i think this is a good base to start from
full tank of Fuel 25+ gal
2 people 350lbs
full rpm @6200
speed trimmed just right 49.7 mph (gps)
having that mcuh fuel is a lot of weight so i should expect more speed after getting lighter
so tommorrow i taking the boat in and dropping the motor all the way down and i should drop rpm and gaim more speed
Jimmie,
I would think you should be getting in the 60's somewhere with that rig but not sure. You might need more prop if you're pulling 6200 with that heavy of load. What prop are you running?
not sure of the brand all it said is
it a 4 grade 26p. is engraved on the prop
think that why the dealer guy wants to drop it lower on the transom
Well, maybe 60's is stretching it for that rig, but I had an 18 1/2 foot Champion with a 175 yammie on it and I got into the low to mid 60's. I can't believe your boat would be heavier. If you've got good water pressure and good lift, I wouldn't go down on the transom, I would leave it where it was at and work on getting her propped right. Normally a 175 on an 18 footer should have your screamin' What is your propshaft distance under pad?
that why i asked the other day
the boat and the motor need to be level
but i have found out thur Sherm that the motor a 89 not a 97 and the lower unit is a 2 to 1 gearing
so when i measure it to the center of the prop
also i dont have a water gauge
Dang jimmie.....................for an 18' boat & a 175 I would think you'de be faster than that.......Astro makes a hellava boat & agree that that should be a low 60's boat
From this pic & would say not.......& it looks to be dead on transome.....Maybe putting to 3rd/4th hole down may help & bigger pitch prop
NO Jack plate
this was all done on GPS yesterday on the back side protected by the wind
The two biggest things you could do to dramtically improve performance on your rig is to put on a jackplate and get her propped right. I could almost guarantee high 50's if your motor is tuned and running right, if not low 60's. Ryan runs as fast or faster than you right now with a 115.
well what funny the place i got it said they ran the boat and put 62 to 65
but a CALL B|S
due to i cant get it at 55 and the speed o is about 3 mph off
Jason................It sure feels faster than 50-52 MPH in a 17' boat though
well i know i had it on the speed o at 55 on a half tank but it off
Those numbers sound kind of screwy.
6200 rpm
49 MPH
26p prop.
I would think your speed at WOT would be considerably higher!!! Just doesnt seem right.. You must be getting alot of slippage....That boat will be slower than traditional pad style bass boats.. it is a fish-n-ski so dont expect to get the same numbers as similar length hp bass boats.. The hull design is different. That being said 49 MPH even loaded heavy seems SLOW...Not trying to be a smart arse, but you might want to let somebody with a little more experience take it for a run, and see what they think the problem is...
Jason is right.. i would not drop the motor. Not yet anyway
I am seeing mid to upper 60's in my boat...17'10" with a 10" jackplate running 5800 RPM's with a 25p tempest plus prop
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Those RPM's have to be off!!! I turn a 200HP Yamaha with a 25Mprop at 5850-5900 to 71(GPS) easily with a medium load.. (two fisherman and all our gear plus 25 gallons of gas) That is consistent speed.. Jimmie is pushing a bigger screw at almost 400 rmps faster than mine and only hitting 50ish MPH... Something is definately off... Say he loads the boat real light. those rpms are gonna go up a bit..Im thinking close to 6300-6350ish.. I dont know a whole lot about that motor, but that seems kinda high. That is a 175 pushing a 18 ft. boat.. Might want to get the tach checked out?
well the boat has what is called a Mariner <U>SKI</U> efi motor the lower unit i was told is a 2:1 gear ratio and at 6200rpm is maxed out
Gears would definately affect the performance.. I missed that in previous post... hmm still seems a little off though
Ya i talked to RANDY at the shop and he told me the mariner SKI is a 2:1 so if anything i need to run a 27P prop but first thing her want to do is Drop the motor to see if i can get the RMP to drop and to gain speed
he thinks it not BITING and got prop slip or somthing to that effect
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