Re: OMC 5.7 L 15 x 11 pitch prop

[billsmith]

Re: OMC 5.7 L 15 x 11 pitch prop

This is an old post I came across but it fits my issue

I have a similar issue my boat is a 27' Bayliner (LOA 30') and about 6000lbs I am currently running a 13pitch 15.5" and I only gets up to maybe 4000 rpm WOT

The 15 pitch I used to run had a hard time getting on plane... The 13 pitch is better but wont plane if I have more than 6 on board.


Any help would be appreciated

Bill....

 

[jestor68]

Re: OMC 5.7 L 15 x 11 pitch prop

Re: OMC 5.7 L 15 x 11 pitch prop

It appears that you don't have much choice but to reduce pitch to the 11 pitch prop; which appears to be the lowest pitch available.

Are we to assume that you too have the OMC stern drive? What year is it?

 

[steelespike]

Re: OMC 5.7 L 15 x 11 pitch prop

Re: OMC 5.7 L 15 x 11 pitch prop

It appears you have something more than prop selection going on.
I would suspect the motor may have an issue(s) I would start with a compression check.
You should be sure it is in excellent tune.Timing set right and advancing as it should.
Be sure the throttle opens all the way.
I'm guessing it would normally run a 15" or 17" prop possibly even higher.Speed 30-35.

 

[dazk14]

Re: OMC 5.7 L 15 x 11 pitch prop

Re: OMC 5.7 L 15 x 11 pitch prop

It appears you have something more than prop selection going on.
I would suspect the motor may have an issue(s) I would start with a compression check.
You should be sure it is in excellent tune.Timing set right and advancing as it should.
Be sure the throttle opens all the way.
I'm guessing it would normally run a 15" or 17" prop possibly even higher.Speed 30-35.

+1. Has anyone touched the base timing? Of course, if it is no longer advancing the timing, that would equate to a substantial power loss.

When you get it right, switch to a 4 blade - if one is available.

 

[Bondo]

Re: OMC 5.7 L 15 x 11 pitch prop

Re: OMC 5.7 L 15 x 11 pitch prop

It appears you have something more than prop selection going on.
I would suspect the motor may have an issue(s) I would start with a compression check.
You should be sure it is in excellent tune.Timing set right and advancing as it should.
Be sure the throttle opens all the way.
I'm guessing it would normally run a 15" or 17" prop possibly even higher.Speed 30-35.

Ayuh,.... Might wanta go through this list of Don'S,....

Here is a list of possible causes of low WOT (Wide Open Throttle) rpm.

In no particular order

Engine Won't Reach Operating RPM. Check

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 Fuel System Test
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 Compression Test
10. Carburetor defective, or wrong type.
11. Fuel pump pressure and vacuum
12. Boat overloaded, improperly loaded, or improperly trimmed.
13. Engine Overheating
14. Engine timing and ignition system operation
15. Remote control cables and linkage for proper travel to open throttle plates fully.