97 speedster one engine rattle noise

[azcrash]

Hey all, new to these boats but learning a lot from the forums.

Was having cavitation issues and so fully rebuilt the pumps (oem wear rings, bear kings, new cones, all that).

Took it back out on the lake and it was much better but still under performing. One engine had to always be set at a higher throttle to stay straight.

Started the engines out of water one by one. The drivers side starts up and makes the awesome "wing ding ding ding" two stroke noise and the other side starts but has much more of a rattle to it. Sounds almost like rattling rocks or maybe a metal wrench bouncing around on the top of the engine. Does not have that crisp clean 2 stroke sound.

Thought maybe I did a bad job of rebuilding the pumps. Took off the pump from the "bad" engine and could freely spin it and it did not catch on anything so I think the pump is good.

Read about the carbon ring, so took that and the driveshaft totally out... Same noise. So at this point the driver side engine sounds better with a pump connected than the second engine with the driveshaft and pump removed.

I'm at a loss now, does anyone have suggestions on the next step to check? Any input is greatly appreciated.

 

[hotrodssnova]

Check the motor mounts. Also grab the engine and see if you can move it. It should not move freely. I know that the pump will have a slight rattle sound out of the water.

 

[howie099]

One throttle more than then other is common don't worry about that. That is why there are 2 of them.

Well it can't be an internal engine part bad or the engine would be bad by now.

I would check the exhaust and motor mounts. You can make sure the anti rattle setup is good in nose cone also of the pump

 

[Danosll]

not sure if 97 was 787 or 720 .but could be rave valve(s) worn housings and or valve. (if you have them)

 

[azcrash]

Thanks for the feedback. I'll check the exhaust and motor mounts tomorrow or Friday. Wife's battery in her car died so getting that replaced is now the number one priority lol.

I know it's not the pump/anti rattle assembly because the entire pump and driveshaft has been removed. Noise still persists.

Howie099 I hope your right about no internal parts being bad, that is gonna keep me off the lake this summer if I need a new engine. Praying it's just mounts.

So there are no bearings in the engine assembly that could be going bad? The noise really sounds like a bearing issue. If mounts check out, would uploading some audio help?

Thanks again.