OutdoorKing Repair Forum Forums Repairs and Maintenance Questions on Walk Behind Lawn Mower Frames Question On Scott Bonnar Cylinder Mowers SB 45: how to adjust chain tension

My apologies if this has been covered before but I can't find a discussion on adjusting the chains on a SB45 properly. I can get good tension on the two long chains but there seems to be too much slack on the small chain of my mower. Would someone point me in the right direction please?
Cheers

Hi Beammeup, presuming you have adjusted the cylinder to bedknife clearance correctly (it affects chain tension) loosen the nut that attaches the long chain plastic tensioner and push it down to give some slack in the two chains that run around the cylinder cutter sprocket.

Look behind the largest sprocket and undo the nut slightly that holds the bracket to the side frame and do the same to the lower nut of the same bracket and slide the large chain sprocket upwards until you reach the correct small chain tension...about 1/2" play will do it...lock up both the nuts firmly. Slide the plastic large chain tensioner back up so as both the long chains are tensioned correctly and lock the nut up firmly.
Re-check the cylinder to bedknife clearance again and if all OK, replace the chain case cover and you're done.

Thanks Deejay. Have I understood you correctly...the black chain tensioner thingy actually serves to bring the right tension to both the longer chains?

Hi again Beammeup, yes, you are correct, it just slides up and puts the tension on both the longer chains. Simple set-up, but effective.
The new video is being edited by Joe Carroll as we speak, of the re-installation of the cylinder reel and soleplate, including clearance adjustment of the reel to the
bedknife, also mentioning chain tensioning and greasing.
I hope you find it interesting...