DF 175 not making RPM's

[youngskywalker]

Hopefully someone can help. I have twin 2008 DF 175's

The port motor is not revving beyond 3000 RPM's. This happened all of a sudden. The engine starts, idles and runs smooth. NO hesitation or misfiring. At half throttle it will hit 3000 to 3500 RPM's but if you push the throttle further you get nothing more. A few times it wouldn't go past 800 RPM's but generally it stays around 3000.

All the linkage seems to be normal and the butterfly is opening up all the way upon inspection. I cleaned the fuel filter (low pressure) which did have some water in it and drained the FVS (no water).

What is my next step? I'm not getting any alarms on the motor. Could it be a fuel pump or high pressure fuel filter? Thanks for the help.

[Moonlighter]

Possibly the neutral throttle switch on the engine. If it's broken or has gotten out of alignment the engine will still think it's in neutral and won't rev past about 3000rpm.

Switch is located on the gear linkages on the engine.

[youngskywalker]

Possibly the neutral throttle switch on the engine. If it's broken or has gotten out of alignment the engine will still think it's in neutral and won't rev past about 3000rpm.

Switch is located on the gear linkages on the engine.

Possible.. and incedently I was in there adjusting and lubing stuff before I had this problem. I'll check it.

But I thought the purpose of the neutral switch was to disarm the motor from starting if it's in gear. So it's a micro switch that's either on or off. It's on and works but I'll look further into it... thanks.

[Moonlighter]

There are two neutral switches -

- one on the throttle binnacle that prevents the motor being starter in gear.

- The second is on the engine's linkages as I described earlier and it prevents the engine being revved too much while it's in neutral.

I see you also posted about this issue on THT, but with extra/different info than you posted here. Such as evidence of water in filters.

It is helpful if you tell the full story of what has happened and what you have already found/done to address the problem and the results.

That way people don't have to guess or make suggestions based on half of the relevant facts. Very frustrating to answer a question only to then be drip fed additional information that might have been relevant.

[youngskywalker]

There are two neutral switches -

- one on the throttle binnacle that prevents the motor being starter in gear.

- The second is on the engine's linkages as I described earlier and it prevents the engine being revved too much while it's in neutral.

I see you also posted about this issue on THT, but with extra/different info than you posted here. Such as evidence of water in filters.

It is helpful if you tell the full story of what has happened and what you have already found/done to address the problem and the results.

That way people don't have to guess or make suggestions based on half of the relevant facts. Very frustrating to answer a question only to then be drip fed additional information that might have been relevant.

I'll be sure to check the switch. Visually it looks good and clicking but I'll check it with an ohm meter when I get a chance. My post on THT is a month old and since then things may have changed. Only when I bumped it today did I get any responses. Cheers.

[artdf175]

You did not mention a fuel/water filter between tank and engine- making an assumption you have one
If you have water in the engine filter pre-low pressure pump the main filter must be plugged and full of water
And yes it would be important to check the high pressure fuel pump filter