KymcoForum.com
Motorcycles => Venox 250 => Topic started by: kpolykarpou on April 30, 2012, 08:03:08 PM
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hi guys
need help again please
last wednesday, i noticed my oil was little down. so i brought my venox for an oil change.
notice that i also filled it with petrol , the same morning.
when i took it, the machine wasn t ok.
if i travel , in any gear, with half speed that it can go, it s ok . if i try to raise speed, it s reacting like the choke is on, or its not going petrol on the machine, with also sounds of shootings.
i tried everything.
cleaned the carbyrator, change air filter, check valves, changed sparks, . .....
also, i empty all the fuel and replaced it.
nothing
still the same.
any help?
any clue please???????
i love my venox.
but i m really fed up with problems lately, that i m seriously thinking to trade it up
thanks .....
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check compression. and recheck that the main jet needle is not damaged, whats the state of the plug when you try to push it over half speed. are both plug looking the same? shooting are you talking about pre-ignition bang? how low oil was it? there might be engine damage.
check engine compression 1st. you might have a ring problem when the oil was low. lets hope so.
engine low on oil is a dangerous thing. and maybe the choke is on... but that stuff is pretty solid, and if it were out you would have fouled plugs already. good luck and let us know if you find anything.
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how do i chech the compression?
what is the main jet needle?
yes it is bang-bang
i m sorry. i know them with greek definitions.
ring problem where?
you mean on the pistons?
sorry
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to check compression you will need to remove the side plates and screw an compressor meter onto where the spark plugs go. dont know how bad it is until you check the compression, possible just need new rings. but you should 1st try and find out where the oil went. anyways bang bang can sometimes mean too rich. when was the last time you changed air filter?
anyways 1st check compression if its good have a look on the plugs are they black and wet, if black and wet you will need to get a new air filter and adjust the idle mixture screw.
if the compression is bad or different, then check the valve gaps and if the valve gaps are ok then you have piston ring problem.
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its ok dont worry about the main jet needle, because as you said the problem happen after the oil change and the carburator was not touched. another possible is that the fuel tap valve on the gas tank is not working and you are not getting enough gas, but from what it sounds like you are getting more gas then you need. so check the plugs, if they are black and wet, but the setting on the carb. was ok which is around 1-3/4 to 1-1/2 out then you have a bad air filter. if plugs are looking white then the problem might be valves or piston rings. good luck. will be here if you need anything.
before we can say what is wrong and how to fix it you have to get the plugs out and have a look.
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so
what u mean plugs? is it the spak plugs?
as for sparks, they are new
air filter brand new
also, lately, i had a ""very good"" mechanic and he told me that my tank had diesel instead of petrol.
and for that, he chanced me 1 piston , cylinder, the rings, 3 eccentric , i dont know in english that,
and he ecpected me to believe all that.
ao, i guess the rings are new , filter too, sparks too, . filter and sparks 100% sure.
to check compression you will need to remove the side plates and screw an compressor meter onto where the spark plugs go. dont know how bad it is until you check the compression, possible just need new rings. but you should 1st try and find out where the oil went. anyways bang bang can sometimes mean too rich. when was the last time you changed air filter?
anyways 1st check compression if its good have a look on the plugs are they black and wet, if black and wet you will need to get a new air filter and adjust the idle mixture screw.
if the compression is bad or different, then check the valve gaps and if the valve gaps are ok then you have piston ring problem.
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hmmm then i guess there is only the compression left and valve gap. can you have a look at the spark plugs and see what color they are? here is a link for comparison. http://4.bp.blogspot.com/-j0zzs4Ml8NE/TgNu2KPVUAI/AAAAAAAACt8/Z--jY0NwoDs/s1600/Spark+Plug+Reading.jpg (http://4.bp.blogspot.com/-j0zzs4Ml8NE/TgNu2KPVUAI/AAAAAAAACt8/Z--jY0NwoDs/s1600/Spark+Plug+Reading.jpg)
there are many other pictures on google that you can look up and compare your plug color and diagnose the state of your jetting. about the diesel i have no clue, dont know if even the engine will run on diesel, some times i have heard people getting water in the gas by rain or gas station adding water... and if the bike has new rings there might be an earlier problem... if the cylinders were also damaged then with only new rings will still have problems.
check color of the spark plugs to see if its a setting problem and then if setting does not help, then check compression and valve gap. all the best buddy!
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thanks o lot guys
i found it at last
it was the timing the chain of timing
it was 2 teeth wrong.
imagine how good was my previous mechanic
thanks.
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congrats! hope everything are fine now! that kind of mistake is big. could have crashed the valves and piston head...
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guys.............. im desperate
it happened again
my mechanic said the tooth must be moved again,
how this can happen?
the chain was ok
maybe the .......wheel how is called inside the machine ??
i don t know what to do more with it
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Either your crank shaft gear is stripped, or your tensioner is bad. There is Supposed to be a spring loaded device that applies tension to the chain preventing your problem. Check your oil for metal pieces.
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check the auto tension it might not be working or jammed.
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auto tension?
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::)
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yes its one on each cylinder. sometimes it might be jammed and need to be losen.remove the cap bolt and use a screw driver to turn it out, you will feel the spring tention, dont turn it all the way out, just a little and see if it goes back and deeper then before.
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I think its the tensioner. I will change it and chain of timing. We ll see
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so how did it go buddy? did you sort out the problem?
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No. Still not working
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It might be cdi faulty. But low oil could have done damage already, have you checked your compressionyet? There is another way for diagnoses, hook it up to vacuume gauge and have a experienced tuner have a look at it, theses people can spot ring damage and seal damage valve damage just by looking at those dials.
And in the same time tune and balance the carbs.
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Somebody. Checked my compression and said is lower in one side
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Trying to upload video
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https://www.youtube.com/watch?v=XHQSn-MHgCc&feature=youtube_gdata_player (https://www.youtube.com/watch?v=XHQSn-MHgCc&feature=youtube_gdata_player)
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dude you got to slow down a bit, got dizzy after watching the video.
try twisting the throttle when starting, and just wanted to ask quick is your vacuum hose connected to the fuel valve? it feels like its not getting any ignition at all.
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Normally it was making also a krk krrk noise
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I did that with throttle . no result
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try to drain the bowls and see if fuel comes out of them. maybe your fuel valve is not working, are the sparks wet or dry?
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https://www.youtube.com/watch?v=XHQSn-MHgCc&feature=youtube_gdata_player (https://www.youtube.com/watch?v=XHQSn-MHgCc&feature=youtube_gdata_player)
Take your carburettor off from the inlet manifold/motor.
recharge your battery.
Press the starter button to crank over the motor.
Let the motor turn over 4 or 5 times and then start to spray little squirts of cold start engine start spray.
Tell us if you had some combustion noises!