The original Lambert forks where made in one piece from blades to crown with a 2" extension over which a steel steerer was fitted and bonded (some were also pinned). The aluminum was prone to fatigue at the crown which would have the fork snap at the crown race, leading to an instant faceplant, hence the name "death fork".

These were recalled, and replaced with a similar looking fork, except that a roughly 1/2" diameter pin was inserted thrrough the bottom, extending well up into the steerer. This buttressed the critical area, resolving the crown failure issue, but there were still some QC issues relating to bonding and pinning which allowed for separation over time, but usually with less catastrophic results.

In the end Yamaha scrapped the aluminum fork entirely and replaced it with a steel fork as pictured in an earlier post.

The OP can remove the front wheel and look for the steel pin showing at the bottom of the crown. If there isn't one, do not ride this fork at all. Not even for 100 yards across the parking lot because there's no way of knowing when it'll fail with predictable results. If it does have the steel pin, it's OK for short ceremonial rides but isn't to be trusted for extended use or at high speed.

BTW- changing the fork disn't solve all the problems with these bikes. The stronger , stiffer steel fork was too strong for the frame, and bikes with it suffered an unacceptably high number of heat tube joint failures.

Overall, Lamberts were a good example of going too far too fast to shave weight and offer features at a good value, and outpacing the engineering needed to do it right.