03 TXT Robin EH29C - weak spark?

[Mooncarter]

Good!

[Cartmaster]

As you say, just check valve lash first, it's such a simple job and very common fault on these engines. It is always the first thing I would check on poor/no start conditions. And as you say, eliminates that from the equation. Don't use carb cleaner if you suspect valves as it may not fire and then you will definitely wash out the rings. I doubt cranking without fire so far will have done any harm. Once it is running, feel free to run some carb cleaner but personally I prefer to strip the carb and do a thorough hand clean or sonic tank clean. Let us know what you find with the valves. If you end up with a lot more thread above the locknuts on the inner two valve adjusters then expect to do valve replacement soon as they will be sunk in the head and worn out

[Anopsis]

So it looks like I may have been the problem all along.

First, I did run the valves - I one side was tight, so was E on the other. Adjusted them, still no start. I mean, there's air, fuel and spark, right? Plugs were getting wet - fuel. Spark tester was lighting up, and I was using new plugs with the proper gap.

So, air. I was assuming it was getting air.

This is a bit humiliating to say, but it would appear as though I was only pressing the pedal far enough to start the engine turning over, but not enough to open the throttle and allow for adequate airflow.
Pressing the pedal another inch (that's about 2.5cm for you, Cartmaster) and it started right up!

I have started it many times since discovering this yesterday, so it seems we're all good now. I suppose if I had someone with me that had experience, they might've spotted my error, but it took me time to figure it all out.

Thanks for the help!

[Cartmaster]

well at least you have it running now and done a valve lash service LOL. no worries about inches my friend, we may be in europe but at my age i still do imperial. Am i the only Brit that has full sets of imperial sockets and wrenches i wonder.