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Random Quote: Naw, its okay,,, its always made that sound.
My dealer "gave" me (all right, he sold me ) a 14 1/4 X 17 prop (for a Sea Hunt Triton 220cc with an F150 Yamaha). I can only pull about 5100 RPM with that rig no matter how I trim it. It seems to me that I have the wrong prop.
My initial thought was that I needed a lower pitch, but I went on the Yamah web site and note that they were using a 14 1/4 X 18 on their test of the Sea Hunt Victory 220 (which is the same hull in Walk Around format) and they were able to pull 5900 RPM with the same engine. My inclination is to try the same prop that they were using. Am I going in the wrong direction here? (I do have very good low and mid-range performance with this prop).
I am inititially wondering if you actually got a 17 inch prop? Are there any markings on there that specifically say "17" or 14 1/4 x 17? I have seen and heard of far too many people that get a certain sized prop from the dealer, only to find out it is another size.
Was this a used or new one? If it was used, it could have been re-pitched?
I would take it back and ask for another. If you get the same results, then drop down a size.
Good luck!
__________________ - Chris
Guess What?? I got a Fever.. And the only prescription is.. MORE COWBELL!
-2011 Blue Wave 2400 Pure Bay / Yamaha F300 4.2 with Command Link Plus
-2003 Sea Fox 195 Bayfisher - Mercury 125 Saltwater Classic (Sold)
-1994 Wellcraft V-20 Step Lift (Sold)
No one can really tell you what size of prop to use on your particularly boat, loaded the way you load it and operated the way you operate it. That is why it is meaningless to try and compare your boat with someone elses. Maybe as a starting point but that is all. Yamaha might have run their test in the winter time with one person on board and minimum fuel. It is now the hottest part of the summer and engine performance will be way down, naturally. Maybe you have a full load of gas, anchor, anchor rope, tackle, ice, friends, dogs, on board, etc, etc.
What is known, and stated in your owners manual, is that you should select a prop that will let YOUR BOAT operate in the UPPER end of the specified RPM range with a FULL load, on a hot and humid day. This will give you maximum performance while achieving the most life the engine has to offer.
You have a tachometer obviously. Once you have propped the boat correctly you will need to make sure that you do not exceed the rated RPM if you ever operate lightly loaded on a cold and dry day.
I would try a few things to make sure everything else is optimized before messing with props. Do NOT change more than one thing at a time. Where is the cav plate vs the hull bottom? Reducing the "x" dimension (by raisng the motor) until you start to get a little cavitation in high speed turns is a good place to start, after making sure the motor is running right (timing, plugs firing well, etc.). Also, have you tried trimming for a little bow light to where you start to get some bow slap in calm water? That trim will usually yield best speed and engine RPM. Based on what you found on the Yam website, your motor should be turning more like 6100 or more, since an inch of pitch is worth ~ 150 to 200 RPM and your hull is lighter than a W/A. I would try to get the dealer to work with you. What you have is not right.
__________________ ================================================== ==
A bad day fishing is always better than a good day at work.
You cant really trust what the dealer gives you. The idiots I bought my rig from put on an SS prop that was for a small gear case Merc and I have the LARGE gear case!!!!!! Now you can imagine what the gap around the outside of the prop did for performance?? The exhaust gasses on the outside of the prop were allowing the prop to ventilate wildly. That POS will turn 10K rpms if you let it go and it tops out at about 30 mph. I knew I was going to change it anyway so it didnt matter. Another dealer screw up
Drop to a 15" pitch and your RPM's will increase....
I would not go lower than 15" pitch ...
John
That's what I would have thought, but no one else seems to need to go that low on this boat. Something isn't adding up here. I have 2 tests by Yamaha on this boat 1 with the 14 1/4 X 18 and one with a 13 3/4 X 19. Mine is an aftermarket SS prop and it is marked as a 14 1/4 X 17. I would expect it to pull more RPM than the 14 1/4 X 18, but mine doesn't... I'm wondering if there is something wrong with my motor or my prop. The motor certainly seems fine. The prop is always a bit of a wild card... I'm strongly tempted to buy the Yamaha prop used in the test -- even though it doesn't appear as if that is the right direction to go.
I am inititially wondering if you actually got a 17 inch prop? Are there any markings on there that specifically say "17" or 14 1/4 x 17? I have seen and heard of far too many people that get a certain sized prop from the dealer, only to find out it is another size.
Was this a used or new one? If it was used, it could have been re-pitched?
I would take it back and ask for another. If you get the same results, then drop down a size.
Good luck!
It is marked as a 14 1/4 X 17 -- but props have been mismarked in the past! I think I may go with the Yamaha performance prop used in the test and see what I get. My boat is loaded very similarly to the test boat so I shouldn't have the differences that I am seeing.
