Topic: Benelli 750 Sei - CB500 engine swap?

[jacquesleclochard]

The benelli is based of the CB500 (source WIKI), so would a direct swap be possible? I found a hardtailed frame from a benelli. The engine was sold seperately, and the hardtail is going for cheap. I'm thinking about picking it up and sticking a 500 engine in it. Possible?

[Jerry Rxman Griffin aka MuthaF'er]

You have 2 more pistons to add? CB500 is 4 cylinder and the Sei means 6.

[scunny]

he has 2 less if going from the Benelli to the Honda motor.
at the least you could shim the engine mounts. don't know the width of the mounts for the sei.

[scottly]

Why would someone hardtail a Sei in the first place?

[FuZZie]

I went and read that wiki jacquesleclochard
I got some better info from this http://books.google.ca/books?id=JVju-J_-AawC&pg=PA108&lpg=PA108

Seems the Sei used the same frame as  benelli 500 (meaning mounting had nothing to do with cylinder count).
Although the motors are similar it's based on design it's not a actual Honda motor so mount points are not going to be the same and Benelli moved a few internal things too.
Next Honda and Benelli both used a double down tune frame (whatever needed for mounting could be welded to the Benelli frame I'd guess).

IF: you have a Honda 500/550 parts bike and skill, I think this is doable.... but it's sure not drop in.
 
DISCLAIMER: don't do this on my word I'm guessing from very limited info!

[754]

 If the Benelli mounts are same width, or wider, should be easy... & I doubt the mounts were narrower on the sei...