View Full Version : Porpoising on a new Ranger 620???
08-23-2009, 01:55 PM
I have a new Ranger 620 with an Evenrude e-tech 250 hp. I am finding that I need to leave the trim down even after I plane off as the boat starts to porpoise?
Worse, I am wondering if the trim down is killing my gas mileage. I was up on Lake Vermillion the last two weeks and I put in $450.00 of gas. That is about 150 gallons of gas-No way I even came close to running even 150 miles which would give me 1 mile per gallon figuring about $3.00 a gallon!! (Resort fuel cost) I drive at 3500 RPM's most of the time.
Could that engine not been put on correctly by Ranger? What mileage per gallon would you expect out of the 250 e-tech HO? The motor is brand new (only had 25 hours on the engine going into this trip and I run nothing but XD100 oil.
08-23-2009, 02:42 PM
something is very wrong!
08-23-2009, 03:52 PM
I have the same setup.....are you running a Jackplate and a Raker 22p prop? In general you have to keep the trim down a bit when going slower but I can run on planeat 20mph with no issues. Because that model has a pretty big pad at the back it has some qualities of a bass style hull...fast up on plane and on the pad, keep the nose down at slower speeds or in the rough stuff.
Also that engine actually gets better mileage at higher RPM when you actually get up on the pad a bit and release the hull.
You may need to tweak your setup a bit...what are you seeing on the top end ????
08-23-2009, 04:15 PM
Turn you trip mileage on, you might be surprise how many miles you can run in a day on the V, have done a tank on a 620 in just over a day, but typically 2.5 day for 30-40 gallons of running, you get 3.5-4 mpg on big motors, so a 12 mile run oneway is 6 gallons, don't take long runnin and gunnin. Just spent a week on Eagle, and 2 nite on Vermillion and that was well over 300 miles
Couple of thoughts. Your boat is fairly heavy, so it shouldn't be that trim sensitive if it's rigged right in my opinion. Of course opinions are cheap, unlike boats/motors!
The first thing to check, is are you running the motor in the correct hole setting on the transom? When you are on plane running WOT the cavitation plate should be above the water, and if you are like me, running a jack plate, and have an I-Command set up telling you water pressure and temperature, you can raise that motor unbelievably far up and still maintain the 15 PSI required and be in the normal temp range. My 200 HO will absolutely scream when it is running in the sweet spot. If you are too low it is like plowing the water instead of pushing the boat over it and speed/RPM/fuel consumption will suffer greatly.
The second thing to check after you make sure it is at the right heigth on the transom is, do you have it propped right? If I rememmber correctly, it should be propped to run WOT at 5500-5600 RPM. If you aren't in that range, especially if you are running less RPM your gas an oil consumption will not be as good as it should be. I was told at a dealer that the gear ratios have changed on the big 2010 model year HO's with the L2 lower units, going from 1.85:1 to 1.58:1 and that the props they used to run are now way too much pitch.
If both those are OK one more possibility would be that you are running the wrong style prop for that boat. Different styles have more or less bow lift and that could be a contributing factor. I got an education and a half from DAH Propellers when I called them asking about a better prop for my rig.
Those are the first things I'd check because they are pretty easy to do with just a friend to help. If they all look OK you need to ask someone else with Ranger specific knowlege for help because I'm out of ideas.
Hope you get it squared away soon. These big E-TECs are sweet motors when they ar set up right.
08-23-2009, 07:46 PM
Bturg and Jem are right on the money. Your WOT should be in that 5500 rpm range. I have posted before about my setup a 6" Hydrodynamics Rapid Jack Magnum jackplate. It only costs about $260 or so and it ratchets up or down in 1/4" increments. This lets you really find the sweet spot. For normal running 3" below the pad is good for water in the 1'-2' waves you still get a good bite. If the water is calm with your motor you can go to 1" below because of your low water pickups on the nosecone (wish I had them on my '05 Johnson 150) with the motor up at that height your Ranger would really scream. If your looking to try props I have been running a 14 3/4 x 23" pitch Cabela's stainless for 3 yrs. and no problems for $299. If you run alot of rough water a four blade will do better it gets more bite across waves. For everyday and rough you can't beat a three blade. Try throttling up a bit when you start to porpoise sometimes that will take it out. In any event a jackplate will let you play around and increase your performance. Bass and walleye Boats explained it like this, your transom is a fulcrum the more weight behind the transom the more your bow is lifted prior to take off. It takes less power upon acceleration because more of the bow is already out of the water.
08-24-2009, 12:29 AM
Actually WOT on the 250HO is 5750RPM.............
