Yamaha 4 Strokes Vs. HPDI

[jahosaphet]

Originally Posted by all star rod

I owned a 150 HPDI and I now own a 4 stroke 150 Yamaha of course. The boat I have now with the 4 stroke is 400 lbs heavier then the boat I had the HPDI on. Based on the 150 HP motors the 4 stroke is hands down better than the HPDI. My hole shot is just as good or better. I found on my HPDI I good fuel economy at 4-5K rpms as long as I was not slowing down and speeding up..ie....keeping a constant speed...A few weeks ago I took my boat to Dularge and ran 91 miles per the GPS so figured I ran 88 miles and I burned 19-20 gallons running at average of 5K rpms or 42/43 mph. Read my slogan at the bottom.....enough said. Plus your resale value is high with a 4 stroke. BTW, some boat have a better fit for a HPDI over the 4 stroke. In general, the 4 stroke is a better choice. For example, I could of got a 200 HPDI on my boat for about the same price as the 150 4 stroke (which that tells you something) and got 6-7 miles top end faster based on the Yamaha performance data on their web site which was tested on my boat (Xpress X22 Bay) with both motors. With my 4 stroke I can run 50mph top speed with a full load and my hole shot is excellent...Those two things sealed the deal with me getting a 4 stroke.

yea the reason the price is diferant is because you have to add a camshaft, valves, and many many other things and the motor has to be bigger to produce the same power as a 2 stroke, price does not make the motor better