Dialing - in new boat/motor

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fl.graderman

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Thank you, Pappy, for taking the time to read through my thread and offering up answers to several of my questions.
Especially the part about the rpm limiter. I pulled off my engine cover when I got home tonight and tried to find the numbers on the power pack. I couldn't see them, but it doesn't seem to matter because my engine doesn't rev anywhere near 61 OR 6200 rpm. I'm glad to hear the setup I have with the 12p prop will work. I plan to put it back on and call it finished.
In hindsight the "issues" I had with the motor were apparently just me over analyzing...

I have replaced the impeller and housing, fuel filter, spark plugs, and thermostat. I have been running 50:1 mix, but have no problem adding more oil. I'll try 24:1.

I bought this motor on ebay from a seller in kentucky for $1100. I didn't know ANYTHING about the Mirage motors or what I was buying...I'm glad I chose this motor! I am happy and now satisfied that this little powerhouse will do what I need it to...get me to the fish and back for years to come.

Thanks again!


2015 Tracker Grizzly 1448 MVX
1996 Evinrude 25hp 3 cylinder looper
 

Pappy

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I found that 24:1 was alot for this engine and for me to say that.....well.....it takes a bunch. The ratio I settled on is around 32:1 - 40:1, anywhere in that range. When measuring the oil I always err on the safe side hence the difference in ratios.
The engine has alot of port area in it and the offset powerhead allowed the engine to have a huge exhaust system starting under the cowling. A straight fore and aft facing powerhead would have had limitations right off the bat.
 

fl.graderman

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Status update:
Since my last post I made one final adjustment to the jackplate that lowered the anti cavitation plate to 1/4" below the keel of the boat and keeps it on the same plane.
There is very little if any stern squat at holeshot.
The boat goes from a dead stop to top speed in about 9 seconds.
My top speed varies between 26.7 and 27.6.
At a fully-rigged weight of 900 lbs, I am convinced that this boat is running as shallow as possible.
My motor is decarb'd, starts and runs perfect and max rpms don't go over 5850 rpms with my 12p stainless prop. And I'm now feeding her a 40:1 mix to keep it that way...
For me, a boat is a means to an end. The end being getting to the fish I want to catch, where I want to catch them. I believe this little boat is finally up to the task. It's taken about 4 months and a total cost of about $6800, but it's done. Now I can spend less time messing with it and more time fishing.

All that said...THREAD CLOSED!



2015 Tracker Grizzly 1448 MVX
1996 Evinrude 25hp 3 cylinder looper
 

fl.graderman

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I thought about it Sunday morning, but those darn seatrout wouldn't stop hitting my mirrolure long enough to pull out the camera. Oh well...I've had worse problems. LOL. Maybe next weekend...

2015 Tracker Grizzly 1448 MVX
1996 Evinrude 25hp 3 cylinder looper
 

fl.graderman

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I do have this video for now...
The bouncing you see isn't porpoising, it's me running over the waves created from my last pass. This was taken after the final jackplate adjustments.
https://youtu.be/Rm1s0xM5w5Q



2015 Tracker Grizzly 1448 MVX
1996 Evinrude 25hp 3 cylinder looper
 

HeavyHook

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Great video! That ride seems as smooth as can be - definitely nice seeing everything come together. Oh and Go Noles lol.
 

fl.graderman

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HeavyHook said:
Great video! That ride seems as smooth as can be - definitely nice seeing everything come together. Oh and Go Noles lol.
Yes I am very happy with it.
You had me right up until...Noles!

Gooooooo Gatoooors!!!!

2015 Tracker Grizzly 1448 MVX
1996 Evinrude 25hp 3 cylinder looper
 

surfman

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I just read the part about the addition of the 13p over the 12p and how it dropped rpms and performance seemed to be the same except when added weight, not sure if you decided to go 12 or 13 but I would go wit the 12, the 12 will give you better overall performance especially when you add weight, also you will see a noticeable decrease in fuel economy with the 13. basically the 13 is adding more load to the motor so unless you make it lighter and/or trim it up and want to only run for speed, go with the 12.
 

fl.graderman

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In the factory service manual it says the wot range is 5500-5800. With the 12p prop it runs up around 5850 to 5870 depending on load, wind, chop, etc.
I let my own OCD cause me to buy the 13p to try to lower the rpms, thinking the 50-70 rpms over may damage the powerhead.
I also didn't understand that the rule about rpm change per inch of pitch applies to larger V-6 engines and not our little 2 and 3 cylinders...
So...
The 12p is on the motor, the 13p is sold, my OCD is back under control and I have a really good performing little fishing boat.
When I bought this motor, it was supposed to get me on the water and last until I saved up enough pennies for a new 25 etec...
I'm tickled to death with the power this motor has and I have no plans for a new etec any time in the near future...
 

surfman

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That's great, something else that most people don't know but the max rpm is just a recommendation from the manufacturer to achieve the longest life and best all around performance however, there really is no max on 2 stroke motors, well of course you could rev it until it came apart but, the more rpms you generate the faster you are wearing out the motor basically. I have a buddy that runs a mercury 200 on his bass boat and he also runs a 27" pitch prop but the prop runs basically only 1/3 in the water at wot and his motor is turning 9000 rpms. It is rated from the factory at something like 6200. But he wants the thing to do 85 mph, and it does, not with me in it though. Anyway, long story short, the extra 50 to 100 rpms over the recommended won't hurt a darn thing and it is better that you can max it out than dog it, that is actually much worse for those engines.
 

Slough Runner

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Great thread. I'm in the midst of getting my boat setup also. We have the same motor except mine is a 1648mv. On my old boat I flew...this one not so much. I have a lot of additional weight though. Right now at wot I'm running 5,200 @ 21mph. Having the CMC trim and tilt helps but a new prop is the step I'm at now. I'm running an aluminum 3 blade 10 3/8 13 pitch. I gave the boat to a local prop guru and should hear back from him tomorrow. We will see. Reading thru your thread has helped a lot...trim tabs might be in my future as well.
 

fl.graderman

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If we have the same motor, I'd say your overpitched. My guess is a 10 1/8 x 12 pitch stainless or maybe even an 11 pitch aluminum would raise your rpms where they should be and get you on plane quicker. I'm sure your 1648 is heavier than my 1448 and the 13p was just too much pitch.

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Florida Franco

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I have a 30 hp merc 2 long shaft on a jack plate stroke on my 1448 and it hauls butt. The propeller cupping makes a big difference on holding on to water. If ventilation and slippage is a problem take your prop to a prop shop and add 1/2 cup and decrease one pitch.
 

thill

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When you installed the jack plate you also moved the motor back and up changing the center of gravity.
Hard to believe that few inches matters but it's weight on a lever. You may need to move weight foward in the boat like the battery, tools and cooler to compensate...
^^^This^^^ If anything, the Riptide and battery should improve things,

Also, most 18" transoms are made for a short shaft motor. I just went through this same issue with a Tracker Sportsman 16, a similar boat.

I lived in Cape Canaveral during my teenage years. Spent a lot of time in the Banana River and port Canaveral. The fishing isn't what it used to be, but it's still pretty good.
 

Pappy

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Looking good and if you decide to take the plunge and start playing with engine height again you can probably switch to the 13" or at least try it or have the 12" modified with additional cup for the increases in engine height. I had to send mine off 2 or 3 times before diminishing returns set in.
 
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