Trying to determine the correct prop for my 2006 Sea hunt Triton 172 with an 06 Yamaha F90TLR 4-stoke.
It came with an aluminum prop of unknown pitch/diameter, so I checked with Skip’s and he recommended a Stiletto 13x17 prop, which I purchased and am currently using.
The problem with both props is the motor will rev to 7,000 RPM’s and beyond, while still only reaching into the high-30MPH range, occasionally 40-ish, with just me in the boat and maybe a half-tank of gas. I have only done this twice to determine top speed and WOT, etc.
I normally just cruise at around 5-5500 RPM’s, which gives me around 30-35MPH and excellent economy.
According to Sea Hunt’s website this boat should easily get into the low 40’s with 2 people and 2/3 tank of gas. Their data was collected using a Yamaha 13x18 prop.
I have tried to find one of these to try out and see if it is what I need but am having no luck.
I think a 19-pitch is too much and I’d have trouble planing.
I would like to find a used one locally that I can take out and try.
Anyone have a similar boat/motor combo or prop issue?
Any help appreciated!
2006 17’ Sea Hunt Triton w/ 90 Yamaha, formerly a 1991 15’ Key West Explorer w/ 60 Johnson.
When you get the 7000rpms, are you trimming the motor way up? According to Yamaha Motor Corp. WOT rpms are full throttle, with engine trimmed level. You can also take your prop to a shop and get more pitch put in it, might could try a 13 1/4 by 17.
When you get the 7000rpms, are you trimming the motor way up? According to Yamaha Motor Corp. WOT rpms are full throttle, with engine trimmed level. You can also take your prop to a shop and get more pitch put in it, might could try a 13 1/4 by 17.
No, normal trim, although I did try more up and down to see what effect it had.
I’m not sure what WOT is for my motor but I never go above 6,000, except when I tested it.
Also, wouldn’t a larger diameter just give it more bite and not affect top-speed?
2006 17’ Sea Hunt Triton w/ 90 Yamaha, formerly a 1991 15’ Key West Explorer w/ 60 Johnson.
You certainly need more pitch in the prop, and maybe some cupping. Stainless also performs much better than aluminum, it doesn’t flex as much. That engine should not be able to run over 6,000 rpms with the right prop. Not good for it! What size prop is on it now? It’s got a number stamped on the hub, or on the side between blades somewhere. Need to know that.
You certainly need more pitch in the prop, and maybe some cupping. Stainless also performs much better than aluminum, it doesn’t flex as much. That engine should not be able to run over 6,000 rpms with the right prop. Not good for it! What size prop is on it now? It’s got a number stamped on the hub, or on the side between blades somewhere. Need to know that.
Capt. Larry Teuton
Swamp Worshiper
Thanks CL. Current prop, as mentioned in the OP, is a stainless Stiletto 13x17 and it is cupped and ventilated.
Maybe I DO need a 19-pitch?
2006 17’ Sea Hunt Triton w/ 90 Yamaha, formerly a 1991 15’ Key West Explorer w/ 60 Johnson.
first off, something is wrong that needs to be addressed before you deal with the prop…
that motor is rev limited way before 7000 rpms.
either something is definitely wrong with your engine or the pole settings on your tach are not set properly. im betting the tach is off.
cant prop correctly with a bad tach
first off, something is wrong that needs to be addressed before you deal with the prop…
that motor is rev limited way before 7000 rpms.
either something is definitely wrong with your engine or the pole settings on your tach are not set properly. im betting the tach is off.
cant prop correctly with a bad tach
quote:that motor is rev limited way before 7000 rpms.
either something is definitely wrong with your engine or the pole settings on your tach are not set properly. im betting the tach is off.
Agree. Alarms would be going off on mine. Any chance the hub is slipping?
Who put in the tach? I bet it’s setup for the wrong # of cylinders.
If you need to try out different setups, skips will lend out new props after you purchase the first one and will take them back as long as the decal is still on and there are no chips or dings in it.
You may want to try different blade combo’s as well 4 vs 3. I also want to give Skip a thumbs up. He was the only person who had the prop I wanted I could not even order the one I wanted guess it isn’t made anymore. He had it on the shelf forever used out the door $150.00 He and his wife are truly another great thing we have access to in this area.
Who put in the tach? I bet it’s setup for the wrong # of cylinders.
If you need to try out different setups, skips will lend out new props after you purchase the first one and will take them back as long as the decal is still on and there are no chips or dings in it.
“Wailord”
1979 17’ Montauk
90 Johnson
Wilderness Ride 115
The tach is factory- installed. I’ll try and check it tonight or tomorrow.
I agree on Skip’s. They are great.
Thanks for all the info, tips and help everyone. I really appreciate it!
2006 17’ Sea Hunt Triton w/ 90 Yamaha, formerly a 1991 15’ Key West Explorer w/ 60 Johnson.
Like some have already said, I believe your tach is not responding correctly. You must fix that first.
You need to concentrate not only on RPMs but efficiency of the prop. You should be shooting for the least amount of slip as well as RPMs at WOT. I had a prop that kept my RPMs on target, but it ran with 18% slip. By increasing the diameter of the prop I was able to reduce my slip which gave me better fuel economy and a little more speed at WOT to boot. RPMs stayed on target.
If you want to try it, I have a 13 3/4" x17p Yamaha SS prop that I bought but couldn’t use.
You can do the numbers and get close, but IMO the only way to know how a prop will preform is put it on and run it. I’ve had two brand new props out of the “box” perform different. I’ve been lucky to know a few people willing to let me try different ones. Some boat shops used to let you borrow/rent used props.
Amazing what the “just right” prop will do for your boat. If only you could get one that got out of the hole quick under a heavy load and also got super top end. You are going to sacrifice on one end or the other.
Good luck on a good prop! and what everyone else said 7000 is way to high. I’d guess rev limiter is probably around 6200-6400? from what I’ve seen Chris could answer on that one.
“If Bruce Jenner can keep his wiener and be called a woman, I can keep my firearms and be considered disarmed.”