08-24-2009, 06:30 AM
I have last year's 619 with a 225 Verado, but I can tell you that I spent the first half of last summer dealing with all sorts of those issues. The answer for me was going to a four-blade prop. You do lose a slight bit of top end (which is more than made up for with hole shot) you gain a whole lot of MPG, and you can trim up for maximum performance at even the mid ranges. I just totally hated the porpoising. Last, a lot of posts out there will point you to the possibility that your motor was mounted at the wrong height by the factory and those posts are very likely to lead you astray. My dealer was happy to allow me to play around with several props and that turned out to be the answer.
08-24-2009, 07:26 AM
With ALL due respect to Ranger, Evinrude, and the folks that are fortunate enough to own one. Not trying to step on toes here, but.........
1. How much did you pay for that rig??
2. Why, after paying that, should you have to go out and spend more dough on another prop right out of the box???
One would think that Ranger would have that all figured out before they sold you that particular rig. I would be just a tad bit upset with my Ranger/Evinrude dealer for that performance issue, something that should have been figured out from the start. "Those issues" and "tweaking"????? Sorry, I don't think that's right.
08-24-2009, 08:17 AM
That's not the fairest statement to make because there are so many variables that the boat mfg. can't know. How much fuel do you run around with, how much gear, how heavy and loaded more front or back, side to side. Are you a big fat guy who fishes with an even bigger partner or a skinny little snake that fishes alone. Maybe you're a walleye guy with a thousand pounds of lead and forty rods. I'm told that just the addition of a kicker motor on the transom can make a huge difference. Truthfully, I intend to install a hyd. jack plate on my next boat (more for shallow running applications) but I don't expect an entirely break-in free boat experience any more than I would with getting married and thinking the girl would not need a few adjustments.
08-24-2009, 01:12 PM
Sorta like buying a new 430 hp Corvette. And you find out that the factory tires really don't give you the traction out of the hole the way Goodrich TA's do. So go pop for a pair of those ($600)and you'll be set. After you spent what?
That, or get a really fat chick to ride with you.
Sounds about right to me.
08-24-2009, 06:03 PM
Maybe more info will help. I do have a 4 blade prop. Working with the dealer I decided to go with his set-up as he runs on the rough waters of Green Bay as I will. I put a Mercury Bravo I on the Evinrude e-tech( a cool $1,200)
I do have a kicker motor a 9.9 Johnson that I do not attach to the big engine unless I am trolling and want to be able to steer off the console steering wheel. Other wise I have a Panther lift and keep the motor up and tipped to the left. Once you get up you get no drag from that kicker.
I am not a monster 6'1" 225 and no real hogs in the boat but we do fish with 2 or 3 typically.
I am all ears..................
08-24-2009, 07:49 PM
Taylor I dug up a couple of Bass & Walleye to try and help. In Jan '08 they reviewed Joe Balog's Ranger 620 and he runs a Merc Pro Xs with a three blade 14 5/8 X 23 Tempest he fishes St. Claire and Erie alot, no jack plate. March '08 they review Ranger's Z520 with a 250 H.O. E-tec w/ 25" x14 5/8 BRP Raker, 8" Bob's Machine Shop Hydraulic. One common cure in other issues was transom wedges to get more negative trim on the motor, but for the same money you can get a jackplate to increase the depth of your trim angle and increase your water arc and angle at rest which helps holeshot and running attitude. I also experience some porpoising at times when I come down from WOT to about 3500. If there is small wake action it sometimes starts porpoising to correct this I trim down and throtle up just a bit it usually fixes it. I think your dealer should let you try a three blade 23"-25" pitch and see what that does first, especially when you dropped 12 large for their suggested prop. My dealer also suggested that I could upgrade my aluminum to a BRP for $500 but I decided to shop around that's when I decided to go with the Cabels's Prop for $299 I did't have much to lose, and my alum is a spare.
Hope this helps!
08-24-2009, 08:08 PM
My set up is a bit different, I am running a fixed 8" jackplate and have it set fairly high, this makes by boat run a bit looser and that is how I like it. Another big difference is I am running a 3 blade 22 Raker...the factory recomended prop. I understand that a 4 blade should give your more "lift" and in theory better rough water performance but lift is achieved but actually pulling the rear down ...lifting the bow. Your engine could also actually be to high if you are getting lots of porposing
Also I spent the day yesterday in a new 2010 (no real hull changes) with a 250 Yammi w/kicker and even with it set up pretty low that boat would hold steady plane at around 20mph no problem.
