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mondos829
08-09-2013, 03:07 PM
Boat is a 76 SS. My RPM's are very high when throttle is opened all the way, like 6000 rpm. Could the drive be slipping? Drive oil is topped off and does not smell burnt.

Would prop damage cause power loss and high rpm?

Would anything else cause this issue?

93Prostar190
08-09-2013, 08:10 PM
Wrong prop? Or prop slipping on shaft?

thatsmrmastercraft
08-09-2013, 11:47 PM
Have you recently changed props? If not, I would remove trans lube and install fresh stuff and see if there is a change.

strad
08-10-2013, 11:35 PM
It occurs to me that the tach could be reading wrong as well. Probably would be good to verify its accuracy.

thatsmrmastercraft
08-11-2013, 12:26 AM
Boat is a 76 SS. My RPM's are very high when throttle is opened all the way, like 6000 rpm. Could the drive be slipping? Drive oil is topped off and does not smell burnt.

Would prop damage cause power loss and high rpm?

Would anything else cause this issue?

Yes, is your prop damaged?

strad
08-11-2013, 06:49 PM
Yes, is your prop damaged?

Lol I'd like to see the type of damage that would result in an overrev like that! On a side not it amazes me how many damaged props I see, and people are running them as if nothing is wrong with doing that.

mikeg205
08-11-2013, 06:50 PM
Lol I'd like to see the type of damage that would result in an overrev like that! On a side not it amazes me how many damaged props I see, and people are running them as if nothing is wrong with doing that.

^^^^ I know right??? ripped up props and chewed up skegs... mostly on IO's.... I bet many a Tahoe dies this way....

thatsmrmastercraft
08-11-2013, 07:11 PM
Lol I'd like to see the type of damage that would result in an overrev like that! On a side not it amazes me how many damaged props I see, and people are running them as if nothing is wrong with doing that.

If blades are torn up enough, and you ignore the vibration, it doesn't take a lot of cavitation to over-rev.

mondos829
08-12-2013, 08:48 AM
Ended up being a exhaust leak. Everything is back to normal with RPM's

thatsmrmastercraft
08-12-2013, 09:34 AM
Ended up being a exhaust leak. Everything is back to normal with RPM's

Interesting source. Good to hear issue is resolved. Exhaust manifold gasket replacement?

mondos829
08-12-2013, 10:19 AM
No. Drain plugs fell out. Rusted out threads.

thatsmrmastercraft
08-12-2013, 10:23 AM
Interesting..........