Hi Richard,
We have an XS with a 912S and the Skydrive carb heat (hot water). We
have had the engine run rough both on the ground and in the air, both
cured within less than a minute after carb heat is turned on (usually
after 10-15 seconds). We don't leave the carb heat on all the time
because it raises the hot start temperatures, although it doesn't hurt
performance when on (we have carefully checked this). In the air we
have had carb ice at normal cruise and when throttling back. The carb
temp gauge (supplied with the carb heat kit) indicates a few degrees
---From 0 deg C whenever we have seen this carb ice condition.
We have also had the engine run rough due to what we believe is vapor
lock. This has only happened in the winter time (when there are more
volatiles in the auto gas), after a hot start, and typically after
taking off from a higher altitude field. We have since added more
insulation in the carb and fuel line areas, protecting them from the
exhaust 'hot spots'.
regards,
Terry Seaver
A135 / N135TD
Richard Holder wrote:
>Richard
>
>The air pressure must be equal in the tube and the intake. I think your
>"Ts" are OK.
>
>Have you considered icing? Do you have carb heat? I have the hot water
>type. It works fine, if I turn it on. If not, runs rough at the end of a
>fast clime out.
>
>Good luck.
>Cliff Shaw
>1041 Euclid ave.
>Edmonds WA 98020
>(425) 776-5555
>N229WC "Wile E Coyote"
>
>
I don't have the carb ice kit.
Carb icing is a possibility for the once-every-20-minutes misfire (which for
now I can live with !)
When you say it runs rough at the end of a fast climb out do you mean
immediately you level off and reduce power ? Or after a minute or two or
five ? And if it runs rough like that does it go away after a certain length
of time if you don't put carb heat on ?
I am contemplating putting the same kit on, but before spending $340 on it I
want to be sure that the problem will be fixed by it !
TIA
Richard
Richard F.W. Holder 01279 842804 (POTS)
Bell House, Bell Lane, 01279 842942 (fax)
Widford, Ware, Herts, 07860 367423 (mobile)
SG12 8SH email : rholder@avnet.co.uk
Europa Classic Tri-gear : G-OWWW, EGSG (Stapleford)
PA-28-181 : Piper Archer : G-JANA, EGSG (Stapleford)
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