Just had a new prop shaft installed by my marina. I'm concerned a new packing flange is too tight. It doesn't leak a drop of seawater and I noticed my RPMs have dropped from a max of 2100 down to 1800. I also noticed I reach max operating temperature of 180f fairly quickly. I tried to turn the shaft unsuccessfully by hand in neutral. I will feel the shaft for friction heat after running the diesel for about 30 min today. That will tell for sure if the flange is too tight. Your thoughts?
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Joe Lucido
1986 Catalina 36
Hull # 0625
M-25 Universal diesel
Oceanside, CA
Joe,
I think one of the first things you should do is adjust your tach. You should be able to reach about 3000 RPM at WOT (wide open throttle). Boat tachs are notoriously inaccurate. There are lots of posts on how to do this. What kind of packing material did the marina install? With no drips at all, most likely the packing nut is too tight, but we need more details to comment accurately. And, you should be able to turn the shaft by hand when the tranny is in neutral.
Tom Sokoloski
C36/375IA Past Commodore
Noank, CT
The marina loosened the flange and seems ok now. They showed me how to adjust as needed. Curious about the tach though....How it could be so far off. I believe the alternator activates it.
Joe Lucido
1986 Catalina 36
Hull # 0625
M-25 Universal diesel
Oceanside, CA
Joe,
One the best pieces of equipment I have on my boat is a laser temperature gun. I recommend you get one and shoot that prop shaft to get some temperature data. Your marina could have used some dripless prop shaft sealer, but I'd sleep a lot better if I knew what the cold and operating temperature of that shaft is.
If that shaft is running hot, the marina can do the repacking over again.
Bill Matley
Duncan Bay Boat Club
Cheboygan, Michigan
Lakes Huron, Michigan,
Canadian North Channel
"Spirit of Aloha" Hull #1252
Laser temp reader is a great idea. Have one in my shed. The marina loosened the flang and seems ok now. They showed me how to adjust as needed.
Joe Lucido
1986 Catalina 36
Hull # 0625
M-25 Universal diesel
Oceanside, CA
Hi Joe,
I have an electronic/digital photo tachometer you can check your boats tachometer with. We are just down the street from you in the Oceanside harbor. It is an easy process. There might be an adjustment on the back of your engine panel to correct your indication.
Not sure when I'll be down to the marina, but I will be down there some time this week. Send me a note and I will get the Tach to you. Glad you got your bearing settled.
P.
Paul O,
S/V Pelican
1989 Catalina 36 Mk I #894
Oceanside, California