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Post by gnrphil on Apr 5, 2015 18:54:11 GMT -6
I raised the motor one hole last weekend and took her out to the beach today, with a full tank of fuel and six people (4 adults 2 kids) on board I gained about 3 mph ( previously running 40 at WOT). 43 mph at 5500 rpm, happy with that as I'm under propped.
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Post by Juan on Apr 6, 2015 5:57:30 GMT -6
Glad it worked out for ya.. those are decent numbers. I'd be happy with that too. I need to lower the motor on the bass boat a notch this week cuz it's blowing out with just a little trim... I'm just not looking forward to doing it because the mounting bolts are going to be a bugger to get off! 021
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Post by gnrphil on Apr 6, 2015 11:09:03 GMT -6
Mine came out easy, only problem was digging out 5200 somebody filled the bottom bolt slots with
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Post by gnrphil on Apr 20, 2015 6:23:23 GMT -6
I had exactly the same results other than the speed increase although I feel I could go up to last hole also, I need to get it propped right first. I bought a used manual jack plate but I don't think I'm going to use it, let me know if you'd be interested in it.
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Post by gnrphil on Apr 20, 2015 11:39:16 GMT -6
Will do. emthup
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985crabs
Captain
2000 V1900 Bay Series, Yamaha 150 Carb. 2
Posts: 1,309
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Post by 985crabs on Apr 20, 2015 11:55:35 GMT -6
I'm just not looking forward to doing it because the mounting bolts are going to be a bugger to get off! 021 Juan, I'm sure that a man of your vast experience knows this, but I'm told that the way one makes that job simpler is to heat those bolts with heat gun prior to trying to turn the nuts. It gets all the molecules excited and makes them much easier to move.
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Post by Juan on Apr 20, 2015 13:10:41 GMT -6
I'm just not looking forward to doing it because the mounting bolts are going to be a bugger to get off! 021 Juan, I'm sure that a man of your vast experience knows this, but I'm told that the way one makes that job simpler is to heat those bolts with heat gun prior to trying to turn the nuts. It gets all the molecules excited and makes them much easier to move. I don't much like using my torch around fiberglass. I know heat works to loosen bolts but I never have fully understood how. Since heat expands metal and cold contracts, you would think that heating metals would make the bolts harder to remove and cold would make it easier. I plan to spray the heck out of them with WD-40.
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Post by Simple Man on Apr 21, 2015 5:50:30 GMT -6
Heat expands the bolt (makes it longer) thus loosens it some making it easier to remove. Big time problem in refineries during start up (leaks during startup due to loosened bolts). You have to go back in and "hot torque" a lot of equipment once above a certain temp. Funny thing is now I work in a cryogenic facility you have the same problem there some what due to shrinkage rate of different materials and components loosening connections! So Juan your right in your confusion, It does work both ways!
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Post by gnrphil on Jun 2, 2015 13:49:13 GMT -6
Thought I'd update this one with fuel burn results now that I've figured the correct way to fill the darn thing up 021 Cruising about 5200 rpm (still under propped) @ 36-7 mph I achieved 2.9 mpg , pretty happy with that from a 2002 2 stroke.
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Post by seagristle on Jun 3, 2015 10:00:21 GMT -6
grnphil, what size prop are you currently turning?
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Post by gnrphil on Jun 3, 2015 11:42:42 GMT -6
grnphil, what size prop are you currently turning? I'm running a 14x15 stainless right now, the Yamaha PB lists a 13 3/4 x 17 which I purchased of flea bay but the hub is too long . I did try a merc 14x19 for gigles and it did quite well but no real speed increase and an obvious drop in RPM, it did give nice cruise numbers though and a little more stern lift. I've found with the 15 pitch once I reach top speed I can increase the throttle with no gain. SC I totally agree with you @ 5500 rpm and 42 MPH I'm getting 0.0 slip according to the Hearing prop slip calculator 15 pitch prop 1.86 gear ratio These numbers are with a full tank of gas (105 gallons) and two people on board .
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Post by gnrphil on Jun 4, 2015 16:13:36 GMT -6
Those are almost unbelievable numbers that might be defying physics. 0% slip. Are you sure about the RPM and mph or the pitch of your prop. Racing guys that are trying to get everything out of their setups get to only 5% slip. At WOT you are doing well at 10% or less, or so told. So anything in a general purpose prop between 5 and 10 percent slip is fabulous. If you are truly indeed getting those numbers and inputs are correct, don't touch a thing. Keep that boat full of whatever your burning and don't let anyone off the boat. I know it doesn't seem right to me either, I'll check again this weekend. I'd say I'm sure of the pitch but who know's it may have been adjusted, I don't know what make it is.
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Post by gnrphil on Jun 7, 2015 17:32:58 GMT -6
40 mph @5400 rpm that's 3% slip, good numbers I think
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Post by gtightline on Jun 8, 2015 9:41:46 GMT -6
3% slip is amazing...Good job !
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Post by gnrphil on Jun 8, 2015 11:53:11 GMT -6
Thanks mate, surprised about it to be honest as I've always said I need a 17 pitch prop. I guess I don't and I was running 41 - 42 with the tide which yeilds even better numbers boating2
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Post by gtightline on Jun 20, 2015 6:27:54 GMT -6
Here's my boat trimmed out and running well..about 45-48 mph @ 55-5800 rpm...
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Post by Juan on Jun 20, 2015 6:34:41 GMT -6
Here's my boat trimmed out and running well..about 45-48 mph @ 55-5800 rpm... Isn't it hard to handle going that fast on it's side?
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Post by gtightline on Jun 20, 2015 6:46:48 GMT -6
Hahaha..I hear you Juan....I don't know why some of these pictures come out sideways, haven't figured that one out yet. We had a good time yesterday and caught a bunch of fish which we threw back, I won't eat anything out of the South East Everglades.....Bass, lots of of Pan Fish, and Chain Pickerel..here's a picture of one of the Pickerels...I hope these pictures are upright...Hahaha
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Post by gtightline on Jun 20, 2015 6:48:02 GMT -6
Still sideways....Oh well, back to the drawing board, as they say.
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Post by Juan on Jun 20, 2015 6:59:23 GMT -6
Sweet! I think Chain Pickerel are called Jacks up here.. Try saving your pictures to an internet picture saving site like Photobucket or Shutterfly before posting them on the forum.. they'll show up right side up and bigger. emthup
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