Hi Stuart R, and a warm welcome to the forum. It's great to have another SB Model 45 owner on board. grin

Stuart, grumpy has given you good advice there re your safety....also his diagnosis may prove correct. However, this could prove to be a clutch problem or a combination of both. wink
As grumpy has explained, we need the pics he has suggested taking so we can ascertain what is happening plus some good pics of the cylinder reel, bottom blade and the reel adjusters on both sides; I can then step you through the repair process.
I will need you also to remove the chain cover and take some pics of the sprockets and chains...particularly the sprockets where they are not covered by the chain...this will let me see their condition. wink
Please use the OutdoorKing inline uploader; for instructions please click HERE
Please do NOT operate the machine until we identify the prob....it will only cause more damage.
Once again Stuart, :welcome: to OutdoorKing.
cheers2


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