I have a D2-40 sitting in the cockpit
for me to install - 'hope I don't have this problem. Do keep us informed.
I think the primer/fuel pump is a Racor
part, so if you are out of warranty you might start buying replacements
there for a lot lower price
. I plan on doing what I have done for 3 decades: put an outboard
squeeze bulb in the fuel line before the off-engine prefilters. This makes it easy to change filters and top up the fuel, as well as bleed the engine. If the primer pump on the engine becomes a problem I would replace it with a filter without the pump. I don't like the Volvo
part as there is no drain for water
, although the prefilters should have dealt with that anyway. I would prefer a permanent metal bowl with replaceable element, drain, and no pump.
How far below the engine is the bottom of the tank? The spec for this engine is 0.8m (31.5") to the feed pump inlet on the engine - beyond that you can expect to draw air into the system. The solution is to either use a day tank, and a transfer pump for fuel in lower tanks
to put the fuel in the day tank, or add an electric
pump (with adequate suction and capacity) on top of the tank. I use a day tank, which solved
air problems with the old engine. Either way, the fuel lines/filters/pumps will not have a high suction; no matter how well everything is sealed together, high suction will draw air in at some point.
Other than that I don't have anything to offer - perhaps once I am up and running I will have some ideas.
Good luck. Greg