Rebuilding the motor 1: building an engine stand.

There are probably an infinite number of ways of building a suitable stand for the motor but here's what I did. I ordered 25mm steel box section with a 2mm wall plus 25 and 30 mm flat steel bar 8mm thick. In addition I have 20mm od steel tubing with 2.5mm wall and 15mm steel round bar. Here are my initial sketches. The stand consists of an "H" shaped base. To this is fixed a vertical mounting upright bearing a hollow tube to accept the pin from the swivel mount. The motor itself is mounted on a 90 deg bracket attached to a swivel mount that slips into the mounting tube.

The design can be adapted, I think I might make the base a little wider and the upright a little shorter if remaking as this will improve stability. However, this is as always a record of what I actually did so here it is warts and all... and its not intended to be an advert for my welding. I am of the low skill welder category; any weld you walk away from is a good weld for me! Basically if I start with two bits of metal and stick them together then that's fine. I will say though that this 2-8mm steels are easier to weld than thin car body panel steel.

Components of base, assemble 2x20 and 1x 35 lengths of box section to form an H. Make upright from 25cm length of box. Grinding the end to accept 15cm length of 20mm tube. Weld this to the upright and fix to the H as below. Note weld nut inserted as clamp. 

Swivel mount, fix a 20cm length of 15mm round bar to centre of a 10cm length of 30mm flat bar using screw and weld

Assemble engine mount using motor to ensure fit. In my case this resulted in 10 and 18cm lengths of 25mm flat bar. Grind ends to fit with crankcase

Building the stand:

Basic components, 25mm box (2 or 2.5mm) and 25mm steel bar (8mm)

Engine Mounting Bracket:
Cut two convenient lengths of 25mm flat bar and drill 8mm holes on the centre line 1.5cm from one end of each. You may (will) need to grind the end profile of both to remove wickedly sharp corners and ensure that the bars can fit against the crankcase profile

Vertical section of mounting bracket ground to fit with the crankcase.

Slip M8 bolts through these holes to hold the bars loosely to the motor

Attach the two bars loosely and swivel them to form a 90 degree junction, mark and cut to length.

Align the bars to form a 90 deg junction, scribe and cut. Refit the bars and weld together to form a mounting bracket.

Bracket welded together, this ensures it will fit!

Swivel Mount,
The bracket needs to be able to swivel so to make the swivel mount cut a 10cm length of 30mm flat bar and a 20mm length of 15mm round bar. It is possible simply to weld the two together, but I wanted to strengthen the join so I drilled a 6mm hole through the 30mm bar 3cm from one end on the centre line. I then drilled and tapped the round bar to M6 and fitted the 2 bars together with a screw. I had intended to use a countersunk screw but didn't have any so I used a button headed screw and welded that into place before grinding it back flat to the bar surface.

30mm bar screwed and welded to 15mm round bar; screw head and weld ground flat

...and welding in the other side of the round bar to form the swivel joint.

Front side of bars welded together

Finally the mounting bracket was welded to the swivel joint along the centre line of the 30mm bar below the position of the swivel (round bar) so that the weight of the motor would hang vertically from the joint.

Welding the motor mounting bracket to the swivel joint

Base,

Meanwhile construct a base for the stand from 25mm box section. Cut two 20cm lengths for the sides and one 35cm length to join them in an "H" shape and weld together

Base Upright and Swivel Tube,
Cut a 15cm length of 20mm round tube (15mm ID) and drill an 8mm hole, 3cm from one end.

Run a nut up on an M8 bolt

Drop that into the hole

Weld on the nut making sure that the bolt isn't welded in too!

M8 nut welded to tube

Make the upright by cutting a 30 cm length of bar and filing the end to accept the profile of the 20mm round tube. If making this again I wouldn't make this quite so high, 20 cm would have been fine.

Upright profile filed to accept swivel tube

Weld the pre-prepared tube onto the top of the upright

Swivel tube welded to upright

Weld the upright to the base

Upright welded to the base, I straddled the side to centre join of the "H" to try and strengthen it.

The swivel mount can then slip into the tube

Assembled stand- I did get a bit of a bend in the swivel bracket but it should work fine.

The motor then bolts to the stand using 2 x 55mm M8 bolts fitting washers against the crankcase

Motor mounted to stand. It can be swivelled around the swivel pin to any desired orientation and fixed in that position using an M8 bolt tightened through the weld nut. It will probably help if some location hollows are drilled into the swivel bar as well as tapering the bolt end so that the bolt can grip the swivel pin better.

The motor can be swivelled and secured in any position using an M8 bolt through the weld nut to clamp the swivel pin inside. It would probably help to drill some location points into the bar and shape the end of the bolt to help it locate and grip better.