Not sure how the SP works on them either.
Had a few of those 20 inchers here, none of them SP's. Where that cover goes to the non SP mower have a metal cover over a hole about an inch and a half wide and 2 and a bit high. Id say the belt goes in through there.
Im not sure that its the real deal. The holes in the cover on the front, those had a dress cowl on the front, toro mower rings a bell. And the flywheel brake mechanisim on the front is an american made mower thing.
I would say that motor is not what was originally on that base hence why the SP is not working.
Perhaps the SP Rovers were shaft driven and had Honda motors.
Rip the cover off, whats under it???
You could always put a power torque on the vantage base and use the 4 stroke for bits.
