Hers's the skinny Crazyboat, I used to be apart of a jetski race team way back in the day. I have been around these skis my entire life. I have built many jet jon's to date as well. The ski that I used to build this jon (2000 Kawasaki ultra 150) was the fastest production 2stroke PWC of its time. Its a true 65, 66 mph ski in stock form. Don't know where your numbers of 53mph are coming from. I actually own another Ultra 150 that I can confirm those numbers plus if you google Ultra 150's those mph numbers are all over the net. Also the ultra's weight comes in around 600lbs and my boat is weighing in at 790 when we rolled it over the scales a couple of months ago. So yes, I have more drag (regardless if the hull is bare or painted) and yes it does weigh more. So, After it's all said and done, mid to upper 40's is actually quite well. The main reason for painting is I had to patch so many rivets that already had stress cracks running from them, plus patch large holes that had been punctured in the bottom. That boat had been abused by the previous owner and I was left with alot of work needles to say. So, I wanted to cover all the ugliness up because I was painting the whole boat. People always are surprised when I tell them that at wide open speeds in the boat is just as stable as if it was at 15mph. I had a 14/32 jon with an 80hp waveraider engine in it that would hit 43, and it was super smooth and stable. But the objective of building these boats with greater horsepower isn't for the top speed, it's so the the cruise speed can be moderate at lower rpm and also to be able to carry gear and passenger's with out the engine struggling all the time.
Sorry, don't know where I got this from but for some reason I was thinking you had the engine from a Yamaha ski, the same model as a friend of mine had that topped out at 53 MPH on a GPS. So yes, my numbers would be wrong. Still if you got 65+ from a 150 HP engine that's pretty fast, many 250 HP ebgines ran stock at about 70 as I recall, no? (Yamaha/Seadoo)
You are correct about the 250 hp skis. But keep in mind that the federal government has a speed leash on the manufactures. Stock skis can't exceed 68mph from the factory. Now we all know that they are capable of much greater speeds with an aftermarket tune and so on. A good friend of mine has an 08 kawasaki ultra 250 (250hp) me on my Ultra 150 and him on his from a dead stop he blows the doors off of me out of the hole and I cant catch him but when we do a 30mph kick, we are handle bar to handle bar all the way to top end and over a half mile he may pull ahead one ski lenght. That's how impressive the older Ultra 150's were.
Crazyboat said:
I didn't read every post in this thread and am not sure why other then a leak in the rivets you didn't leave the original aluminum bottom but that hull does sound like it's adding tons of drag IMO. The ski it came out of (if my numbers are right) ran 53+ and it a god amount heavier then your jon, granted you have more hull touching for drag (wider).
Either way she's a nice looking boat and as mentioned anything above 40 in a light boat can get tricky with wind and a wave or two.
Enjoy and run hard!