green250 Posted May 6, 2011 Posted May 6, 2011 can someone help me out? it's an XS250, with electronic ignition - the timing seemed alright, marks lined up, went alright for a while, then later on started a bit of backfiring - pretty sure carbs are ok, and no air or exhaust leaks - checked the timing, and on the left side it seems to be way advanced(? - the double line marks for full advance are about 10mm to the right of the pointer). so i adjusted the points plate to get the left side marks to line up, but now the points plate is in a totally different position (anti-clockwise about 10mm) - then checked the right and it was out the same as the other was. tried to get that to line up, but because the points plate has now shifted, i can't get the right side to line up. sorry if this is an obvious one - i'm definately a learner. just want to know whats going on, as it was alright before - what causes the timing to go out? is it valves? cam chain? the electronic ignition components? i understand that i've probably screwed up my timing even more by altering it if there is something else going on. anyway, any help would be appreciated - i would rather TRY to fix it myself, as i don't want to spend much time or money on a motor which, at it's best, was nothing fantastic - i would rather wait and look for maybe a 400 to put in it. by the way, i read a couple of posts about putting a bigger motor in the 250 frame - what about the 650? or is that too big to fit? someone mentioned the XSV250, but there was no answer - does anyone know about that one? and i'm also wondering, what about other motors from anything as long as the dimensions are close? maybe with some alteration of the mounts? thanks.
Moderator drewpy Posted May 6, 2011 Moderator Posted May 6, 2011 I would look at your battery. if its even the slightest way down, it will affect the ignition. the electronic ignitions need a healthy (ie good amps) battery and the battery is also used for charging! (sounds odd but true)
green250 Posted May 9, 2011 Author Posted May 9, 2011 I would look at your battery. if its even the slightest way down, it will affect the ignition. the electronic ignitions need a healthy (ie good amps) battery and the battery is also used for charging! (sounds odd but true) Any other ideas? got a new battery (good one), fully charged - but the timing is still way out as described above - i can get the left side marks to line up, but still runs rough, and when i try to line up the right side it gets even worse. as i said before, it was going all right before - the marks used to line up, now it seems to have shifted to an advanced postion by about 10mm. what about the other things i mentioned? i'm thinking it might be something else. thanks.
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