Some physical/chemical facts for the beginning.

(1) Motor fuels are hydrocarbons, mainly composed, as said, from carbon and hydrogen.
(2) Diesel fuel has notably higher carbon to hydrogen ratio than petrol.
(3) Carbon rich fuels need more mass ratio of air to burn completely, to clear carbon dioxide and water, as carbon takes two oxygen atoms for on carbon atom, and hydrogen takes one oxygen atom per two hydrogen ones.
(4) Diesel fuel has notably higher boiling temperature range than petrol.

That said. As carbon rich fuels have more carbon and need more oxygen to burn, they tend to start to soot easily when burned incompletely without all the oxygen needed. Then, when engine is first started, it sure runs at sub-optimal cycles. For low RPM, compression will be poor and air dose will be lower than usual. Also, engine does not start immediately and fuel doses injected on previous cycles will partially stay in the cylinders making excess fuel. As diesel has high boiling point, extra fuel will stay for long on the cylinder walls. All that makes for low oxygen and too many fuel, making the engine to soot for some time. Also, when engine is stopped, some oil enters the cylinders, acting then as a fuel and taking some oxygen to itself. Even heavily worn petrol engines can soot because of this.

Older briggs and Stratton mowers with the 35 classic type engines are brilliant mowers. I have owned different mowers with that type engine and they have always been amazing for me and if they have ever broken down it has been just a simple strip down and full clean of the carburettor, fuel tank and fuel filter, and oil change, then Fit it all back together and they have always ran beautifully afterwards. Best mowers out there and the chassis has always rotted out whilst the engines have still ran stunningly

As for my strimmer, i have 2 branded TITAN and i am having running issues with one of them that will start but just die.

The other one runs well ish bur cuts out mid cutting. But restarts instantly

Anyone know what i can do? Or able to give advice?

Cool 😎, so that ride on territory?, I forgot how big lawns usually are in the US!

I agree that electric is good for smaller yards, but gas is the best for big yards. Ours is an acre and a third.

https://www.youtube.com/watch?v=6wze8ucfW1g
A drunk truck driver hits a traffic light right before it turns red, and disabling the traffic lights system.
The full article: https://www.ynet.co.il/news/article/Hk11Sx8EJ00 (Please translate from Hebrew to English).

At the beginning of the load test, the maintenance initially starts the engines of the generators and after the engines reaching working speed, immediately disconnecting power to the hospital and than connecting it to the generators.
I hope that @Medved and @Ash know what this phenomenon happening.

Also: in this video ,you can hear at 0:42 a noise of a pressured air releasing that one of the generators emits during starting.
Why this is happening?

We’re down on drivers today at work, so in between maintenance work I’m currently taking cars round to our paint shop, so far I’ve taken 2 BMWs, a Merc and a SEAT, as well as sort a signal issue out on the main gate and fit a new airline in workshop 1 😎

Diesel engines usually do this under load?, either theses a slight load on them when starting, or its an automatic cold start feature where more fuel is injected before the combustion starts?

In this video:
https://www.lighting-gallery.net/gallery/displayimage.php?pos=-228053
You can see the two exhausts of two of the generators of Carmel hospital emits thick black smoke when starting.
Other generators there don't do this, and I think that petrol engine don't do this during starting.
Why this is happening?

Most of our garden equipment at work is Stihl, but at home I won’t entertain anything that not electric! 😝, I’m not really a great lover of high revving, heavy, smokey noisy 2 stroke engines!
My neighbours lawn is half the size of mine, and he’s bought the biggest loudest petrol mower he could find! 😱, whereas my 1200 watt Mountfield does the same job flawlessly! 😎