Occasional, Weak Spark Harbor Freight Predator 212 Question

[Auto Doc's]

A weak magnet issue is very uncommon. Old Tecumseh engines had a lot of problems like that, but that has been many years ago.

I have not run into any HF motors with a failed flywheel magnet.

If it will hold/grab a 10" steel adjustable wrench I would say the magnet is not the issue.

Could be you have a poor-quality aftermarket coil.

I have had good luck with coils off of eBay (so far).

Just for curiosity, flip the coil over where it mounts and set the air gap and try it that way. I've seen some strange things happen with aftermarket parts.

I don't recall reading if you had checked the flywheel key to make sure it is not partially sheared.

 

[PGB1]

A weak magnet issue is very uncommon. Old Tecumseh engines had a lot of problems like that, but that has been many years ago.

I have not run into any HF motors with a failed flywheel magnet.

If it will hold/grab a 10" steel adjustable wrench I would say the magnet is not the issue.

Could be you have a poor-quality aftermarket coil.

I have had good luck with coils off of eBay (so far).

Just for curiosity, flip the coil over where it mounts and set the air gap and try it that way. I've seen some strange things happen with aftermarket parts.

I don't recall reading if you had checked the flywheel key to make sure it is not partially sheared.

The magnet holds a wrench quite well, so I'm confident.
That is an interesting idea to flip the coil upside down. Unfortunately, when I tried this there was no way to get the plug wire to the plug. It's a goofy design where the wire has to snake under & through things.

The coil is, indeed, aftermarket. I'm on the third one. In sunlight, I did have a spark with the tester and with the plug grounded. It's not dark outside and the machine is too heavy for me to drag to the shed, so hopefully tomorrow I can test it at night to find if the spark is strong.

Should I have a good spark but no firing, would the next test be compression? What's a good number for compression on this small engine? I've read things from 30 to 200 psi, so the internet sources are quite varied.

Paul

 

[PGB1]

I apologize for such a delay in getting back to the project and reporting here.
Three coils later, I got a good one. The gap is now 0.006". The spark is strong and the engine starts, but runs lousy. I suspect maybe the carburetor, but don't know for certain.

To keep the engine running, I have to have the choke nearly fully closed and the RPM lever very, very high. The RPM is so high that the machine is louder than any small engine I've ever heard and sounds tinny (as though something is about to break.). I don't know the RPM, but hopefully can check it later.

Thank you all for helping me with the spark problem. I very much appreciate your guidance.
Paul