I just bought my first boat. I'm wondering a bit about speeds. I have a Yamaha f200 on it and at around 5500 rpm I only go about 28 mph. Is this normal?
1995 Adventure 208 Speed
- Thread starter Toatts
- Start date
I top out at 40 mph and I only have a 150 hp (2 stroke v6). Advice above is best approach.
Also, how is your hole shot? If good likely not prop slip although that seems most likely l.
What is top rpm's for your engine?
Also what prop are you running, could be wrong pitch.
Also, how is your hole shot? If good likely not prop slip although that seems most likely l.
What is top rpm's for your engine?
Also what prop are you running, could be wrong pitch.
Check out the 208 Performance Specs page on the website with the F200. I have a new F150 and am pretty close.
https://www.gradywhite.com/models/walkaround-cabins/adventure-208/
https://www.gradywhite.com/models/walkaround-cabins/adventure-208/
I think it's the prop. I'm going to take it into an outboard shop this week. Do you have any idea what that might cost to get fixed? I saw some people talking around 100-200$. Is that all it would be?
Last prop I had rehubbed, tuned and balanced cost about $225 in the NYC area.
I would advise you to see if you can borrow a prop from someone to see if it makes a big difference. Although your prop may be bad, I am not totally convinced that a bad prop is your issue.
On my 2001 208 with sx150, I get about 32mph at 5200 revs. I usually don't run at that speed, more like 21mph at 3600 or thereabouts.
For the record, how are you measuring your speed?
is your reported speed verified by gps. pay zero attention to a speedometer on a boat. get gps speed before you do anything. there arefree phone apps that can do this if need be.
how much bottom paint? a lot of bottom paint or an uneven keel line caused by uneven paint can create a lot of drag.
with the engine hanging fully down to the transom, lay a yardstick along the bottom of your keel extended out to the motor and see if the lowest prop foil/vane on the motor leg is below or above the keel line prescribed by the yard stick. it should be the same height or slightly higher. if it is lower, that buries the vane and creates drag, which could explain your performance.
also, look on the blades of your prop for stamped numbers. something like 15x17 and also a serial number. report what you see.
how much bottom paint? a lot of bottom paint or an uneven keel line caused by uneven paint can create a lot of drag.
with the engine hanging fully down to the transom, lay a yardstick along the bottom of your keel extended out to the motor and see if the lowest prop foil/vane on the motor leg is below or above the keel line prescribed by the yard stick. it should be the same height or slightly higher. if it is lower, that buries the vane and creates drag, which could explain your performance.
also, look on the blades of your prop for stamped numbers. something like 15x17 and also a serial number. report what you see.
I was using the GPS from navionics and compared it to my speedometer. I think the speedometer ready about 25 mph and GPS 28
Wife just went into labor. Will report back in a week or so. Thanks!
bring the boat to the hospital parking lot and you can do all that stuff while you are waiting.
also, good luck and congrats!
Baby and mama are doing great. Just a little fussy. Thanks for the support!
@suzukidave The dang parking garage was too full. I wouldn't have been able to find a parking spot.
@seasick I got the dimensions for my prop
E3x14.8x19R
Solas
MYH
That's everything stamped on the prop. Below are pictures of each fin of the prop.
Also below are pictures of how the keel lines up with the engine. When engine is fully trimmed down the first horizontal fin lines up with the bottom of the keel.
Attachments
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1.jpg -
2.jpg -
3.jpg -
4.jpg -
5.jpg
everything on the prop that is visible is
E3x14.8x19R
Solas
MYH
I talked to the previous owner and he said that he has never changed the prop. It's the stock one that came in 2005.
I went down a rabbit hole on other forums... does anyone think it could be water logged foam and my boat is just too heavy?
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5500rpm at 28mph on a 19" prop makes no sense. that is 43% slip. you should be running over 45mph with 10% or less slip. is the hull bottom clean and smooth?
can you borrow or test another prop? partially spun prop is my first guess
can you borrow or test another prop? partially spun prop is my first guess
so a spun prop is what another guy suggested. the hull bottom is painted pretty terribly. I did see other posts and one guy he said he has my setup and his boat runs 40+ with it "painted with a mop". ill be taking it to a prop guy sometime next week.
So bad news, the prop doesn't seem to make a difference. I got a new prop all together. I'm running a 3 blade 14.75x17. Still looking at about 30 Knots at 5500 RPM. From what I understand the bottom paint can slow me down because its really rough and not a great paint job. I'm having some work done to fix that over the winter. What else could be slowing me down? Could the engine not be producing as much horsepower as it needs?
@CJ7Rob
@trapper
@suzukidave
@ric2352
@CJ7Rob
@trapper
@suzukidave
@ric2352
So I watched this video on mounting engines. I THINK my engine is mounted too low.
@ 3:50 he talks about the water pickups need to be in line with the bottom of the hull. My anti cavitation plate is level with the bottom of the boat. And then goes on to talk about if it is too low and water goes over the anti cavitation plate then you'll have a bow high ride. Well I have a bow high ride.
I'm hoping this is my problem because I'm getting the transom rebuilt which will result in the engine being remounted.
I'm hoping this is my problem because I'm getting the transom rebuilt which will result in the engine being remounted.