Just bought a Yamaha YZ125 '00 model and I am sure that the ignition timing is heavily moded by the previous owner. Bike does not perform at all at low RPM and goes like a top at high, meaning that ignition is probably retarted quite a long way! Can anyone explain to me how to make sure I set it back to the factory default setting? Any help or replies would be much appreciated.
If I remember correctly their are two lines that you line up. Remove the cover and their are three phillips screws you loosen to align the marks. I will double check this in my manual for you and post again shortly.
I reviewed the manual and it states that if the marks are aligned then it should be set correct to the factory specs. Have you removed the left side cover and check to see if the marks are aligned? It should be two lines, I believe one is on the case and the other is on the top portion of the stator (at about the 12 o'clock position).
Originally posted by antonyp Just bought a Yamaha YZ125 '00 model and I am sure that the ignition timing is heavily moded by the previous owner. Bike does not perform at all at low RPM and goes like a top at high, meaning that ignition is probably retarted quite a long way!
You know Rich, you MAY have hit it on the head, that's a good one... Unless you know FOR SURE the guy modded the ignition, maybe he didn't, many people look other places for mods first, or he would tell you how he changed things. The powervalve is a very possible cause of this... Let us know what you find.
I check the power valve and i works just fine i moved the ignition timing but still the bike has a dead low mid power incontrast when it revs up high goes pretty well.
Having had the 2000 model and then '02 and '03, I remember that the '00 model had a problem with fuel starvation. The float level was very sensitive and the only mod was to add extra breather pipes. Also, check and see if the exhaust port height has been altered. And then, check whether cdi is stock.
Regards
Anton