2005 Excalibur 330 revs top out at 3900 RPM ????

[Redzed]

Hi,

Although ive owned boats for years, I'm new to Nautiques, so apologies if I ask any stupid Q's.

I've just purchased a 2005 SN 196, with a PCM 330 Excalibur fitted. When pulling a skier out of the hole, she seems to have plenty of power. However, the maximum RPM I can get out of her is 3900 (sometimes it tops out at 3600) with or without a skier. Sorry I don't know what speed it equates to but the speedo does not work either. With the engine in neutral, she will free rev upto the rev limiter at over 5000 rpm.

I've searched the forum but haven't found an answer. Any help would be great fully appreciated.

[NautiqueJeff]

First thing we'll need to know is which prop is on the boat.

[Redzed]

It's a 4 blade ACME but not sure what TPI.

Sorry, i probably wasnt too clear with the explanation. It's not a propping issue as the engine sometimes revs up to around 4100 but will then drop and stabilise back at which ever speed it settles at (3600 or 3900).

You can then blip the throttle and it will rise momentarily then come back down.

[skiinxs]

Buy (or borrow from somewhere like AutoZone) a fuel pressure gauge. Connect the gauge to the fuel rail and monitor pressure when you are running the boat at the rpm's where you are having the problem. It should hold around 60psi. If it drops when the engine loses rpm's it is a fuel delivery problem. If it has full power for a few seconds, then loses pressure, I would suspect the low pressure pump and/or primary filter. (could also be a restriction or debris in the pickup screen in the tank or a restricted anti-siphon valve). If the pressure drops immediately at a certain rpm when you give it throttle, I would suspect the donut filter inside the fuel control cell and/or the high pressure pump inside the fuel control cell.
Dave

[Quinner]

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