In the redhead engine, it wasn't available in the 600 size until 2000. They did have the 600 size available in the SRX in 98-99, but what this post is about is a redhead 600cc engine. If it in fact is a 98, and a triple, then it would have to be a 700cc redhead. If you look at the 600's in the Yamaha parts fiche, the 600's in 97-99 are twins EXCEPT for the SRX. Not trying to be a know it all, but it actually might be better for seller, as the engine would be newer than he thought.