Something isn't right, you should definitely be running the Yamaha Performance* Series 14.25" X 18 stainless steel prop on that engine and boat.
Check the prop again and make sure of what you have, you want part number MAR-GYT3B-V6-18.
Well, you certainly seem to be having the same reaction that I am. I don't think I should need to go lower than a 17 and since my boat is loaded about the same as the tested boat (it is a WA, but I have a t-top and 2 batteries on my CC), I would think I would get similar performance with that prop. I think I am going to order one from the THT Yamaha vendor and see how it does.
Well it can't be the perfomance series prop since it only comes in at 14.25/16 or 18 on up. If you are using a SWS ( saltwater series prop) it's too aggressive for your setup.
The prop used in the performance bulletin is:
14 1/4 18 Series M For VZ150 and 150hp 36 ~ 46 mph MAR-GYT3B-V6-18 performance series three blade
I may have missed this in someone elses post but the engine may be set to low. Can the engine be raised to the next hole? If the prop does not blow out, this should give you a few additional rpms. Is the prop that you have heavily cupped or is it bone stock?
__________________
"Of all tyrannies a tyranny sincerely exercised for the good
of its victim may be the most oppressive." ~ C.S.Lewis
Well it can't be the perfomance series prop since it only comes in at 14.25/16 or 18 on up. If you are using a SWS ( saltwater series prop) it's too aggressive for your setup.
The prop used in the performance bulletin is:
14 1/4 18 Series M For VZ150 and 150hp 36 ~ 46 mph MAR-GYT3B-V6-18 performance series three blade
Well, the prop that I have is a Solas New Saturn SS prop (#3531-143-17) which should be a good prop for this boat. Indeed, according to Solas it is pretty close to the Yamaha 6G5 45978- 03 - 98 (13 3/4 X 17) which was tested by Yamaha on my boat/motor combination and did 5800 RPM so my problem may well be somewhere else. I'm going to check everything over this weekend again and see if I can find anything wrong before buying new... FWIW, everything looks right and feels right - it just doesn't rev up the way it should.
I may have missed this in someone elses post but the engine may be set to low. Can the engine be raised to the next hole? If the prop does not blow out, this should give you a few additional rpms. Is the prop that you have heavily cupped or is it bone stock?
It is a Solas New Saturn. I'm going to run down and check where it is set. I don't think it is low, but it's worth a try.
I have twin F150's running Black Steel Yamaha 14 1/2 x 19's. These are fast props but fully fueled I can only turn 5200 so I just ordered a set of S.S. Turbo 14 1/4 x 17's. All props mentioned are 3 blade. Based on others performance with a similar change and the same boat I anticipate being able to hit 56-5800 fully fueled and hopefully with trim I can hit the maximum range of 59-6000 rpm. I have read most of the Performance Reports on the F150 from the Yamaha site and there are very few (that I recall) where anything other than 17-18 in. pitch is used and the engines hit the upper range at W.O.T.
__________________
USCG Licensed 100 Ton Master 1987-2007
I would try a few things to make sure everything else is optimized before messing with props. Do NOT change more than one thing at a time. Where is the cav plate vs the hull bottom? Reducing the "x" dimension (by raisng the motor) until you start to get a little cavitation in high speed turns is a good place to start, after making sure the motor is running right (timing, plugs firing well, etc.). Also, have you tried trimming for a little bow light to where you start to get some bow slap in calm water? That trim will usually yield best speed and engine RPM. Based on what you found on the Yam website, your motor should be turning more like 6100 or more, since an inch of pitch is worth ~ 150 to 200 RPM and your hull is lighter than a W/A. I would try to get the dealer to work with you. What you have is not right.
WildeOne:
Well, your advice turned out best. I just couldn't believe that my boat would be that different from other people's boats so I decided to go over each parameter one at a time. Each one checked out OK (while I was tempted to move the motor up one hole, it already was one hole higher than the test boats). In that process, a number of Sea Hunt owners on the Sea Hunt forum indicated that their boats went much better with trim tabs. While I had trimmed the bow way up before (to the point that it became uncomfortable) I kept going this morning till the motor would go no further. To my great surprise, over the last few degrees of trim range, speed picked up a whole lot. Got all the way up to 5800 and over 42 MPH. That's more what I expected to see and I have come to the conclusion that trim is the problem. I think I am going to have to get tabs. That will be a great Winter project.
Proper propeller size 
) a 14 1/4 X 17 prop (for a Sea Hunt Triton 220cc with an F150 Yamaha). I can only pull about 5100 RPM with that rig no matter how I trim it. It seems to me that I have the wrong prop.
