Lack of Power

[STIRNINJA]

Hi All
I have a Sea ray 190cc 2000 with a 4.3 V6 Mercruiser that does not accellarate , Im sure you have read things like this before but im at my whits end . the engine starts on the button and sounds as sweet as a nut but she does not accellartate and tops out at 30mph . Im looking for any ideas can you help ??


Colin

 

[Quint4]

Here are some things to check ( not all may apply to your boat).


1. Fuel condition. Type and Octane possibly old fuel
.
2. Propeller pitch or diameter, damaged blades.

3. Restricted fuel pickup tube or anti siphon valve.

4. Crankcase oil volume, high oil level can cause aerated oil and lifter collapse.

5. Marine growth on hull and outdrive.

6. Wrong gear ratio in outdrive.

7. Restricted carburetor air intake (clogged flame arrestor?).

8. Restricted exhaust system (broken exhaust shutters/flappers) in engine transom shield or drive.

9. Poor cylinder compression ...do a compression test.

10. Carburetor defective, or wrong type.

11.Problem with Fuel pump pressure and vacuum

12. Boat overloaded, improperly loaded, or improperly trimmed.

13. Engine Overheating

14. Engine timing or ignition system problem.

15. Remote control cables and linkage for proper travel to open throttle plates fully.

16. Spark plugs fouled?

 

[lope4946]

I had the exact same problem on one of my 4.3's and it turned out to be a clogged anti syphon valve for the fuel line. I believe this valve is located on top of the fuel tank. My mechanic took the valve off and cleaned it and it works great now.

 

[STIRNINJA]

thanks Guys
Lots to be looking
many thanks will let you know how i get on

 

[Jimmy Buoy]

Banana in the tail pipe? :grin:

 

[Gunn]

5. Marine growth on hull and outdrive.

Obviously it is accelerating...otherwise you'd only be moving as fast as the current would allow. :huh:

Is your boat kept in the water? IF so, #5 could be key. It's referred on this forum often.

What's your minimum RPM when at 30mph? If you push to WOT after this, what's the RPM get to...with no change in speed?