Re: Mercury Jet or Yamaha Jet
Before you get either motor, what size and type of hull do you have, plus how many people do you plan on having in the boat. The last thing you want to do is under power a jet boat. I've use Yamaha, Merc and Evinrude jets.
I see more Mercs than any thing else, mostly because they cost less, but the owners like them. Yamahas cost more and the owners love them, a friend of mine keeps his jet boat at my dock and I use it frequently. He has a Yamaha 60/40 2 stroke on it and I must say it is a pleasure to use, quiet, good power and starts easlily. It's on a 16' G3 aluminum hull and it's a great combination for 2 people, three is OK but the extra weight really saps the power and speed. I have 90/60 Evinrude and it works great, but is much louder than the Yamaha and is a little harder to start, it's not bad, it's just that the Yamaha starts so easy.
Most of the four stroke jets are quieter than the 2 stroke models, but the four strokes don't appear to be as good at getting on plane and the top speed may be a little less.
I also think that the 30% loss of power between a prop and jet is a little optimistic, I've use the same motor with each on the same hull and it seams more like 50%. My friends G3 would fly with a 40HP prop on it, but with a 60/40 pump it's just adequate, same with my boat.
