Are the coils interchangeable between sides? Can you test the know works on the one you know does not to rule out a bad coil?

 

I get normal reading from the coils, I'm trying to test the stator but no idea how to remove the goddam flywheel

 

An impact wrench will spin the flywheel bolt off. No driver put a penny between a couple of gears to hold the crankshaft still ;

Bill H

 

The crankshaft still seems to spin even when i put it in gear and hold down the break to stop the wheel moving. Doesn't seem to make sense

 

Why take the rotor off?, there's nothing to be gained by removing it (unless you want tp service the electric starter clutch).

 

I need to take the flywheel off to test the stator underneath.. unless there is another way?

EDIT: I've also tried the rope/ shoelace in cylinder trick with no luck, and tried a C clamp to hold it in place when turning the bolt.

 

I might be missing something but why check the stator? It recharges the battery but doesn't directly affect spark.

I would just recharge the battery and use a multimeter to make sure it's healthy and fully charged. A dying battery would result in a no spark situation and would also explain why the starter kills it so quickly. I've found the battery to be a key variable when diagnosing a no spark issue.

Then check each coil directly: connect a jumper wire from the battery's positive terminal to the coil's black wire and check for spark by holding the spark plug against the cylinder fins and kicking the bike over. **Don't leave the jumper wire plugged to the coil for more than a minute or it'll fry your coil. Just leave it connected long enough to check for spark.

If there's no spark, check to make sure the spark plug boots have a clean connection to the coils.

If there's still no spark, try again with a known working spark plug with the correct gap.

If there's still no spark, your coils are probably dead (unless it's an issue with your points or condenser which seems unlikely since the bike has been running).

All these steps should work regardless of the condition of your stator. Like I said, I might be missing something but this is a diagnostic that would work on a CB125, CB350 and CB450 so I assume it should apply to a 250 also...

 

if it was a dying battery it still would generate a spark when i use the kickstart though? cant seem to get a spark or even at least a very faint one, when grounded to engine fin. Ignition coils give normal readings so isn't coils.

In many of the diagnosis threads i've read, they advise to check the stator: Ignition Diagnosis for CB/CM 400/450 and CB450SC manual...

 

This sounds like a bad condenser check the points for a pit on one side and a hole on the other. you can imitate turning the engine by turning the switch on then use a screwdriver to open and close the points this will fire the coils. Coil secondary runs 10,000+ ohms just so you know. If there’s no spark at the points suspect a bad coil disconnect one at a time until you get spark at the points if no spark check the wires between to coils and the points. Ignition points are the only moving part in the ignition system and need to be serviced as they wear down the ignition timing retards (yes points affect timing). I suggest you tune the ignition points and condenser then charge the battery and ride. I hope this help. Take Care

 

Thanks pal, I don't think my bike has points or a condensor? I can't find one, I think its an electric starter. I am so confused now. is there nothing under the left crank cover that is related? i think it's just the stator under there.

)

 

From your photo you have an ing. trigger on the fly wheel
This model has what Honda called ing coil assy. I have never seen one but must work like a CDI.It also has a condenser. If you dont have a Honda full service manual You will need one and a elec diagram. I cant help you .

You might try motocycleforum .com or bikechatforum.com

 

I've just checked all readings from the stator,

Readings are all ok, except- Blue and white wire is giving me 5.4ohms; should be more like 203...i think

Ignition /kill switch in all tests just showing 1 (infinite) in all positions (black/white wire from CDI) to negative terminal on battery.

Any help?