Improving 20Hp Performance

[nrensch]

I have a bass tracker pro crappie 175 with a 2015 20 HP mercury motor. The boat is used mainly in restricted HP lakes. The motor has a 10P alum. prop. Recommended rpm for this motor is 5400 to 6100 rpm. I am getting 5000 to 5100 rpm. Top speed is 14 mph based on GPS. The trim is set at the next to last hole. I also installed a Hydro foil SE200 on the motor which seems to help some to get stern up. How can I improve performance and speed to go faster and also get to the recommended factory rpm. Here is a video of my boat. Seems like the bow is too high. Located on YouTube .https://youtu.be/a56RDCQcfu4. Would a 4 blade prop help.

[carlm01]

I have a 2014 16ft lowe skorpion with a merc 20hp elpt and have no problem getting up on plane and it tops out at 23-25 mph just by the pic it doesn't sound like your engine is opening up fully could be the set up or the engine itself but it's new so I wouldn't mess with it .Get it into a good merc mechanic ..the other thing I would add is that my boat has the live well up forward with may help ?    Good luck

[Tim Kelly]

If that power pole is dragging in the water that won't be helping you. Might need to raise it up a bit. Looks like a lot of boat to get really planing well with a 20hp.

[S Hovanec]

An 8p prop will get you a couple hundred more RPMs. It may give you enough to get you on plane. My Honda 20 came with a 10p 4 blade aluminium and it was a dog. I got a 8p 3 blade SS and it made a big difference. That was on a 16' Sea Nymoh deep V tiller.

[Way2slow]

I don't have a clue what the boat should run, but I can say, the first thing you need is what was suggested, make sure the throttle is going fully open, and possibly the motor tested to make sure it's making full power. If it is, and you are currently running a 10" pitch prop, that prop is either damaged or way too much. The motors current rpm says you need an eight inch pitch, if they even make one that small for that motor.

I don't know what kind of weight you are running but from the looks of the way it's rigged and how much the motor is struggling to get going, you are pretty darn heavy. If the motor is making full power, I don't think you will see near the speeds the other poster is getting but a better prop will get it up and going a whole lot better. Also,, make sure you use a stainless prop. It definily make a difference.

[zachb34]

Not a mechanic or an expert by any means, but from my knowledge, all the 20 HP motors from the factory arr propped the same. The factory didn't know if it's going on a jon boat or a bigger heavier boat like yours. So in that case I would say you need a different prop, but since it's new go with having someone certified with Mercury to check everything else first, and make a judgement for your prop while it's on for your routine service anyway. Being a certified Mercury tech is crucial in case you ever need warranty repairs done later.

[WIGuide]

It looks like the smallest prop Mercury makes for it is a 10 pitch. You might be able to find one from another manufacturer who makes one smaller, or makes a stainless 10 pitch. If you can find one, a 4 blade might not be a bad option, but your prop options are going to be limited on a motor that small. Make sure you set your trim all the way down. Take the other advice and make sure the throttle is opening all the way up. Also after you try the previous two, start playing with the weight in the boat. See if you can move some weight from the back to the front as it will help with getting on plane. 

[Hi Salenity]

I would not use a 4 blade, you will have more luck/speed with a 3 blade.

[carlm01]

nrensch, I'm sure you've seen the youtube video of the Basstracker 165 w/merc 20 hp  thats hitting about 25 mph which is what my 16 lowe does , looking at your setup ,how much does the power pole set up weigh?  does that have a built in fuel tank and how much fuel is in it ? and it doesn't sound like it's wide open >>>  just my two cents...

[S Hovanec]

http://boatpropellers.iboats.com/Mercury-Outboard-Propellers/?pitch=8.00&chart=216&engine_id=673&cart_id=129397116

[nrensch]

Here is my plan. I took the power pole off (didn't like it anyhow), removed the hydro foil, also plan to move one of the 3 batteries up under my seat, get a remote 6 gal tank and empty the permanent 17 gal tank (it was half full), try to find a 8 pitch SS prop. All of this might just get the boat up on plane. Thanks for everyone's input.

[carlm01]

I think that should do it and if your still having problems get it checked out ....

[Way2slow]

You can not even begin to compare his Tracker 175 to your Lowe 16 and the speeds it should see in relation to yours. Ever heard the old expression, comparing apples to oranges. His boat is several hundred pounds heavier, plus the large hull is going to create a lot more drag.

He's already said he's running three TM batteries, and with the way he has gone with everything else, I would guess he's probably running one heavy a** 80# TM on the bow. Then the weight of the power poles etc. That's like comparing a plow horse to a quarter horse when it comes to speed.

Simply put, he has a lot of boat for a 20hp motor, and if it's a four stroke, that even makes things worse. He built himself a nice fishing platform, just sucks he had to restrict it to a 20hp motor to be able to use it where he fishes.

My suggestion would be to contact Bob Lipton, Performance Propellers in St Charles MO (636) 949-3121. If there is anyone in this country that can help you, this guy is a master in tuning props. A 20hp is probably not something he usually does but he might be able to help you. They can take 10 pitch SS props and take some of the pitch out, doubt he can take 2" out but he might be able to put something together that would add some giddy up go to it.

[carlm01]

Regardless of what he does with the prop he needs to lighten the boat up , You are correct his boat is about 400lbs heavier , I run 2 batteries not 3 and have a 6gl tank,But the guy with the 16.5 tracker is close to his boat and still manages to get up on plane and top out a 25 mph ... We don't know what his TM is , While I understand how someone would want a 17.5 boat ,it's not designed for a 20 hp no matter what you do. it's rated for 90  .....

[fishnkamp]

I built a Lowe Stinger 170 for the same type lakes.  First if you have a four stroke stop you are done for!  It will never get your boat on plane.  I had one and went back to a 2 stroke carbed engine.  These small Mercs have no trim on them. I started with a T&H trim plate (PT-35) installed the 2 stroke engine, changed to a smaller prop ( I apologize I do not remember what it was  because I sold that setup added a used 75HP and now fish tidal waters) and added a Stingray Junior. On lake Marburg (Hanover PA.) it would take off and level out with the trim quickly then reach 18 mph by gps.  The boat is a 1000lb hull.  I run a MK 70 Maxumm with three group 30 Cabelas AGM batteries and a tournament load of other gear.  I can not stress enough that you must have trim and tilt to make an underpowered boat work.

[BaitMonkey1984]

Couple thoughts. 1. Warning. 

 

If the motor is a 2015 make sure you break it in according to factory specs. Otherwise you risk serious damage to your motor.

 

I do not know your level of boating experience but I would certainly play with the trim, that bow should be getting down more. If that doesn't work I would do as WIguide suggested and try to make a change in weight distribution. First, try to eliminate unnecessary weight. Second, move weight to the front of the boat. Your situation is unique and you want to get the two down, so buck convention and put the heavier gear up front. I would try running higher octane gas and see if their is any noticeable increase in performance as well. Lastly, I would look at getting a jack plate that may give you the right angle to get the boat on plane. In fact, I can help you out with the jack plate funds- just let me take that power pole off your hands.