William Daniell a crit :
> My motor starts fine the pressure goes up to 5.5 bar for about 2-4
> minutes.
>
> It then falls with not loss of rpm to 1.5 bar for about 2-5 minutes.
>
> It then goes back up to 5.5 and stays there without a problem.
>
> The oil pressure sender is working fine and is the gauge I have
> tested them both. The engine runs smooth and produces sufficient
> power. I run avgas because the premium mogas here is 95 or lower octane.
>
> On a hot day the pressure drop is minimal on start up. So I am
> thinking that maybe this has something to do with viscosity. Perhaps
> even what Ira mentioned - lead accumulation in the oil tank.
>
> Any ideas as to the cause?
>
> How much damage will this do? Clearly this is not ideal but it could
> be one of those problems where the solution ends up being always out
> of reach.
William,
If your engine is a Rotax 91X, then you might wish to review the SB on
oil starvation on startup.
Yes it may have something to do with viscosity when cold, and oil pump
starvation due to length/diameter/routing/obstruction of oil line.
Especially as you seem to say that the problem is less obvious on a hot day.
FWIW,
Regards,
Gilles
http://contrails.free.fr
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