Hey chaps,
For those who dont know I have a 15.5ft open light weight (300kg hull) with a 50hp 4 stroke Yamaha circa 2003\2004.
I am having problems hitting my max revs \ power.
The Yam is supposed to run at 5500 for max power (50hp@5500rpm), but I can only get it to run at 5000rpm, occasionally 5100rpm (Load = me with 35 litres of fuel, few fishing bits, 15kgs of anchors).
This will get me to 28knots and that is fast enough for me!! But am I missing out on running at the max power point of 5500rpm? Am I missing out on potential fuel consumption?
When running fast I do find if I play with the trim I hear the exhaust \ prop coimg out the water, feels like the prop is loosing grip, not sure if this is correct?
I do run a pair of 40lb smar tabs and have set them to a low setting, should I go lower on the smart tabs?
I can rev the engine out of gear to 6000rpm no probs (6000 is max revs).
Can anyone help? Do I need a slightly smaller or bigger pitched prop?
Current prop = 10 1/2" x 13" pitch
Thanks
Rob