Superpro Posted October 12, 2012 Posted October 12, 2012 Recently purchased a xvs 125 in ok condition,but she has just given me problems.The bike will not rev,it bogs down on acceleration, I have to use the choke to get any performance out of this motor? The only non standard part on this bike is the air filter and I'm thinking this is the cause of this problem. The intake manifold is not cracked and its not leaking air,the carb is clean and some days I can get the motor to run trough the rev range in 3 gears then have to back off cause of the speed. A yamaha mechanic has looked at the motor and he is saying the rear cylinder is low on compression and this is the reason the bike needs the extra (fuel) choke to run? Any ideas ? The bike has also blown the rectifier ,starter solenoid and melted the battery. I have replaced all these items and shes still not reving? Any ideas?
Moderator Airhead Posted October 12, 2012 Moderator Posted October 12, 2012 If the yamaha mechanic says the rear cylinder is low on compression, then thats the thing to remedy first isnt it? how long have you been riding this bike has it ever performed well when did it stop performing well was it a sudden change you want help...try and give as much detail as possible...always! aside from that...needing choke in order to 'rev' the engine could be an indication of a blocked main jet in the carb so it's worth checking that one out
Superpro Posted October 12, 2012 Author Posted October 12, 2012 Hi I have just bought the bike, maybe done 100 miles ,have just used it to work and back . I was told it has stood for 3 years . Its getting better the more i ride the bike and its got enough power once the the revs are up ,its also more responsive when the motor is hot. Going to check the carb again like you said. Thanks
Ttaskmaster Posted October 12, 2012 Posted October 12, 2012 3 years? Top down service. First thing. Check, adjust and clean everything. Full-on project, just to be sure and eliminate as many common issues as possible for as little money as possible!
Superpro Posted October 15, 2012 Author Posted October 15, 2012 Well just an update, I checked the jets and they where all clean.With the carb back together the engine was still the same.I then open the pancake air filter and choked the air intake with my hand while reving the motor and it reved freely. So I restricted the air flow with a strip of gaffa tape block off the the breather pipe hole on the air filter and the she is going great. For a 125 that is. Done 25km and the motor is responding well through the complete rev range and through all the gears. Got a grinding sound in 1 st 2nd and 3rd gears but the higher you go in the gears the less the noise?? Any body got a workshop manual for this motor?
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