Crankshaft nut unscrewing

[pgrbff]

I've recently finished building an Avro, it was an early kit that had sat in someones garage and hadn't been built. I've tried starting it twice now but I'm clearly doing something wrong. The Avro crank nut holds on the fan/clutch assembly, and the nut screws on clockwise. The starter spins anti -clockwise, unscrewing the crank-nut every time I try to start it. I have used loctite at the top of the crankshaft nut as per later instructions.

[del19_82]

you need to lock the piston and tighten the nut as much as you possibly can! I would put quite a bit of locktite on there as well just to make sure!

Fast-lad sell a tool that will lock the piston for you without damaging it

[tonystevens]

I dont know about the Avro but it
Shouldnt be doing that:confused:
If all else fails do you have enough room to put a secondary lock nut on?

[pgrbff]

I have the tool, infact I think I have 2 or 3. Anyone want to buy one? I used a 1/4 ratchet and 12mm socket, and went as tight as I could. It still came off with the first burst of the starter.

[pgrbff]

Not possible because of the design. The crank nut has a reverse thread in the top into which the starter hex screws.

[tonystevens]

What engine do the tools fit,ill take one if either YS91sr or OS 90 hz:)

[pgrbff]

I have a brand new OS one on BMFA classifieds, I know it fits the 91SX, not sure about the HZ.

[electricsceadu]

clean the threads and degrease them
use plenty of high strength loctite
lock the cank and tighten very tight
leave for a good few hours
when trying to start the engine first take the plug out