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| Just curious as to what the top end and RPM's should be on a Tuffy 1760 DW with a 150 Opti on the back? After the break in period, I have so far been able to get to 47 MPH at around 5200 RPM's WOT. This is with a 19pitch Tempest prop. I have been playing the trim to maximize the speed without blowing it out. I was told this rig should be able to hit around 55 MPH. I am not bummed out if it only goes 47, but am curious if I somehow am not getting the performance out of it I should be... Thanks for any responses. |
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| With all my gear and a a full to half tank of gas i can get about 48-49 with mine with a yammy f150 and a 6" jackplate. I'm sorry but that is about as good as your going to get out of her. |
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Member
Posts: 3899
| 5200 RPM is a bit low. This should be a 50+ MPH boat. What hole is the motor in? Is the prop in good shape? Is all your weight in the back?
I've been in 1760's with the 150 Opti at 52-54, conditions depending. It should perform better than a 150 4-stroke. Better hole shot, midrange, top end.
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Member
Posts: 25
| I am not sure but I think I know what you mean when you ask what hole is the motor in. Apparently, it looks as if there is no bar across any of the "holes" in the area where the motor trims. OR are you talking about the way the motor is mounted on the transom. I am the one who is confused I guess. On my old 40 hp merc, there was a bar that would lay horizontally across the back end and that would then seem to affect how the trim positions worked. Is this the area you are talking about??? I have most of the weight in storage which is up front. Also, my speedo doesn't work as I don't think it is hooked up, so I have to rely on GPS accuracy which should be pretty good I think. Prop doesn't have a nick on it, and the engine maybe has 6-7 hours on it total. Everything is 2006 just got the boat this spring. Holeshot is awesome. 2-3 seconds and you are up there and going. I am still wondering why I am not getting more rpm's. Could my throttle not be pulling all the cable it can? |
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Member
Posts: 1382
| Give it a few more hours to get that Opti totally broken in. Look at the bolts at the top of the bracket, is there an open hole above the bolts? |
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| The bolts are mounted at the top. There are no openings above the bolts. Should this motor be mounted differently to get more performance? |
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Member
Posts: 3899
| Merk Kid and Slamr have the new 1760, with 150 Opti's. Perhaps they will chime in with what hole their motors are in, and what they are getting for speeds. |
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Member
Posts: 1040
Location: Stevens Point, WI | Cast-n-blast,
I am getting about the same speeds that you are talking about right now. I think I hit 48 1/2 on GPS one day but that 47mph range is usually where I'm at right now. Talked to Slamr the other day when he was up and he said the same thing. I think he hit 49mph but for the most part, I think he was right around 47 to 48mph. I will check the hole placement on my Opti tonight and will let you know. |
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| In other words your motor is sitting down tight to the transom. Deffinately wrong. That boat should have the motor mounted on 3rd hole from the top and depending on your rig and set up, maybe even the 4th.
I set up a several year old 1760 SC with a 150 Yammi EFI and it does 59 GPS. A 115 4 stroke is dead on at 41. The 150 is on the 4th hole from the top and the 115 is on the 3rd. The 150 of course has an ss prop.
When you find the proper motor hight, you will most likely cavitate in a corner. Drop the trim as you come into the corner and raise it again when you come out of it.
I'll play with motor hight untill it blows out going straight. Then drop it back down
usually one hole.
E-mail me if you have any more questions. [email protected].
I don't even rig a 16ft tin boat with the motor all the way down on the transom. Standard rigging in my shop for the average boat is the 2nd hole. If there are any running problems, most of the time it needs to have the motor raised higher. |
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Member
Posts: 25
| Terry, that is correct, it is sitting down but not directly on the transom. What do you suppose it would cost me to remount this beast? Is it necessary? would I achieve more speed? OR, do I just leave well enough alone? Opinions? |
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| I can assure you there is no way you will ever get the new 1760's to 59, and i highly doubt you could get the old ones to 59. The 1760 isn't the fastest 17ft boat out there, but it is by far the best riding. |
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| It shouldn't take more than an hour to lift the motor a couple of mounting hole.
Be sure to re-silicone the bolt holes.
Yes you should be able to get more top end out of it. Hole shot should improve as will handling. With the motor that low, it is "dragging" in the water. You probally have a lot of sprat coming off of the cavitation plate, even up on plane and trimmed. The less spray without cavitating the better. A noticable difference should be felt in overall handling under power.
I would never exagerate, such as in the speed, just to make a boat look better. My experiences in this boat are actual. |
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| SLIPKNOT - 6/26/2007 3:34 AM
I can assure you there is no way you will ever get the new 1760's to 59, and i highly doubt you could get the old ones to 59. The 1760 isn't the fastest 17ft boat out there, but it is by far the best riding.
Certainly won't get there with a yammy. lightly loaded, one guy, and a few gallons of fuel, and a 2 stroke DFI will get it there. |
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Location: Rhinelander | Mr. Marine out of Fond Du Lac has rigged several 1760s that run 60ish, as has Terry at Wild River. It's ALL propping and engine height, load and conditions. A 6" set back really helps the top end on that boat. |
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