My jaccuzi jet with 460 rattles or knocks ??

[boot]

I just put it in the water for the first time . It's a 1977 Omega . In somewhat poor shape for now . Went over everything motor wise and went for a run .It has a death rattle the harder you push it .Pretty sure it's the jet . It also had a rattle or knocking sound on the trailer when running . I thought it was just no water in the jet . I know nothing about these things . Where do I start ? What could it be ? And about how much could it cost for parts? I can do the work ,just not farmiliar with jets . THank you for any help, JOE

[CoastGuardSteve]

Try and avoid running it on the trailer unless you have disconnected the jet from the engine. Some say it's okay if you have a good water supply, others say no way. I don't run mine on the trailer because I want my jet to be good'n'tight for as long as possible. Your paying the bill so you will have to do what works for you though.
Happy boating,
Steve

[boot]

Yeah ,I didn't think it was good for it either . But it rattles in the water when under load . Is it just bearings or something more $$$??

[oneultrarat]

could be your u-joints between the engine and jet drive?

[WetNwild]

Hay boot, I just bought a 77 omega about 2 months ago with a 460-jaccuzi. I got it cheap $1700.00, new it was in poor shape, but found out it was in worse shape than thought. I think you need to isolate the noise first, I use a cheap stethoscope to find out where its loudest.

[77charger]

i'd go with the u joints i had a bad one on mine and it shook as the rpms picked up so did the shaking!
If not inspect bearings in the pump and be sure shaft is strait

[79Hawaiian]

I had bad ujoints on mine when I first bought it. I also have 460 with Jacuzzi although it really doesn't matter what you are running, u-joints need packing. I don't think the previous owner knew they could be greased.
FYI, mine still knocks when on the trailer but only at idle. I found it was the solid motor mounts. Im running a mild cam and the motor wants to bounce a bit at idle. Since there is no rubber in my mounts they make some noise. Once the boat is in the water the knocking goes away as the vibrations are released into the water. Took me some time to figure that one out.

[boot]

THanks guys ! I put new U joints in before I took it out . Mounts are new .(Rubber) MAybe have to tke jet apart ........

[TripleThreat]

I had/have the same problem with my 20ft Bayon miniday. I just bought the boat and it also had a very BAD vibration, so I took an had the driveline balanced. That took care of a huge amount of the problem but I still get a vibration at low RPM's that is bugging the hell out of me! I think next winter I will take the pump apart and have the shaft checked for straightness.
Jay

[Hollis]

Mine raddled when the oil got low...either in the bowl or the 460.