Can someone tell me what prop they are running on a 241 offshore with 350 Magnum I/O? Recently purchased this boat and want to get a SS prop for it.
241 Offshore prop
- Thread starter VeroWing
- Start date
Load in the boat, age of the motor, etc can all change what prop is ideal for a particular boat. While manufacturers tend to prop their boats with a only a partial load, I prefer to prop it based on your normal load. With that in mind, what is your current WOT (trimmed up, going as fast as you can)? Also, what is the purpose that you have in mind for an SS prop? Everything else aside, you can just get the same pitch SS as your aluminum is.
Thanks for your reply Dennis. I'm in a unique situation with this boat. I bought it locally from a person that had boat sitting for a few years and ss prop on boat was taken by someone. Owner had a spare aluminum prop that looked like it had been used in a cement mixer he threw on to sell boat. This prop has no numbers on it, so I'm looking for a ball park size in SS that similar 241s are using. I've repropped several other boats before and understand the goals to look for when propping a boat. I run primarily offshore and prefer the SS which is thinner, stronger, doesn't flex or wear, can be cupped, and once you zero one in, is more efficient.
By the way, I have not run this boat yet, and won't do so with the prop on there, it is in really bad shape. The boat needs a complete going over too.
By the way, I have not run this boat yet, and won't do so with the prop on there, it is in really bad shape. The boat needs a complete going over too.
Gotcha. I understand.
Cement mixer? That's a good one - made me laugh!
In lieu of hearing from someone else, couple other ideas...
Some manufacturers, Sea Ray for one, publishes prop charts for their boats - even going back many, many years. I have not checked on Grady's site, but maybe they do, as well? Or, a call to a local dealer or right to Grady might be worthwhile, too.
Also - do you have a good Mercruiser shop near you... or even just a prop shop? They may have a try-it-before-you-buy-it program.
If I had to guess, I would think something like a Vengeance or Mirage, 19" would at least be close.
Another thought... on Merc's website, there is a prop section. You enter some criteria and it recommends some props for you.
I know I'm not giving you a direct answer, but maybe this will at least help.
Cement mixer? That's a good one - made me laugh!
In lieu of hearing from someone else, couple other ideas...
Some manufacturers, Sea Ray for one, publishes prop charts for their boats - even going back many, many years. I have not checked on Grady's site, but maybe they do, as well? Or, a call to a local dealer or right to Grady might be worthwhile, too.
Also - do you have a good Mercruiser shop near you... or even just a prop shop? They may have a try-it-before-you-buy-it program.
If I had to guess, I would think something like a Vengeance or Mirage, 19" would at least be close.
Another thought... on Merc's website, there is a prop section. You enter some criteria and it recommends some props for you.
I know I'm not giving you a direct answer, but maybe this will at least help.
I sent a request in to Grady to ask what they originally install on this boat, and awaiting their reply. I was hoping someone on here with a 241 Offshore model could tell me what they are running.
I am turning a 17" aluminum...don't think a 19" would work.
Also need to know your OD ratio, should be 1.5:1.
Also need to know your OD ratio, should be 1.5:1.
'84Offshore said:
Thanks for reply. The 17 you're running , do you know what pitch it is, and is it aluminum or SS? Does it run up to correct rpms at wot? Hope you don't mind all these questions, I'm trying to get this boat set up right for some good offshore fishing and appreciate any info you can give me.
This is the prop......the pitch is 17". http://boatpropellers.iboats.com/Me...148-17_Propeller/773/20407/?cart_id=400066424
i get 30MPH at ~3600RPM and ~40MPH at WOT (~4500 RPM)......
i get 30MPH at ~3600RPM and ~40MPH at WOT (~4500 RPM)......
I like this prop.........seems to "grip" well.
Also, I have vortec heads on my engine that supposedly adds ~30hp.........not sure if you have a Vortec engine.
The intake manifold will have 8 bolts instead of 12 if it's a vortec.
Also, I have vortec heads on my engine that supposedly adds ~30hp.........not sure if you have a Vortec engine.
The intake manifold will have 8 bolts instead of 12 if it's a vortec.
'84Offshore said:
I'll have to check intake manifold bolts. I'm trying to get a date on the Mercruiser package in this boat. Previous owner told me he bought boat from a friend several years ago and just before buying the friend had a new 350 Magnum alphs1 gen 2 package installed. He told me it has 250 total hours on it and has been sitting since he bought it. So far I've been unable to find any numbers to identify what or when it was produced. I'm just getting started on going through boat, and it will need a complete checking.
If you can tell me the engine serial number and drive serial number, I can see if I can tell you some info about both of those, including when they were first put into service - possibly any warranty service that was done, as well.
