I've never read anything about the YaK-43 not having lift jets, but no source seems to identify what type they might be.
The forward "auxiliary combustion chamber" fed with NK-32 air-bleed is often mentioned, sometimes as a possible fit. I don't know where that would be located, I always assumed it was ahead of the lift-jets in the forward fuselage, but piping air and fuel that far forward and wasting internal space when you have lift-jets seems odd to me as does duplicating the role of the lift jets. Maybe it was intended as a trim device with the ability to provide extra lift at high TO weights?
The YaK-43 seems very sketchy, very little detail at all which makes me wonder how much of a serious project it was.
Yak-41M : Proposed production aircraft with large LERXs (leading-edge root extensions) and other improvements, particularly in the avionic suite. Yak-43 : (Izdeliye 201)A proposed development of the Yak-41M 'Freehand' equipped with Kuznetsov NK-321 engines.