Do I have a motor problem

[finsh'n'freak]

I have a 2008 150VMAX with a 23P tempest prop. I can only turn prop about 5200 RPM's at full trim for about 52 MPH. Ive tried everything to get more RPM's and speed and I just cant do it. Im starting to wonder if my motor is down a cylinder. The problem is this is the most RPM's I have been able to get since I bought it from the dealer a few years ago. Compression and plugs are good. Im going to change my water separating filter and see if that helps anything. I see other 150 motors turning 5600-5800 RPM's and Im not sure why I cant.

[BASS BUM]

Have you tried a smaller pitch prop?

[finsh'n'freak]

No, Im sure the smaller pitch would increase my RPMs but it wouldnt do much for speed would it? I see the same motor turning the same size prop 5800 RPMs.

[JoeFriday]

If compression and plugs are good, that would likely mean you are not down a cylinder. What hull and what is your prop to pad? There are many, many factors outside of the motor itself that could impact performance. While it could be motor related, it sounds like it could be somewhat from set-up.

[ruppbm15]

Do you have a hotfoot? Are you positive you are getting full throttle? Check the backing screw where the foot pedal hits

[CatFan]

How big of a prop you can turn depends on both the engine and the hull. What boat is this on?

[finsh'n'freak]

2008 Stratos 285xl

I have not checked the full throttle. Is it possible to adjust the screw behind the hot foot to far?

[rat0502]

2008 Stratos 285xl

I have not checked the full throttle. Is it possible to adjust the screw behind the hot foot to far?

Just recently, I found 500 rpm's on mine. Between a missing screw on the throttle linkage and a mis adjusted throttle cam and hot foot, it made an incredible difference.

[BASS BUM]

No, Im sure the smaller pitch would increase my RPMs but it wouldnt do much for speed would it? I see the same motor turning the same size prop 5800 RPMs.

. Are you comparing the same boat and motor set up? If not more rpms should get you more into the power band with more speed. You may want to talk to one of the prop guru's like mark croxton from marks props or Todd at hydromotive. They deal with these problems all the time and may give you advice on how to tweak your prop or suggestions on something different. If you don't find anything mechanically wrong with your set up.

[Charles Prestridge]

Keep looking at the basic items like mentioned above.

Have you checked fuel pumps to make sure they are not leaking?

[champ210]

Take it over to Malones Marine. Talk to Jeff. He is prob one of the best Yamaha techs I our area

[finsh'n'freak]

If I cant figure it out that will be my plan. Ill have to wait until summer when I have a few extra $$$.