Identifying New vs Older Style 459 Engines

In the first quarter of 2026, Harbor Freight decided to introduce a variant of their 459 engine into US commerce.

These new engines are NOT compatible with ANY of our kits and we dont have a “fix” for them   The ONLY option is to swap it out to an older version or switch to a 420   

Many people are having a hard time telling the difference between the 2 engines so we are writing this article to help with that.

The easiest way to tell if you have the Older Style which is compatible with our kits and charging systems is that they have black gas tank brackets.

The newer style has gas tank brackets that are cast aluminum and built into the crankcase housing.