Back to your original question for a moment, but first some background, I just bought a twin engine 99 Sportster 1800 (18 ft 7 passenger twin 717's), part of reason I went with a twin engine boat is that I have been stuck out on a river overnight in a boat with engine problems with the mosquitos and aligators all night, it was not fun. (engine goes out an hour before sunset and a mile and a half or so to the nearest boat ramp in an unpopulated area, you think someone will be along any time, you have been seeing people in other boats all day, but no one shows up....)
My point is a looked into the subject on these boats and there are failure modes that do take out both engines, running out of fuel is of course one, and there is only a single fuel tank, there is also at least in stock form only a single battery, and you never know when a battery may have an internal short and go dead. For the most part the setup is a pair of PWC engines, however they do share a common MPEM engine controller which likely has the DESS security system so you must have a working DESS post for the security lanyard or else the MPEM will not allow the engine to start.
At least that is the case on the 787 powered Speedster as the MPEM controls variable timing on the engine, one of the advantages of the slightly older design 717 is fixed timing, which makes it in theory posssible to bypass the MPEM and hot wire the engine, something I considered vs a night with the wildlife....
Ike
p.s. also remember anyone can take a boat to a detail shop and maybe some touching up of the upholstery and get good low res photos. The boat I just bought for $2,200 (with engine trouble) looks fairly good from 20 feet away, but a less good from 5 ft away, but I am working on that.
