OutdoorKing Repair Forum Forums Repairs and Maintenance Questions on Walk Behind Lawn Mower Frames Question On Scott Bonnar Cylinder Mowers Ouch hair line frame crack found on my SB45 20'

Hi all

Have other restorers noticed when striping the frames back for painting a hairline crack in the frame around where the engine bolts on to the frame. I take it that the common fix for this is to weld up a 3mm plate in the underside of the frame rails where the engine bolts onto the frame and weld new SAE/AF Nuts on to the new plate or simply insert the plate and then use nyloc nuts for the engine.


Opinions or thoughts.


Thanks in advance

-greg

A picture would be helpful. IIRC it is very common on the later (2 rail engine mounting) SB45s for the front rail to crack where the inboard engine mounting bolt goes through it. I'll leave the discussion of how to repair it to Deejay, our Scott Bonnar guru, but it would be best if you've already posted pictures by then.

Hi Greg, yes mate, this is a common prob with the 2 rail chassis SB 45's and has been discussed here many times.
It is caused by fatigue due to the vibration of the engine and can be rectified by many methods, each method dictated by the severity of the crack. I have seen some rails completely fractured.

Can you please post a pic of the affected area, using on inline-uploader (Instructions are HERE ) and we can discuss which would be the best method for your machine.