The original message said the bolt was stripped, which is easy to do
w/o a torque wrench. But it's also noteworthy that it isn't necessary
to have a loose cover bolt, tossing oil, to cause big problems. The
maintenance manual states that an air leak past the O-rings can cause
oil to pool and foam in the crankcase, if the blow-by gasses cannot
send it to the external cooler and tank. There's even a little O-ring
to seal the attach bolt, which is easy to lose or damage. Thus the
importance of having a manual, but not just for torque values, as here
the torque is the same as any generic M6 bolt.
Rotax does not specify a Loctite for this bolt. It's easy to remove
oil from the bolt, but not the oily threads in the boss on the head.
I don't think there's any Loctite'd bolt inside the engine where oil
abounds, as Loctite could be effective except when assembled new.
Safety wire I'm sure would be, but ineffective if over-torqued to near
failure. It's also easy to periodically check the torque with a
simple metric Allen wrench. Had there been any failures not related
to improper maintenance, I think there would be an SB by now?
Regards,
Fred F.
Roger Mills wrote:
>
> Mark,
> You're right, I didn't read it properly - when he said it "worked loose" I
> assumed the bolt unscrewed itself (although it probably did). It still may
> be worth wire locking to get a slight improvement in reliability - but the
> fundamental solution I guess is the correct torque and locking compound!
> Under the circumstances, perhaps the LAST thing anyone should do is try to
> check the tightness of their rocker cover bolts without knowledge of the
> correct torque setting!
> Regards
> Roger
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