where to start?

i have a hyper 7 running a sts28 in it.i have gone through 3 clutch bells and 2 spur gears in the space of 6 tanks of fuel[]

i have the gear meshed properley,all engine mounts are tight.

after i lost my last clutch bell i pulled the lid off to check every thing was tight and it was.

i then started it up again.with my hand i was able to move the engine very slightly sideways causing the spur and clutch to touch and separate.

i dont know wwhy this is happening but it is becoming very expensive[:@]

any help would be appreciated.

cheers dave