. that's impressive, perhaps the bike was spitting at YOU? you don't seem to have a good relationship with it.

    really not a happy bike... if you're lucky, it's only the motor that is stuffed... probably time for a new bike
  7. Small Honda+no oil=buggered cam bearings, which means the cylinder head is likely to be a write off.
  8. I've done a bit of dismantling, I'll take the engine apart tomorrow and determine which parts appear to be damaged.
    2016-07-05 16.19.54.
    • Like Like x 1
  9. The cylinder looks fine to me. There is a little bit of damage to one of the gaskets pictured.

    I took off both sides of the engine (crank case and the other one) and those look fine.

    The oil plug nut can hold onto some of the thread so I can probably get away with a rubber washer to stop leaking.

    I'm going to put it together, put oil in it and see if it starts.

    Attached Files:

  10. #10 Zim, Jul 17, 2016
    Last edited: Jul 17, 2016
    Put some fuel in the head camber and see if it leaks past the valves. If you are going to keep the engine at least do a thread repair on the drain bolt. Timeinserts are best. Was there metal particles, shinny, in the oil when you drained it. If its been run with well low oil then the head,that does not hold cam bearing like said has probably been flogged out,the cam spins directly against the head and NEEDS oil
    It has a hell of a lot of expensive issues,sounds terminal, who knows.
  11. This is where I am up to, motorcycle back together with new battery but I have a loud click to sort out.

    Not much petrol in there as it has mostly evaporated.

    edit: I was going to let this motorcycle rot but I like it a bit more than my new motorcycle so I might put some more effort into getting it running, at least get it to the mechanic so they can give me a quote for fixing the engine problem.
  12. Can you spin the engine by hand?
    If so check the starter is connected properly, it sounds like the relay to it works.
    • Agree Agree x 1
  13. #13 cjvfr, Sep 3, 2016
    Last edited: Sep 3, 2016
    Yep starter solenoid closing from the sound but starter motor not turning. I notice the dash lights go out when you try and crank so check battery is fully charged and connection, the big wires, to the battery and starter are tight.

    But do as Nicholai says first check the engine does turn by hand. Maybe pull the spark plugs so there is no compression when trying to turn by hand. Ignition off by the way.
    • Agree Agree x 1
  14. C'mon Chris, don't baffle him with science ;-)
    • Funny Funny x 1
  15. I suspect that it's seized solid. The dash lights going out could denote a dying battery, but it's more likely the starter motor drawing everything the battery's got in trying to turn over a completely locked engine.
    • Like Like x 1
  16. That's my thinking as well or the timings off with a valve stuck against the piston.

    My second thought was the starter was shorting however the main fuse didn't blow or shower OP in sparks....leading me to think its disconnected.
    Normally with a flat battery that starter relay will tick however it certainly is a likely candidate if the battery has been sitting for a few months.
  17. That's a very loud and healthy clack from the solenoid for a dead battery.
    • Agree Agree x 1
  18. I bought the new battery that yesterday so it is new battery.

    Edit: Going to try turning the motor by hand today.
  19. I pushed the bike in first gear without any issue. I suspect three things could be wrong.

    the battery is
  20. Do you mean existentially? ;)

    As Pat said it sounds a healthy main solenoid closure so battery charge shouldn't be an issue especially as you say it is a new battery.

    Starter motor jammed?
    Stuffed brushes in starter motor? (Unlikely because of the drop in lights when attempting start)
    Jammed Starter clutch.
    • Informative Informative x 1