how loud should these boats be at idle

[kxracer1]

when our 255 with the 150s is at idle in the water it makes an extreamly load rumbling noise and vibration from both motors. its very noticeable even when the boat is a a couple hundred feet away. it goes away as soon as the motors gets above 2000 rpms is this normal. i dont remember the boat doing it on the test drive before we bought the boat but did it since the first time we splashed it after purchase. i have never hear another scarab run just seadoo and they dont seem to do it. they are nice and quiet

 

[ScarabMike]

Check and make sure your air filters are on tight, open the engine bay and have someone drive the boat. Check the exhaust manifolds for leaks (side of the engine). Check your cats, and make sure the hoses are connected, and your O2 sensors are in and tight. Make sure your water boxes have no leaks. If all is good, check the sound deadening foam, and make sure it hasnt come off of the hatch for panels.

 

[kxracer1]

everything is nice and tight no leaks just the one on the starboard carbon seal because the engine is mounted to far forward just waiting on an appoint to get that fixed. there us deffinintly a vibration that goes along with issue and it stop asson as any throttle is give both motors do it. next time im out i wi try and get a audio clip of the noise

 

[kxracer1]

https://www.google.com/url?sa=t&sou...AQo7QBCB8wAQ&usg=AOvVaw2C6pBzlrll_7f6isNpS-uP the vibration/rattle is very similar to this both motors do it