Yamaha yz125 2008 Have no spark on the sparkplug. what is the reference valuees for the coil and for the sparkplugcap? Gearwheel

No Spark?
Then you have a problem with your ignition and that needs to be fixed. Get the manual if you don't have it or find a friendly shop that might help you.
See if you have power to the ignition; you don't find out why.
The sparkplug wire you replaced? How? It is part of the coil as one unit.

Hi,check fuse,check sparkplug,check the coil lead and coil,then check stater has a spark.
good luck hope you get it sorted out.

Problem could be a few different things. Not sure on all the ignition parts on that bike, but could be a bad sparkplug cap, wire, coil or magneto. My recommendation would be to first take the spark plug cap off. Trim a bit off the wire and put the cap back on. Over time spark plug caps move quite a bit and wear out the wire inside cause a weak connection.

Thanks

Please check your :
- coil
- sparkplug and
- fuel line
For malfunction.

Regards

swap the coil and if still no spark on that coil it will be ignition(spark) box

Put a new fuel filter on it and when it stalls take the fuel line off the carburetor to check if gas is getting to the carburetor. If it is remove the sparkplug put the wire on it and ground the nut of the plug on the engine block and pull the cord and check for spark between the sparkplug gap. If no spark you might have a faulty coil, when it gets hot it has no spark.

CDI IGNITION might have gone bad but i doubt it. check all your fuses and make sure they are good!! You have to get 12VDC to coil then you should get spark to sparkplug. Good luck and let me know how things turn out. HDTV GURU JAY

check your distributor unit or as they call it on my honda 87cbr, a pulse generator. You can switch coils around (if they are exactly the same!).. see if problem is now opposite!...if it changed... well its new coil time. but my problem wasnt the coils which i was almost positive it was because i wasnt getting any spark to #1 or #4 ...i didnt check 2-3 but im sure it wasnt getting any spark either because the bike wouldnt even hint at starting. it cost me two hours of trouble shooting and $50 for the used part...starts right up now everytime...hopes this helps.
Can i get a rating too...thanks!

Hello,

Remove both sparkplugs from engine. Plug them back in the sparkplug cables and let them rest on the engine.
Make sure your battery is well charged.
Check for sparks while kick-starting...
Interchange the sparkplugs in the cables:
-Same plug give sparks: replace the spark plugs.
-Same side of engine sparks: interchange the low-voltage connector at the ignition coils.
Give it a try:
Same engine side sparks: Replace the defective ignition coil.
Other side of the engine sparks: Check the circuit harness for loose connectors, and/or Clean-replace the breaker points ( left side of the engine carter ).

first check the sprkplug to see if it is making sparks,if not replace the sparkplug and try again,if still no joy check that the sparkplug cap is tight on the lead,if still nothing the rear coil may have gone faulty,hope this helps