While Yamaha "dappled" a little in F1, they were never going to put in the amount of effort that Renault, Ferarri, Merc is putting in. They do not have the resources.
Sorry Dan, here is the real Answer from Wikipedia
Formula One
Yamaha as a Formula One engine manufacturer
Formula One World Championship career
First entry 1989 Brazilian Grand Prix
Last entry 1997 European Grand Prix
Races entered 130 (116 starts)
Chassis Zakspeed, Brabham, Jordan, Tyrrell, Arrows
Constructors' Championships 0
Drivers'
Championships 0
Race victories 0
Podiums 2
Points 36
Pole positions 0
Fastest laps 0
Yamaha produced Formula One engines from 1989 to 1997, initially for the Zakspeed team, in 1991 for the Brabham BT60Y, in 1992 for the Jordan 192, from 1993 to 1996 for Tyrrell, and in 1997 for the Arrows A18. These never won a race, but drivers including Damon Hill, Ukyo Katayama, Mark Blundell and Mika Salo scored some acceptable results with them. However their engines were often unreliable and were usually regarded as not very powerful.