Speedster cavitation, bogging and fuel

[shawkat]

Good day
I'm new here at the site and my first post

I'm having few problems with my 2007 speedster 150 SCIC.
Cavitation, bogging and consuming fuel.

I bought the boat from a friend of mine, 110 hours on the clock, I took it to the dealer for full service, and have replaced some parts, like steering and throttle cables, fuel filter, wear ring, etc.
I went for a test drive and the boat wouldn't go higher than 6500 rpm.
So I took it back to the dealer,
They have replaced the air intake with riva air intake, and sealed the ride plate, new engine mounts and a new grate intake.
I took it for a quick test drive, it was impressive, 7,400 rpm 51 MPR, it was a very hot day 110 degrees, water temp 99, I was satisfied,
The following weekend, i refueled (almost full tank) the boat and went for a near by island 6 miles away, 4 people on the boat and a full icebox.
7100 rpm, speed 40-43 MPR,
When I reached the Iceland, I took a normal left turn, all a sudden the boat started cavitation, and white smoke, it wouldn't move at all, no alarms was going off, so I reached the the beach at idle, turned of the engine, couples of hours later I started the engine planning to drive at idle to find someone to tow us back , and gradually the boat started to speed up, I went back to my friends, picked them up and went back to the marina, however the boat bogs when turning left or right and when hitting full throttle quickly, and to my surprise, we reached the marina with an empty fuel tank .
I took it to the dealer and I still didn't hear from them yet.

Any idea what's going on with the boat?

Appreciate any replies
Thanks

 

[KK40384]

Sounds like you have something sucked up in your pump. It's small enough to where you can gradually plane out but can't accelerate hard. I bet on your way back you were turning high rpm and the SC was working hard and drinking extra fuel due to the cavitation.

 

[shawkat]

Thanks for the reply.

I’m sorry i forgot to mention, when the boat started to gradually speed up, the cavitation was gone, i stopped and accelerated again, it was fine, no cavitation at all, like it was never there, same top speed same high rpm, however the bogging remained at full throttle and when turning the left or right the rpm would fall.

Thanks

 

[pwgsx]

When was the S/C last rebuilt?

 

[shawkat]

I was told that I was rebuilt at 90 hours,

 

[Coastiejoe]

Almost sounds like you sucked something causing cavitation as well as an over heat. Once you shut it down the item fell from the intake. This fi zed the cavitation and performance issue but left an over heated engine.
How far was the beach from where you had the issue?

Even at idle our engines needs plenty of water to keep them cool.

 

[shawkat]

Thanks for the reply,
I'm also guessing an overheat problem, but why the alarm didnt go off?
Does a heated engine bog while turning left or right? Or at WOT? What about the white smoke? And the excess fuel consumption?
From where the problem happened to the beach was around 3 mins at idle.

 

[Coastiejoe]

Thanks for the reply,
I'm also guessing an overheat problem, but why the alarm didnt go off?
Does a heated engine bog while turning left or right? Or at WOT? What about the white smoke? And the excess fuel consumption?
From where the problem happened to the beach was around 3 mins at idle.

Boat engines work harder anytime they are in a turn. Has to do with lateral force and pushing water sideways to allow for the turn. Unlike cars, boats steer from the stern. So if you turn left you are actually pushing the stern to the right. The stern is in the water as compared to being on the water. Thus you push water out of the way to turn the boat.

White smoke is normally a sign of a cracked head or bad head gasket.

Can't give a definite answer as to why no alarm. But could be defective sensor or maybe the beeper is inop.

Also, there is an item called a GUARDIAN on Seadoo boats. This box does a few things. One of which is to increase engine RPMs when the wheel is cranked all the way over. I'm not positive what boats the Guardian is on. Sure there is a begun date for example.
[MENTION=16022]Dr Honda[/MENTION] can clarify this.

3 minutes even at idle in an already up to temperature engine is enough to do damage I would think.

.

 

[ken0276]

My 155 hp 08 speedster revs 7260 rpm for 51-52 mph top speed with one person in the boat, with 4 person in the boat, if they weighted 300 lb each one, that will definitely make the engine work harder and slow down the boat a lot.