tskyyc

I visited my mom on the weekend. She kept all of my Lego from childhood in a big tub. I dumped it all out and played for hours with my 2 young daughters. I found some semi-dismantled chunks of old Space sets that I recognized so I downloaded some instructions and re-created them.

Is that a 6 cylinder engine? I like it... I'll definitely buy one. I have a minor pet peeve with the engines and that the crankshafts can only be arranged with 180 degree throws. A 6 cylinder engine with 30 degree crankpins would be cool.

My set was missing a 8L axle with stop

You have one of the planetary gears (little tan ones) on the wrong side of its carrier, causing the front and rear jacks to try going in opposite directions. Flip one of them to the other side of its carrier.

4:6 9:4

Looks great but I would refer to is as a 990cc V4 superbike... The design is very reminiscient of the Ducati Desmosedici. Particularly in the way you've mounted the headstock on a trellis subframe bolted to the cylinder heads and the way the swingarm pivots in the engine case. All it needs is a simple trellis subframe for the seat and a bit of bodywork and it will be perfect!