Try (borrow) a stock prop, that is what the factory recomends after all their testing and most of the Full bore factory Pros run something very close to that prop or that one itself...it should work.
Any other questions let me know, my setup works really well.
And guys setting up a high peformance rig does take a little more time unless you are happy with the factory's tested "mid-range" standard setup. So spend a little additional time and set up the boat for what YOU want it to do...or settle for average.
Setting up your boat to get the max out of it is part of buying one in my opinion. Every one is different, from the differences in the hull between two supposedly identical boats, to small differences in the way your motor runs, to weight distribution from the number and location of batteries to the number of anglers and as mentioned before the kicker.
The last boat I had, and Alumacraft 18.5'er with a 150HP Johnson would not porpoise, period! No matter how you trimmed it, how you loaded it, it just wouldn't porpoise. You could trim the motor out of the water while on plane and it just sat there. Lots of nose weight. Couldn't move the motor up or it wouldn't turn without cavatating with a three blade prop. It ran 52 mph the first time out with three guys in the boat. After I put on the bow trolling motor, two batteries, two anchors, the kicker motor, gas tank for the kicker, tackle boxes and other stuff it ran 42 mph. How can a manufacturer anticipate that? Changed props and was back up to 46 mph.
We had a 14' aluminum shallow "V" with an old Merc 10HP that porpoised at mid speeds but went like a rocket WOT. Ran a Mirrocraft deep "V" 14'er with an Evinrude 35HP that I need to throw a spare tire from my '75 Firebird (hell of a tow vehicle!) up front to keep the nose down when I ran it by myself. It was rated for a 35HP so why didn't it run great without the tire?
Had a Ranger 1600V with a 50 tiller that came alive after I moved the motor up about 2" on the transom. Should Ranger have known this ahead of time and made the transom 2" higher so I wouldn't have to bother? Not likely.
So like bturg said, do you want vanilla or do you want your rig to deliver all it can?
Well I hate to say it but you might be in for a long ride. I run a 621 with a 250 e tec. The prop I run is a 4 blade cyclone with a 21 inch pitch SS. The easiest way to check if the pitch is right is to open it up rpm's should be in the 5600 to 5700 range at top end. If your not close lower the pitch to a 19. I don't think ranger has a templet that they follow for mounting motors. This is where the troble can be. My friend runs the same boat and it is a flat out dog compared to what I'am running. ( Motor is set lower on the boat) Best thing to do is if your in the Green Bay area take it to the place you bought it and see if you can set up a day for prop testing. Most big places have a lot of spares around and will let you try them. Also one more thing and not trying to insult you here, but how much time do you have driving this style boat. When I switched from my 18 foot lund to my ranger there was a learning curve on driving it for sure. The curve got even bigger in rough water. It took a while but I got it down now. Feel free to email me and I will can let you know what we have tried already to fix my buddies boat. So far a mercury stainless prop has been the best but still not all that good. Might be a starting point for yours. Also working with a dealer to see if raising the motor will help. If I hear anything I will post.
08-25-2009, 07:35 AM
Understood, JEM. I suppose that some tweaking is necessary for the ultimate ride and performance. Good from the factory/marina, but much better after some time with the owner, (but more money.)
After years and years of snowmobiling I should understand it better. We could drop $7000. on a new triple 800 only to find out that it really came alive after another $500 and just a few clutching tweaks. But we still always wondered why the factory couldn't do that in the first place.
Ranger makes one hell of a boat, same with the E-Tec. I hope you find your answers Taylor and you get her dialed in. Sorry I can't help you much, I'm running an old 1990 Lund 16 and 50hp tiller. I really don't belong in the conversation. But maybe someday......... ;)
Northwind Mark, conversations on here are good. That's how we learn things, get new ideas, and get help from others that have gone through what we are experiencing. It never hurts to offer a different perspective.
I'll second the thoughts about the learning curve to drive a new higher horsepower rig. I still have a tendency to want to apply too much trim too quickly at lower speeds which gets me porpoising and looking like a rookie driver. Got spoiled with the last boat that was JEM-proof to drive. Give me another 15 years in this rig and I'll figure it out!
Taylor, please keep us informed on how you are doing when you try different things. Love to get feedback on how changes affect the way a rig runs.
08-25-2009, 09:47 AM
A few addition thoughts. My prevous boat was a Crestliner 1850 with a Yamaha 115 4-stroke. Worked liek a charm no porpoising at all. BUT everyone warned me that when I moved to this rig it would be a big jump and it has. When this boat got on plane the first time and jumped from 20 to 50 in a vapor I new I was in a whole new ball game. I really felt the porpoising was my doing at first but now I have had some really experienced drivers take it out and they are getting the same thing.
