Prop help for a 38 zr
07-29-2011, 02:00 PM
#34
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That's the usual, probably not related to the prop though. If the other drive has the same hours on it, you might really want to think hard about tearing it apart too and replacing the upper gear. The gear is expensive (~$1500?), but it's a lot cheaper to catch it before it goes than to have to replace the entire upper. 
GL!
GL!
07-29-2011, 02:15 PM
#35
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BTW, you might want to look into this if you're planning on keeping the boat or really running it...
http://www.offshoreonly.com/forums/g...-question.html
http://www.offshoreonly.com/forums/g...-question.html
07-29-2011, 02:45 PM
#36
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you need to cut out the caged roller bearing that comes with the gear set and replace it with a larger roller bearing(torington). use the same snap ring to hold the bearing in. doing this will take the rock out of the upper gear set. That is coming from a guy that blew a lot of uppers because of mercs screwed up design from the factory.
07-31-2011, 06:55 AM
#37
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friend of mine just bought a new 38zr with 525's & it came with 34 maximus wheels. we ran it yesterday full of fuel & all it would run was 82 but rpm was 5000 with the trim set on 3. way high slip numbers for 5 blades. I don't think his boat would get up with 4 blades. any thoughts?
08-02-2011, 10:49 AM
#38
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it'll bite harder with 4 blades and run the same speed but a little lower in the rpms. About 4800 to be exact. You'll be able to hang the drives out a little bit more also if you wanted to. The boat won't do more than 82-84 with a full load. You won't see the mid to upper 80's till half tanks.
08-11-2011, 04:28 PM
#39
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(over 100gals) the center of gravity changes some forcing more trim and causes overreving wasting power (watch for the rooster tail). The more gas in the tank the worse it gets. (I imagine you may have shortis and were running with about 3/4 tank)
Try running with 70 gals of gas to see if what I'm saying is BS. It won't cost you a thing. When you find it's not BS you have 2 options: 1) Run with 90 gals or less, 2) Use longer lower drives combined with new props to match (You'll dig more and can trim approprietly).
Good luck!
