Any body no whats wrong with my yamaha aerox!

Discussion in 'The Workshop' started by 50cc-of-Sex, Jan 15, 2008.

  1. 50cc-of-Sex

    50cc-of-Sex New Member

    Messages:
    6
    my yamaha aerox wont start i was told it was the spark plug so i changed the spark plug and theres abit more life to it but it just keeps cutting out anyone no what could be the problem?
     
  2. Nitro-Rhys

    Nitro-Rhys Active Member

    Messages:
    1,397
    what mods u got on it?
     
  3. 50cc-of-Sex

    50cc-of-Sex New Member

    Messages:
    6
    Mods

    i have a power pipe and racing rollers i took the exhaust off it there to clean it up i started it with it off and it started but cut out now i have it back on and it dont start atall.
     
  4. Dec

    Dec Active Member

    Messages:
    3,183
    Rides:
    nothing ugm
    ht lead??
     
  5. Jamie

    Jamie Active Member

    Messages:
    5,370
    Rides:
    xt660x, 200sx s14a
    check the whole thing for air leaks, reedblock, manifold, crank seals, check that you have sufficient compression, and that fuel is getting to the carb.

    also check the vaccum pipe that goes into the crank case cuz if this falls out it will have a hard time starting
     
  6. spectroplasm

    spectroplasm Member

    Messages:
    68
    Rides:
    pug309 GTI / PGO bmx
    Re: Mods

    ok mate let's get you sorted out :)

    first of all i'd like to ask you some questions on your bike.

    1. how long has this problem persisted?
    2. when you last rode your bike did you notice anything like
    - a dry sound coming from the engine.
    - the bike hesitates to accelerate
    - smell of iron (high heat odor coming from your exhaust as if it overheated)
    3. did the bike start for 3 seconds then cut out?

    here is are some things on to why your bike is doing that

    1. when you tried to turn on your bike and it wouldn't start, your spark plug got wet from the fuel mix, this is why when you have switched with a new spark it got a little life, because the new spark was dry and the spark reduced from the fuel mix.

    2. your bike has very low compression, when you took of your pipe there was no return force so the bike had a faster chance of combustion expulsion out the exhaust port. When you assembled the pipe the power pipe returns the unburnt ari back into the barrel yet the barrel doesn't have enough compression to build up power, you can hear this when you start the bike and it seems to roll in place but as soon as you let go of the starter or kick it dies.

    3. to know if it's your spark that is faulty take it out plug the spark wire to the loose spark plug and put the spark head against your frame, next have someone push the starter or kick your kick starter, check the spark plug it should emit a nice blueish white spark after each complete crank revolution (each turn). if it emits this your spark is in good condition.

    4. quickly check your compression with you finger put to the spark plug hole. plug your finger there and push firmly not to let any air out (remember thickest finger that will fit not pinky ;) ). Again have someone push the starter or kick the kick then check the following:

    a) if your finger flies out of the hole your compression is good, check you reeds to see if they have dabs of sand on them or they are worn out, check you carb clean if necessary, verify the settings to make sure you don't have too much gas running out of it.

    b) if your finger stays there but the pressure nudges it in and out, check all around the neck of the barrel and the cap for any possible leaks if there is then tighten your bolts and retry step 4, if there is no leaks you need new rings.
    Slowly unmount your engine and take off your barrel, slide it out with one smooth pull if you nudge it left and right as you pull it it will have micro dents which is not good as this will later on lead to compression leaks.
    Once the barrel is taken off inspect the inner walls for any smears or scratches. If you have scratches then something went wrong. clean you barrel with petrol and make sure you hone it just a bit so your new rings and or piston will have an easier task of adapting them selves to your barrel.
    Check you piston, is it all clean? (the detonation only makes the top of your piston black or deep brown, it shouldn't be seen along you piston walls, if you do have brownish marks on your piston sides which are called heat streaks this means you rings aren't doing their job, take off you rings and check them, look for uneven use (some parts of your rings will be thinner this is due to piston rattle coming from bad bearings or a faulty crank rod).

    c) if your finger doesn't feel anything or a very feint nudge follow steps b)

    after you have installed the new piston/rings and put everything back together, put a teaspoonful mix of motor oil and gas in the spark plug hole in and install you spark re-install you pipe and water pump (if you are in LC setup). during the kickstart/starter process of your bike, to help you start her up quicker take of your air filter and plug the air admission of the carb this will rush the gas and existing air into engine and boost the chances of a quicker start. Once the bike start remove your hand from the carb and let her start and idle for 15seconds or more. after kill the engine. re-install your air filter. and start her up again, she should be able to start all by herself now, let idle for a minute.

    once that is done it's break in phase:

    phase 1
    - start engine
    - let idle for 30 seconds
    - throttle the bike two to three times (removes bad smokey gas mix)
    - let idle for 30 seconds
    - ride bike for 1 kilometer at no higher than a quarter of it's throttle 25% (alternate the throttle don't ride at constant speed your engine will adapt to it and it's not good)..
    - park bike let idle for 30 seconds
    - throttle two to three times
    - kill engine let cool for 30 minutes

    phase 2
    - start engine
    - let idle for 30 seconds
    - throttle the bike two to three times (removes bad smokey gas mix)
    - let idle for 30 seconds
    - ride bike for 2 kilometers at no higher than a half of it's throttle 50% (alternate the throttle don't ride at constant speed your engine will adapt to it and it's not good).
    - park bike let idle for 30 seconds
    - throttle two to three times
    - kill engine let cool for 30 minutes

    phase 3
    - start engine
    - let idle for 30 seconds
    - throttle the bike two to three times (removes bad smokey gas mix)
    - let idle for 30 seconds
    - ride bike for 3 kilometers at no higher than a quarter to it's full throttle 75% (alternate the throttle don't ride at constant speed your engine will adapt to it and it's not good).
    - park bike let idle for 30 seconds
    - throttle two to three times
    - kill engine let cool for 30 minutes

    Phase 4
    - start engine
    - let idle for 30 seconds
    - throttle bike two to three times
    - let idle for 30 seconds
    - sprint the bike for 100 meters at full throttle (pump it half way then let go and pump to full throttle), this will blow out the sanded piston dust and ring dust out your pipe.
    - park bike and throttle two to three times.
    - let idle for 30 seconds
    - kill engine and let cool for 45 minutes

    phase 5
    - repeat phases 1 to 4

    you're done :)
    re-inspect carb settings, spark plug water level (if you are on LC setup)
    the above steps is the proper way to break in any new bike regardless if you got it new or just switched parts, the 500kmh limit line that the manufacturer tell you is practically the same thing if you compare with the above steps, only difference is you are doing it gradually instead of the everyday use. :) and NO CRAP OIL please it's not true what they tell you, crap oil only gives you debri in the exhaust port and will foul your plug quicker, not to mention the crap oil excrements will dirt up your silencer's wool.

    :) happy riding mate, lemme know if you still have probs with the bike
     

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