not full power

[jeicher]

Took the boat to the lake last weekend. it was the first time i have had this boat out since i bought it. i did a major tune-up before we went. new plugs, plug wires, fuel line, oil change, oil filter, fuel/water seperator, and i added a inline fuel filter. it ran great for the first 2 hours, while pulling a tube. Then after the first 2 hours the boat wouldn't run over 1500 rpm in gear. if i put the boat in neutral it will rev all the way up. once in gear it acts "doggy." any ideas of what i could try?

thanks.

 

[QC]

Re: not full power

OK, so new to you, right? What about the fuel in the tank? I'd start with checking/changing the fuel filters again. Maybe some crud in the tank, water, old fuel? Revving in neutral really doesn't mean much, best to avoid.

BTW, welcome aboard!!

 

[jeicher]

Re: not full power

i replaced the inline filter i added and the fuel water seperator. inline wasn't plugged and seperator looked good. i went back to the lake yesterday and same problem. i filled the boat with fresh fuel. and even add heet to help treat the fuel. just at a loss for what to do.

 

[Don S]

Re: not full power

Just a couple of minor questions, like what engine, what drive, what year?

 

[QC]

Re: not full power

Did it run well for a while the second time to the lake? Or stuck at 1500 RPM in gear the whole time on the 2nd trip?

Are you getting full throttle at the engine? Maybe a cable stretched. Start again with basics despite what you have already changed. You had it right (good), you'll get there again.

Info on your package? Year, model, engine model, hp, drive etc. etc. More info is always better.

 

[jeicher]

Re: not full power

the boat is a 1989 four winns 170 freedom. Has a 2.3l inline ford motor with a omc cobra stern drive.

the second time at the lake it would only go up to 1500-1600 rom still. once in the water the boat runs fine. but trying to "open her up" it speeds up fine til the 1500 rpm.... in neutal i can idle and rev up fine. its only under a load it acts up.

 

[Don S]

Re: not full power

Revving it up in neutral is a waste of time and tells you nothing.
Just as a quick test, I would hook up a remote fuel tank (an outboard tank) directly the the engines fuel pump and see how it runs.

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

Some of the items you know are ok since it ran good for a while. Just disregard those items.

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.

 

[QC]

Re: not full power

Forget the stretched cable. Brain cramp.

 

[newfie12]

Re: not full power

Had the same problem with my boat, Completely drained all the gas and refilled with supreme gas. Have not had a problem since.