Ranger 340V achieving plane

[HoustonG]

Hello all, new member here. I recently bought a 1985 Ranger 340V with a Yamaha 150 of the same year. I took the boat to a marine mechanic before taking it out. The boat is well kept and the motor runs great. Compression was superb on all cylinders. Installed all new lower unit seals, new water pump, ne wplugs, primer bulb and fuel lines. My first time out I noticed the boat labored to get on plane so I suspected the prop as the issue. The prop is stainless but has no stampings whatsoever so i am unable to know the pitch. After doing some research I bought an Amita 4, 14 x 21p 4-blade prop. That only slightly improved the issue so I'm looking for advice. I have the motor trimmed down all the way and I give it full throttle taking off. The bow raises high and after probably a hundred feet or so (guessing) it finally attains plane and does fine. I had it out again yesterday and we had 15-20mph winds. I noticed that starting off into the wind the boat would often not achieve plane at all but just plowed along with the bow high. I realize this boat is on the small side at 16 1/2' but as for weight distribution, the rear livewellls and storage compartments are empty. I've watched the tach while trying to attain plane and it's 3000-3500. I don't care about speed as I'm a recreational fisherman perfectly happy to get to where I'm going at 30mph. Given the size and weight of this boat, I would expect 150hp to pop the boat up on plane rather quickly with a 21 pitch prop. Any advice/opinions?

[Rip Bass]

Does that prop have any vent holes on the barrel of the prop? Is it a large hub diameter or small? If it’s a large,the prop barrel will be about the same diameter as the lower unit,FYI. A 21 pitch should be about right if you can dial in the hole shot.

[NoZero]

Do RPMs come up while it is bow-high? Or does it feel like it is bogging and not attaining rpms?

I'll look and see what I have - Johnson GT150 - so different powerhead and gearcase... but I run a 4 blade Solas and it has been money for my 340V.

[HoustonG]

The prop hub is large, no exhaust vent holes. The rpms come up with the bow high.

[NoZero]

1) Do you have a Jackplate?2) What is your prop to pad measurement?3) Does it blow out easily on turns?


If it's spinning up to rpm but not coming on plane, you might need to lower your outboard -- otherwise, check and make sure that your outboard is lowering all the way down on trim. ... at full down trim, it should be tucked under a little bit on this hull.

[HoustonG]

It's getting in the 3000rpm range while attempting to get on plane. No jack plate. The trim is all the way down, but if it's down enough I guess I'm not sure. I'll look at that. I trim it down until it stops. Not sure about prop to pad measurement either. I've seen people reference the hull bottom to cavitation plate relation, but what should the prop to pad measurement be?

[unknown angler]

The 340 had a high transom,the engine can be mounted all the way down on the transom. As for prop pitch I ran a 24 Raker on a Johnson GT 150. Wasn't hard to get on plane accept in a heavy chop sometimes partner had to get in the front.

[HoustonG]

Thanks for all the input. I'm really starting to think there's a physical issue somewhere that I don't recognize. I'll check the height of the motor and how far in I'm able to trim it. If that all looks good I'm kicking around the idea of getting an SE sports 400 hydrofoil. Anyone have an opinion on if that would be of any help?

[Whiteboat]

I owned a 1985 340v with a Merc XR2. Either a 23" or 25" Lazer use to be the prop for that boat back in the '80's

[billnorman1]

Thanks for all the input. I'm really starting to think there's a physical issue somewhere that I don't recognize. I'll check the height of the motor and how far in I'm able to trim it. If that all looks good I'm kicking around the idea of getting an SE sports 400 hydrofoil. Anyone have an opinion on if that would be of any help?

Some it helps immensely, and you can pick up a whale tail cheap.

[BigFishSteve]

Don't drill holes in that plate too quickly. If you are new to bass boats, have a bass guy take a look at your equipment. Something will show. That combo should get on plane pretty easily, not riding with bow lift.

Could be as simple as a gouge on the front of the lower unit (or bottom of hull) giving you bubbles to prop and not biting well at take off.

[Nickk]

are you sure you're trimmed all the way down? Seems like a dumb question but when I got my boat(first bass boat) since the indicator was off I didn't have it "tucked" enough and struggled to get on plane until I trimmed AAAAAALLLL the way down

[HoustonG]

The boat mechanic that serviced the motor looked everything over and said all was good, but that was before I had it on the water so he wasn't looking for this issue. As for trimming down, I trim it down until it'll go no further.

[billnorman1]

The boat mechanic that serviced the motor looked everything over and said all was good, but that was before I had it on the water so he wasn't looking for this issue. As for trimming down, I trim it down until it'll go no further.

Keep us informed there is room left in my brain for more knowledge.

[johnfortier]

any chance you have a bunch of water in the bilge

[willwork4fish]

Once you get up on plane and the boat is "doing fine" what are your RPMs? There's a chance your control cables might not be giving you full throttle. I don't know what max RPMs are for an '85 but I had a '96 150 ProV that I had propped to turn 5800. Running a 25M it would pop my '96 Eyra right out of the water. Yours probably has 1.86 gears.

At WOT you should be able to turn over 5500 RPM. I would think more with a 21p.

[BigFishSteve]

Could be a water heavy boat. Many a nice boat got stored, nose down outside. I hate that so bad, my wife hate it too, as she will say it before me now, just to not hear me point it out.

Also, does that motor have a flip down "trailering" positioin bracket? A simple thing, but could keep you from trimming all the way down. Can you trim it all the way down and put a side view picture here?

[Lea]

At the top of theChampion boats forum here on BBC is a thread on how to measure prop to pad.

[HoustonG]

any chance you have a bunch of water in the bilge

No water, except when i shut it down to fast and it washes in. when that does happen i pump it out quickly.

[HoustonG]

Once you get up on plane and the boat is "doing fine" what are your RPMs? There's a chance your control cables might not be giving you full throttle. I don't know what max RPMs are for an '85 but I had a '96 150 ProV that I had propped to turn 5800. Running a 25M it would pop my '96 Eyra right out of the water. Yours probably has 1.86 gears.

At WOT you should be able to turn over 5500 RPM. I would think more with a 21p.

WOT is supposed to be 4500-5500. Honestly, when i'm on plane I haven't opened it up. I'm around 3000 with throttle left.