Small vibration, rattling noise. Any ideas?

tank1949

Lieutenant Commander
Joined
Apr 4, 2013
Messages
1,911
I keep hearing about loose flywheels..... Is that a common issue with these. The mounts and transom are very solid so i don't think that is an issue. "Gimbal bearing should not move"..... Now we are onto something. With my alignment tool installed i could move the tool up down or left right with some persuasion. Is that not normal??

Push it all the way end until you hear "thump!" Then if slop moving side to side or up and down, you have a problem. In addition, watch gimbal bearing to see if inside donut moves with alignment tool. It shouldn't! Also, if you replaced head gaskets, are you sure valves are correctly adjusted. With plug wires easily pulled (loosened) at distributor cap and motor running, pull wires one at a time and look for changes in motor's harmonics or rpms. If no change after a specific plug wire has been pulled, that cylinder may be your problem. Pull valve cover and readjust valve. Pray that is all it needs. Gimbal bearings are easy to replace too..
 
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ckraker

Petty Officer 2nd Class
Joined
Apr 21, 2007
Messages
140
I just torqued the rockers... That all that is required for the style heads i have. At least that's what the manual says. I'll see if i can get a video tomorrow
 

tank1949

Lieutenant Commander
Joined
Apr 4, 2013
Messages
1,911
I just torqued the rockers... That all that is required for the style heads i have. At least that's what the manual says. I'll see if i can get a video tomorrow

This aint rocket science, as others and I have implied. Pull plug wires while running and watch for drop in rpms. If OK, at least you will have eliminated something in your top rebuild that is causing issues. Remember! What have you changed? Even if boat never ran before you bought it, you still changed something (gasket). Follow what other have suggested. Good luck!
 
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