DennisG01 said:
Found a tag above starter and number looks like K278713 which from what I gather is a 1997. On top rear of upper outdrive is this number. OK238795 if I'm seeing it right. There was another number but this one says serial number.
Here is a pic of engine.
Interesting. The tag near the starter (flywheel housing) is the "hidden" serial number that many people don't know about. Using that number, that engine was made in May '97, but was not registered (sold) until July of 2000 in PA... here's the kicker... it was in a Baja Sidewinder! I think I may have actually sold that boat - the guys name sounds familiar!!!! I work part time (sales and service) at a Sea Ray dealership and we used to also sell Baja.
This is the info that goes along with that first number:
ENG: 0K278713 4350100KS MERCRUISER 350 ALPHA
DRV: 0L101059 5121200LS MERCRUISER ALPHA 1.47:1
TRN: 0L202064 6111001LS MERCRUISER ALPHA TRANSOM
Using the transom number (the second number you listed) I get this info. Produced in April of '97 and sold in July '97. It doesn't tell me the actual boat, just that it was in South Carolina and was in a "Fiberglass, pleasure, salt". Certainly sounds more like a Grady. Note the closeness of the two serial numbers - the last numbers are either a "3" or a "1" - could the tag on your flywheel housing actually have a "1" at the end, instead of a "3"?
ENG: 0K278711 4350100KS 1997 MERCRUISER 350 ALPHA
DRV: 0K241268 5010147KS 1997 MERCRUISER ALPHA 1.47:1
TRN: 0K238795 6010000KS 1997 MERCRUISER ALPHA TRANSOM
This is the info that goes along with that first number:
ENG: 0K278713 4350100KS MERCRUISER 350 ALPHA
DRV: 0L101059 5121200LS MERCRUISER ALPHA 1.47:1
TRN: 0L202064 6111001LS MERCRUISER ALPHA TRANSOM
Using the transom number (the second number you listed) I get this info. Produced in April of '97 and sold in July '97. It doesn't tell me the actual boat, just that it was in South Carolina and was in a "Fiberglass, pleasure, salt". Certainly sounds more like a Grady. Note the closeness of the two serial numbers - the last numbers are either a "3" or a "1" - could the tag on your flywheel housing actually have a "1" at the end, instead of a "3"?
ENG: 0K278711 4350100KS 1997 MERCRUISER 350 ALPHA
DRV: 0K241268 5010147KS 1997 MERCRUISER ALPHA 1.47:1
TRN: 0K238795 6010000KS 1997 MERCRUISER ALPHA TRANSOM
DennisG01 said:
Dennis, thanks for getting this info for me. A few digits in serial numbers could possibly be incorrect, both were hard to read. The one on flywheel housing I read backwards and upside down through a mirror, and the one on upper outdrive was barely readable, but I'll check them again today. Doesn't correspond very well with info previous owner told me, but I guess it's always "buyer beware". He indicated to me that this engine/outdrive package was purchased/installed new in boat a short time before he bought it "several" years ago from a close friend, and have 250 hours on them. He said his construction business went bad shortly after buying boat and it has been sitting for a few years without usage. I think a "few" years may be more than what I was thinking. I'm just beginning to thoroughly go through boat, and have not even tried to fire engine yet. I'm hoping not to find too many disappointing items, but I know how it is with these things. The hull looks nice and solid, and actually engine/outdrive is not showing a lot of use, so hopefully they'll end up being in good shape.
I know what you mean about using a mirror... upside down, backwards, reversed, awkward angle, hard to focus a flashlight on it, left is right/right is left... am I missing anything? I use my phone - either pictures or video. Sometimes the built in flash/light is enough. That seems to work much better for me.
Good luck!
Good luck!
Here's a shot of flywheel housing with a camera. It's the best of 7 or 8 of them.
I cleaned number on upper outdrive housing with windex and it is now pretty much invisible.
I cleaned number on upper outdrive housing with windex and it is now pretty much invisible.
Well, the last digit definitely doesn't look like a "1". I tried with an "8" and a "0" - one matched to a Sea Ray and one to a Bayliner. It certainly looks like it could be a "3", but a "1" is the only thing that makes sense based the results - but it sure as heck doesn't look like a "1". I wonder if the engine was removed from the Baja somewhere along the line? I dunno!
DennisG01 said:
I'm going to try rubbing a pencil across number then putting scotch tape on it to see if I can get a better look at it, but it looks like heavy rain here for a few days. At least I now know the year and specs I need to go by to get it tuned correctly. I must admit though, I have an urge to go to the previous owners house and hit him over the head with a shovel, :<>< :-| but I'll wait and see how it runs first.