20 Most Recent 2003 Yamaha YZ 125 - Page 8 Questions & Answers

I'm sure you fixed the problem by now but I just read it.The on/off nozzle is called a petcock, turning the gas on when the engine runs and off when it stops.There is an after market gasket replacement kit available,Check them out on line or at a local dealer/

Can I get a “very helpful” rating on this answer? Thanks!

TRANS HAS A WORN GEAR THAT IS WEARING UPON 2ND SHIFT

Your mid and or hi speed jets are plugged. Drain the fuel (tank and carb). Dissmantle the carb, remove the jets and clean them. (Or soak the in carb cleaner over night).

Fuel turns to varnish in just a few months.

good luck

Several things could cause this and are somewhat inter related. I would clean the carb inside and out to start with. Check the reeds for cracks, chips and distortion. The cost is only a can of spray carb cleaner. Timing is not likely to be a factor. Use a timing light to check if you wish, again the cost is little or nothing. The most likely causes are bad crankshaft seals and/or the need for new seals on the intake assembly. The metal carb fits into a flexible fitting between it and the reed assembly. When the fitting gets old and hard it tends to loose it's ability to seal. Often they will develop cracks that let in air which leans the fuel mix. When the engine warms up the cracks widen and the engine runs poorly.

you might need a new clutch basket, it could be worn take out clutch plates and check for groves in the basket they may be sandable but you might have to replace. good luck

anymore info

try to compleatly shift down then half up with the clucth in

It sounds like your starter motor may be bad.

nevr give serial over the air--people can make keys--call a dealer and he can tell u

my oil light also comes on after riding my bike, I have filled up the oil tank with castrol 2t oil but the light still comes up. The previous owner never had a problem with it.I washed the bike literally everywhere as it wasn't looked after and i think it is electrical problem as some some water may of got the electrical circuits. Have you washed yours or has it randomly just come on?

My 2001 raptor 660 starts when it's cold and runs great but if I shut it off when it gets hot it does'nt start back up until it cools down

You need to check the voltage to the HT coils when the engine is cranked , if there is no voltage then the +B to the coils must be checked also the LT switching triggers to the coil.
Make sure that the fuel setting and flow is correct.

YAMAHA 80 c c =80 cubic/ cm

This sounds like a broken clutch cable.

There are many possibilities for this problem:---bad piston rings, clogged air filter, carb problems, wrong plugs.
First check the spark plug condition, when this problem occurs:-----1) If your spark plug is dry and burnt brown its normal.
2) If your spark plug is whitish it means its to lean.
3) If your spark plug it fouled with black oil over it that means your bike is running to rich. ------------- Try playing with the idle screw or air fuel mixture screw on the side of the carb.
The idle adjustments are easy...........

1.) Adjust your throttle cable free play.
2.) Start bike and warm up.
3.) Once warm, turn idle up a little high at the adjustment and then adjust low speed pilot screw to achieve the highest possible idle w/o turning any other screw.
4.) Adjust the idle screw down to an acceptable level. ------------ There should be the highest idle. That is where the pilot circuit is most efficient and gives the best off idle performance. ---------- click this link below for more help:--- http://technoanswers.blogspot.com/2011/05/spark-plugs-keeps-fouling-on-2003.html ------------- This should help.thanks.helpmech.

your cluch pack your push rod or basket could be on its way out start saving money

first off make sure the oil gas mixture is correct and mixed very well.... have the carb cleaned out very well or even rebuilt, jetted and adjusted...

take your flywheel off then turn youe engine over while you watch the crank spin when the lobe on the crank moves the points to the hihest spot thats the point where you set them i think its like 10 or 12 mm