4.3 trouble

[wildcat]

hi guys i have a bayliner that i just put a new motor in 4.3 it runs fine in the water till you put it in gear it wont run more than 1800 rpm in gear you take it out and the rpm will race up to 5500 in neutral motor sounds great i am stumped its a 1992 4 bbr carb what can it be?

 

[chiefalen]

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.
__________________
Don S.

Copied and pasted here from another web site.

Good info if correct and accurate should be shared no matter what the source HAH.