The Honda GX120 is a popular choice for the SB45 and is perfect for a 20" machine....
Take a peek at the specs....Click HERE

With the knowledge that, brand new, the Scott Bonnar 20" machines were approx $1800.00 each....spending a few extra dollars on this engine would be well worth the effort and the machine, well maintained, will give you hours of mowing pleasure, and last a lifetime. wink
PS. Here are the specs for the GC160 engine....Click HERE
cheers2

Last edited by Deejay; 24/10/13 09:30 PM. Reason: Added Specs
Please do not PM me asking for support. Please post your questions in the appropriate forums, as the replies it may receive may help all members, not just the individual member.
Kindest Regards, Darryl grin