Saw will die with full throttle.

[Hunter]

Having problem with my saw MAC 838 38 cc saw.

The saw will start easily, and rev nicely while throttle leaver is half way out but it wouldn't idle , it will rev up and respond nicely without hesitation to my finger on the throttle but will die suddenly with full throttle.

I had the saw from new and never changed factory carb setting.

I have checked and changed fuel line, fuel filter, air filter, cleaned the carb which was already clean and rebuild the carb with service kit also changed spark plug.

I have also tried to run the saw with fuel cap off in case vent hole is blocked.

I have Pulled the muffler and piston looked fine, checked compression and it is 155.

Any suggestion.

[spandit]

Mine had similar symptoms and only after failing to get it going at all I found the coil pack isn't working - wonder if it's been intermittent for a while. Are you definitely getting a spark?

[Hunter]

How to test coil pack and where you look for spark.

If it is coil pack would it run nicely on half throttle but not idle.

[chuck norris]

Did you replace the fuel pipes at the same time that you did the carb?

[Hunter]

Did you replace the fuel pipes at the same time that you did the carb?

Yes I did

[Stubby]

You need Spud .

[chuck norris]

What sort of ignition system does it use?

[Hunter]

What sort of ignition system does it use?

Not sure, I am still learning 😢

But it is like this

MCCULLOCH MAC CAT 318 335 436 440 441 IGNITION COIL SEE LISTING FOR MODELS | eBay

[Hunter]

I have thought that with ignition coil problem saw will be difficult to start?

[spandit]

Mine used to start fine but die on full throttle. I tested the coil by removing the recoil starter and spinning the motor with an electric drill - making sure the plug is earthed by touching it to the engine. No spark at all.