Dual Bravos...same clanking noise???
#21
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Are you saying engine cam overlap? That is curious because I have just reduced the engine idle rpms to reduce stern drive engagement stress. The warm engines would hover about 1,000-1,100 rpms and I reduced that to ~750 rpms. I wonder if this is a new/induced vibration/noise due to that.
I have been warned about reveberation, so I may bump them back closer to 850...and maybe solve the issue.
KEEP THE INPUTS COMING... I take them all in and am getting a lot of good advise/experience.
I have been warned about reveberation, so I may bump them back closer to 850...and maybe solve the issue.
KEEP THE INPUTS COMING... I take them all in and am getting a lot of good advise/experience.
850rpms in neutral is fine for bravo drives.
#22
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FWIW, my Bravos behind my unmodified 6.2's idling at a measly 600 rpm have always clattered and had a minor vibration (as you describe) according to my ears on the muffs.
IMO, it's due to no load being on the props.
Run em until they quit.
IMO, it's due to no load being on the props.
Run em until they quit.
#23
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I can actually feel the clanking on the top observation plate / Drive showers... but I will bump the RPMs a little bit and see if that helps. Should be reunited with the boat in about a week.
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Last edited by F14A water jet; 06-28-2021 at 07:45 PM.
#28
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Okay, new information. I bumped my idle up to 850/900 on one motor and the noise got significantly diminished. I can still "feel" some slop but I do not hear it as much. A local boat mech. visited and thought the drives were still a little loud (he also believes the drive shower caps might amplify the sound). Unfortunately, the noise in the drives is drowned out by the un-muffled exhaust :-)
So we pulled the observation cover on the port drive. Recall that I just did a fluid change and there was virtually no metal/hairs on the magnets and both drives looked identical.
I understand these drives were "worked on/freshened up" about 50-60 hours ago to accommodate 600hp motors.
(See Videos/pictures)
1) Is this too much "slop/play" in the top gear?
2) Should I add additional shim/spacer to the top ring (see picture below) to reduce the slop/play?
3) When I replace the top observation cover, do I need to do anything (gasket sealer?) for the O-ring...it looks to be in excellent shape (are they re-usable)?
THANKS!!!
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So we pulled the observation cover on the port drive. Recall that I just did a fluid change and there was virtually no metal/hairs on the magnets and both drives looked identical.
I understand these drives were "worked on/freshened up" about 50-60 hours ago to accommodate 600hp motors.
(See Videos/pictures)
1) Is this too much "slop/play" in the top gear?
3) When I replace the top observation cover, do I need to do anything (gasket sealer?) for the O-ring...it looks to be in excellent shape (are they re-usable)?
THANKS!!!
![](https://cimg8.ibsrv.net/gimg/www.offshoreonly.com-vbulletin/2000x1504/0628211609_5d11893ff178ce038b15a5b4c566d47d8bbb1b41.jpg)
#29
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You’ve removed what holds the clutch shaft and gear in place, it’s going to wobble around like it does in the video, put the top cap back on and remove the back cover and you’ll see that it moves very little
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F-2 Speedy (06-28-2021)
#30
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