DT2 wont start?

Out with a buddy over the weekend, hes having issues with his 80's DT2 and wonder if there is something that is prone to going wrong on these.

He had it running fine and then after turning off it wouldn't restart. Removed the plug and doesn't look wet and getting spark, spraying some quick start fluid it will fire up for a few seconds before dying so definitely fuel related.

Its had a new spark plug, carb cleaned twice but anything else that's worth checking on these? I have told him to check the fuel tap and not sure if these can clog easily, tank was cleaned when he first purchased it but not having a fuel filter theres a chance of clogging thing up.

Def a fuel issue! It is always best to have a fuel filter on there, the slightest bit of dirt can clog the system and then you have problems, best would be to clean out the complete fuel system and add a filter. Also check there are no leaks, if the vacuum is not sufficient you won't get fuel through either, make sure there is ventilation at the tank.