I have never owner any of these engines .... but I have been reserching inboard diesel for years ...as I will eventualy have a rib with 1 or 2 of them .........
A lot of guys complain about the turbo lag in the Yanmars ... especaly the 315.... 24 valve unit because the engine is working on its limit of HP output ....... but the yamaha 240hp dont seen to suffer that problem, cause of the smaller turbo to spool up etc.
The bravo 3 legs are a time bomb on the 315hp yammar and pretty much go bang within 250hrs ... but bravo 3's will seem to happly take V8 800hp petrol with no real disasters ....... ????????
Tom In redbay was telling me last week that that the put 900hrs on his yamaha leg before one of them went pop!!! and since he has fitted transom showers ... he has not killed a leg since ..... he is second only to the MOD for fitting yamaha engines and legs ....... he is currently testing legs and engines for yamaha, and the breif he was given was to break them !!!! he is not allowed to change oil or filters for 500hrs !!!! and he drives his boat a one throttle setting only ..... 100% power 100% of the time !!!!!!
My experance of Volvo is that they are well built well designed and very reliable....But expensive to repair ........ and the 6 cylinder engine has all its fuel injector pipes going over the rocker cover so when you have to check valve clearences you have to basicly remove the fuel system !!!!
so a simple 2 hour job turns into all day stint !!!
The Yamaha and the Yanmar are the same engine ...... except for turbo sizes and injector sizes in different horespowers ...... I think Mercruser use the same engine too... but only 250 hp in diesel ..... but I am not 100% on that.