Zetec starter motor for tiger avon

I have the new starter motor Lucas part number LRS707 and it engages with the flywheel perfectly. The only thing i had to do was take an angle grinder to the side of the sump to shave a few millimeters off of the side to allow clearance. Other people have cut a section out of the sump and welded in a plate but i found this wasn't necessary as i only needed a bit taken off.

Starter motor problems....

It seems i may have the wrong starter motor, the one i have is a lucas LRS543 on the advice of someone in a internet forum. I bolted it up to the engine earlier and it looks like it is perminantly engaged with the flywheel, which will mean it will be spinning all the time. I have just read on another website that u should use a lucas LRS707 I will do some more investigating tomorrow.....