yzf400 Posted April 5, 2009 Share Posted April 5, 2009 Ok so i have taken apart and rebuilt the head on my yz, i am now familiar with the engine! I bought the bike as a non runner, The guy said it was working 1 week ago and then suddenly died, it will kick over and fire for a few seconds but thats it, When i had it apart i checked the big ends and from what has been said on this forum they SEEM ok, My next step is to change piston and rings and gaskets for new. Am i doing the right thing here? or is there some thing else i should be doing??? Regards James Link to comment Share on other sites More sharing options...
JimR Posted April 5, 2009 Share Posted April 5, 2009 Ok so i have taken apart and rebuilt the head on my yz, i am now familiar with the engine! I bought the bike as a non runner, The guy said it was working 1 week ago and then suddenly died, it will kick over and fire for a few seconds but thats it, When i had it apart i checked the big ends and from what has been said on this forum they SEEM ok, My next step is to change piston and rings and gaskets for new. Am i doing the right thing here? or is there some thing else i should be doing??? Regards James Hi James, it would appear you have over complexed the issue, if the bike tried to run, it would be good practice to check the ignition and carb out b4 pulling the motor to bits. before spending money on rings, carefully remove them from the piston and check the end gap, while they are off the piston you could also check the piston to bore clearence, if this is ok you can deem the motor to be ok and then go to the carb & ign .. I am asuming the bike is a YZ motorx bike and not a YZF road bike... if so please disregard this post. Regards Jim Link to comment Share on other sites More sharing options...
yzf400 Posted April 5, 2009 Author Share Posted April 5, 2009 yes it is a moto x bike, Thanks for your info, i am new to four stroke bikes! I just find it strange why some one sell it so cheap if its a simple carp problem, The guy said he was riding it last week and it suddenly died, he reckons it was blown up!!! the barrel seems all in good condition and so did the rings, saying that im not sure if i could tell the difference between good and bad rings! What sort of carb things should i be looking at, The engine fires for about 2-3 seconds then dies no matter what throttle you give it, It also take a realli long time kicking before it will fire, But it does fire quicker if i blow down the fuel tank and force fuel throught! Not sure what to do next now lol Regards James Link to comment Share on other sites More sharing options...
Moderator Airhead Posted April 5, 2009 Moderator Share Posted April 5, 2009 tell us about the fuel tap, does it have ON, OFF, PRIME positions? is there two tubes, one for fuel and one for vacuum to the intake manifold? Link to comment Share on other sites More sharing options...
yzf400 Posted April 5, 2009 Author Share Posted April 5, 2009 tell us about the fuel tap, does it have ON, OFF, PRIME positions? is there two tubes, one for fuel and one for vacuum to the intake manifold? I cudnt tell you without looking and its jus got pitch black outside, whats your reason for asking? Regards James Link to comment Share on other sites More sharing options...
Moderator Airhead Posted April 5, 2009 Moderator Share Posted April 5, 2009 I cudnt tell you without looking and its jus got pitch black outside, whats your reason for asking? Well you implied that it nearly ran when you blew pressure into the tank , But it does fire quicker if i blow down the fuel tank and force fuel throught! tell us about the fuel tap, does it have ON, OFF, PRIME positions? is there two tubes, one for fuel and one for vacuum to the intake manifold? So i'm thinking we should investigate the possibility that the carb is not full of fuel as it should be. Link to comment Share on other sites More sharing options...
yzf400 Posted April 5, 2009 Author Share Posted April 5, 2009 ah right i c, soz Erm there is def fuel getting to the carb as for thru the carb i have no idea, I just find it hard to believe that could be the problem when the guy said he blew it up lol, but from what you guys say i could be the case Link to comment Share on other sites More sharing options...
Recommended Posts