Propeller Questions

[aznewsh]

I apologise if this is in the wrong forum, seemed the most appropriate from what i could see....<br /><br />I have a 1977 Sea Ray, 24' Cuddy Cabin with a small block chevvy/volvo 350<br /><br />I have been having problems with my boat getting up on plane with my aluminum prop which I have recently identidied as 15D X 17P LH rotation, Long hub.<br /><br />I visited a local prop store and since I wasn't able to provide WOT information, I basically asked what would be the next step down or rather a less aggressive props to make it easier for my boat to get on plane without losing too much on the top end. I would be interested to hear if other people's suggestions match up with what was suggested.<br /><br />Thanks for you time

 

[tommays]

Re: Propeller Questions

http://www.mercurymarine.com/everything_you_need_to_know_about_propellers5 <br /><br />some good reading about props<br /><br />pretty much the same thing here without your current WOT its hard to advise<br /><br />has it ever run correctly and what altitude is your boating area<br /><br />tommays

 

[aznewsh]

Re: Propeller Questions

No it has always struggled getting on plane, increase the weight at all on the boat and forget it - not going to happen - It is on Lake Powell currently 3604 ft above sea level. I am fairly new to boating and it didn't occur to me to record my WOT with the old prop, that prop has now been damaged, hense me being unable to measure the WOT now. I am currently using my spare prop which is even worse. These came with the boat and do not fit my needs at all, i suspect the previous person who owned the boat just used it by himself for fishing and never had nearly the same weight on board.

 

[aznewsh]

Re: Propeller Questions

oh, for the record - he suggested 16D x 15P<br />he felt that would get the boat out of the water easier without losing too much top end.<br /><br />Was really just looking for other opinions to see if they matched

 

[tommays]

Re: Propeller Questions

has the motor every been correctly set up for the elevation ,carb rejeted ect so its running correctly<br /><br /><br />the next step is a 15 x 15 but its allways nice if you can borrow one to test first<br /><br /><br />tommays

 

[kopy kat]

Re: Propeller Questions

I'm using a 17P Mercury SS 5 blade--it'll put my Sea Ray 210 up on plane fairly fast, and I only lost about 3 mph on top end - I'm at 6200 ft elevation.

 

[olbuddyjack]

Re: Propeller Questions

for the record - he suggested 16D x 15P<br />

Do you have enough room to swing a 16? If you do thats good advice. You'll get more grunt on the bottom but loose about 2-4 mph on the top and gain some rpms, just keep the revs under 4800.<br /><br />Did you think any about trim tabs or smart tabs?

 

[aznewsh]

Re: Propeller Questions

I have trim tabs, still don't get me there, It doesn't seem like I would have a problem with a 16" fitting, it is a volvo penta 270 outdrive??<br /><br />How would that affect fuel economy?<br /><br />Here is a photo of the drive with the existing prop:<br /><br />

 

[simidrm-45844]

Re: Propeller Questions

First off I have the same problem and the cheapest why to fix the problem,was to buy a prop from www.piranha.com it is an all composite plastic prop with removeable blades they are 165.00 for that out drive I just bought one for my volvo 275 the hub is guarenteed for life and they blades are replaceable for 20.00 a blade and best of all if you need to repitch your prop and you haven't damaged your blades they will trade you free of charge to a different pitch.<br />but i suggest you change your outdrive to RH rotation it only takes a few minutes and you don't need any parts.<br />Volvo outdrives can be run in either RH or LH roation but today most outdrive are RH and to get a LH prop they have to be ordered so......<br /><br />Take the 2 screws out of the cover on the back of your outdrive (2 phillips screws) only the bottom screw comes out the top is just a paw that holds the top in but you need to loosen it also,<br />look on the inside of the cover and it shows you a picture of the linkage in either Rh or Lh rotation, RH roation the linkage is on the right side of the shift mechanism take the 2 cotter pins out and move the linkage to the other side with the linkage pins to the inside and you have sucessfully changed rotaion and props are usually kept in stock for rh