Engine Primers in P337H - Are they used ?
 

Hi Folks;
Please refer to attached picture. The two lower knobs [below the T-handles for pressure dump valves] are listed as Engine Primers in POH. No mention in any checklist. Did not use for engine start, or air-start. Aux Fuel Pump is used for priming before starting engines.

Anyone know a definite answer ? Are they for standby use if ship power lost & handprop ?! Were they disconnected per SB ?

THANKS

Use search function on this website and enter primer. There are a number of threads about this.

THANKS. Found the discussion. Thinking about removing them.

My 1978 P337H POH mentions the primers as being useful in extreme cold weather starting conditions, but IIRC no exact temps are provided.

Primers could also get one of your engines started (in a pinch) in case your electric boost pump failed.

Yes, there are other much longer threads, but this is about the gist of it.

THANKS I will check

* The same cold-weather ops POH section recommends draining the oil when leaving the the plane overnight in an extreme-cold location. Suggests storing oil in a warm location, then re-filling engine with the warm oil before start-up.

Warm oil is a good idea. If electricity is available, engine heaters may be more convenient (less messy than five+ gallons of oil)