All out it does run at about 5700rpm and gets about 60 on the locator.
Normal running speed has been at about 3000 rpm. Gas mileage just seemed horrible. I put in 150 gallons and would be surprised if I even went 100 miles BUT i will figure it out as I had the hours checked before this trip and will get them rechecked again tommorow at the dealer I will mulitple the hours driven by 30 as that a was a good average speed 30 mph.
Love the feedback :D
08-25-2009, 01:24 PM
Just a thought, but don't you have a trip computer function on your GPS that tracks mileage? I reset mine before leaving the dock each day and when I return I know exactly how far I've gone.
08-25-2009, 08:51 PM
I have hummingbird this year. I had Lowrance in the past. I have not found the mileage trip on the Hummingbird.
08-26-2009, 07:24 AM
There is one on the Hbird I found it the other day. I think it was on the gps info page.
08-26-2009, 06:29 PM
Ok I found the triplog but not sure it will do much good. It looks like it records all movement of the boat including when youa re using the trolling motor. this has to be as it is saying my ave m.p.h is 3.8 m.p.h
Then you have statute and Nautical options????
08-26-2009, 09:42 PM
3.5 to 4 is about average for mileage under normal use actually.
Keep us posted if you try any setup changes. FYI my boat with the 22 raker does 65 GPS at 5750RPM with a full Muskie gear load...I have a LOT of gear....68mph light two person load.....so with a lower geared prop you should still see 60plus and have incredible holeshot/rough water performance as an attainable goal.
08-27-2009, 05:10 PM
WOW that is FLYYYYYYING!! Low 60's is plenty for me. I called Evinrude today and I might have come onto something. This trip we filled upt he livewell early on as we got into some walleyes. We kinda forgot about it and left it filled. They said that is about antoher 300lbs of weight in that back-end. That with the 4-12 volt batteries, 9.9 kicker three fishermen all in the back could have had an effect on the ride. I am going to leave that livewell empty next time out and see.
Also Vermillion can serve up some good wind on the main lake on the east end and we were playing in it all week. Some days good 4 footers and I have to be realistic that that will effect gas mileage.
Lot's of tweeks I can work on.
top water freak
08-27-2009, 06:49 PM
That is the difference. Full loaded on fuel and takle is alot but add the livewells and it changes all rangers big time. My Z20 is the same way,full fuel and the speed to stay on pad starts to go up from 28 mph to about 33-35. Add the livewells on that and it take twice as long to get on plane as empty on fuel and water.
08-31-2009, 06:37 PM
Ran it this weekend with the back livewell empty-HUGE difference!!!:7 :7
08-31-2009, 08:53 PM
Now think in terms of fuel tank levels affecting ride and performance.
If you know you will be in the rough stuff keep it full, the bow stays down and crushes the waves.....
The dock is in
09-01-2009, 12:20 AM
Isn't porposing usually due to too much weight in the rear of the boat? Worst I've seen is a Boston Whaler that had too high of a horsepower engine hanging on the back. Very dangerous-but fast. Ironically, aren't Crestliners are very common porposers, as the gas tank was under rear floor rather than midships on older models.
09-01-2009, 08:01 AM
>Now think in terms of fuel tank levels affecting ride and
>If you know you will be in the rough stuff keep it full, the
>bow stays down and crushes the waves.....
Bob's onto one of my morning rituals if the wind is going to blow ... I always fill the gas tank because, as Bob says, it crushes the waves, but it also helps with boat control (the bow sits just a little lower), and with your ability to last all day (the bow doesn't move as much so there's less bouncing for the trolling motor operator).
In really bad stuff, I also fill up the forward baitwell for even more weight in the front end.
A final tip -- to keep your livewell almost completely dry, turn the controls to "Recirculate" and leave them there until you want to pump water into the well.
09-01-2009, 07:29 PM
you think yo uknow a little about boats and then you get a new one. I am just thankful for all the suggestions others have already discovered with their Rangers.
I actually had a Crestliner 1850 before the Rnager and never had problems with it porpoising-now it was underppwered with a 115 h.p. vs. a max rating of 150 so that might have helped with a little less weight on the back end. The BIG difference is the performance of the 620 in high waves it is just a killer-I have yet to get wet and have been out in 4-5 footers. NEVER could do that in the Crestliner as nice a boat as that was.
09-01-2009, 08:31 PM
I just KNEW we would be able to help you out with the problem, Dan ..... :7
Glad you worked things out and congrats, that's one hell of a rig.
Now, bring on the fall hunt.