It wasn't steady at 6200. It was 6150 flashing into 6200 now and again. So you are probably right that I was hitting the rev limiter. I don't know if my vessel view is any different from yours but just bought it new a couple months ago when I started testing as my analog gauge was off and my multimeter was not reading properly and jumping around a lot.
A single data point would be literally a single data point. I made dozens of runs all with the same results.Then you certainly know that you're not going to figure out what is going on from a single data point.
What does your data at 1000, 2000, 3000, 3500, 4000 and 4800 rpm look like?
How do those result overlay on your motors' power curve?
What you'll find is your out of Horsepower trying to swing the 15.....
As you can see below, the 15" prop consumed 35% more power while increasing speed just 13.3%.
Horsepower = Torque x rpm/5252
15" Prop
60 = T x 4,800/5252
T= 60 X 0.9139
T= 54.83
13" Prop
60 = T x 6,000/5252
T= 60 X 1.424
T= 85.4
I found the same thing exactly. Only thing that might explain this…other than what has been said by everyone…might be if you have a prop exhaust bore plastic sleeve ring there. Behind the prop. White thing. There was a re call on some models with this. Mine included. Allows venting of the prop when it comes loose.
Cool.
Nothing white there but these Hustler props have a black plastic ring that slips on to cover that gap, I assume thats what you are talking about? Both were new and seemed tight and fine...
Similar. But it’s actually in the exhaust cavity area. Called a bore sleeve or exhaust bore sleeve ring. Some mercs were re called and an improved ring was made. Unlikely the issue. But thought I’d mention. Usually larger gearcase. But your CT Bigfoot came to mind
Oh interesting I will have to look into that. The motor is a 2014. Any idea if that is in the effected range?
I’m honestly not sure if it affected your model or not. It may well have, being a larger gear case. It certainly affected my 2016 CT (what the Bigfoot is called these days). Looks like this and behind the prop in exhaust cavity. They are terrible for coming loose and allowing prop slip with exhaust venting through the blades. Have a look anyway. See below
I could not find any reference to that bore sleeve on any of the 40-60hp bigfoots. Here is a pic without the prop and one of the Hustler with the ring they put on the prop for that area. I have a 13.5"x 14" pitch Solas prop to try and it does not have that ring but the prop is tighter tolerance up there than the Hustler without the plastic ring but not as tight with the ring. I will take it for one more rip before committing to quit for the season. (Thats just grease in the first pic)
Both of the Solas are identical and no ring. They come with hub already in them. The turning point props had same hub and they did have a sealing ring. Turning point told me they have seen my results several times before. Look at the speed numbers. It's not blowing out lol.
Very similar results with two different manufacturers props. Turning point was worse than Solas though.
Nope, if you had read, the numbers came from the vesselview not a tach. Also the top speed I am getting is about all this boat does with a 60 bigfoot. Even matches up with all the prop calculators. The people with the same boat but the regular 60 instead of the Bigfoot get a few mph more but thats it. The slip calculators on pretty much all the props I have tried have shown them all very low slip.
Lol no offense but if you don't know what vesselview is and your telling me to get my rom from a mechanical tach that is literally calibrated from vesselview I have a hard time taking advice from you. The 13 pitch prop is too little prop, its not blowing out, its hitting the rev limiter which is why it only flashes 6200rpm occasionally. Again look at any boat with my similar specs and they do not go faster then low 30's withni
Dropped my phone mid sentence and it sent. You get the idea but look at the rpm difference from the 14 to 15 pitch... It's not 200 rpm.
Never heard of Vesselview before today. Think what you want, but a one inch pitch difference on pretty much any Outboard or I/O is going be a 200 rpm change. A 800 - 900 change is something else, Blow out from Exhaust, Ventilation from Surface Air, or severe Cavitation.
