126M02-6675-F2 Won't Run - Replaced Carb & Flywheel Key - Still No Go

[GitPicker]

Hello,
My son mows the lawn, so yeah, had to replace the flywheel key when the cord damn near pulled my arm off. After key replacement, the mower sputtered, ran a second or two, and then stopped. Replaced the carb with a new one, drained the fuel, drained the oil, checked for spark (yep), took off exhaust/muffler and put back on, tried starter fluid, spun the blade to check for compression (definitely has compression, but how much I can't measure).

I do not know where to go from here. My only thought is to take the bulb off the new carb (from China, 10 bucks) and see if perhaps there is crap in it.

Thanks for any help!

 

[hlw49]

Did you torque the fly wheel bolt/nut when you replace the fw key. If not it would probably cut the key again. If the fw key is cut it will still have spark since the key has nothing to do with whether it will have spark or not. It just times the spark to the right time when the piston is at tdc on the compression stroke. It will also fire on the the exhaust stroke. As long as the magnet on the fw pass by the ign module it will fire.

 

[ILENGINE]

Was the flywheel properly torqued after replacing the key. Could of sheared the key a second time.

 

[GitPicker]

Thanks hlw49 and ILEGINE. I'm not sure exactly how to torque it, but I did tighten it. After trying to start it numerous times, I undid my previous work and checked and the flywheel key was still in the same place. I put it back together and kept at it, but I haven't checked after the last 40 pulls
To torque it, do you recommend just extending the handle of my ratchet?

 

[ILENGINE]

Torque to 55 lb/ft or 74.5 Nm

 

[StarTech]

You need a torque wrench. Many auto part stores have a loan a tool program. Just using a ratchet will tighten the retainer but you will not how pressure you are applying and can easily damage flywheel taper or even bust it.

 

[sgkent]

you may need a tool to hold it from turning too. Check the blade to see if it is loose. Also double check the coil air gap if it is that style coil. I don't understand about the cord "pulling" your arm off unless you mean it back fired and tried to spin backwards.

 

[StarTech]

you may need a tool to hold it from turning too. Check the blade to see if it is loose. Also double check the coil air gap if it is that style coil. I don't understand about the cord "pulling" your arm off unless you mean it back fired and tried to spin backwards.

Exactly can happen with a sheared flywheel or ACR failure. I had Honda GX390 actually jerk back so hard that I had nearly dislocated fingers. Not a fun thing to happen especially you depend on your hands to make a living.

And he will need a tool to keep the flywheel from turning. Blocking the bar blade can work many times on walk behind as long as the blade is not clutched.

 

[GitPicker]

Hello all, thanks for your help. I'm embarrassed to say it was the spark plug. The old plug had good spark. I checked it twice! Anyway, since I had replaced everything else, 5 bucks for a new plug seemed like a good idea. I put in the new plug and it started on first pull and ran like brand new. Hopefully someone can learn from my mistake. I do need to torque the flywheel nut though, but at least I can knock down my 10 inch grass before the HOA comes complaining.

 

[ILENGINE]

Hello all, thanks for your help. I'm embarrassed to say it was the spark plug. The old plug had good spark. I checked it twice! Anyway, since I had replaced everything else, 5 bucks for a new plug seemed like a good idea. I put in the new plug and it started on first pull and ran like brand new. Hopefully someone can learn from my mistake. I do need to torque the flywheel nut though, but at least I can knock down my 10 inch grass before the HOA comes complaining.

One thing that I have learns in my many years of repairing mowers is never trust the spark plug.