Boat won't plane

[bassmaster4]

Hey guys,

I'm having an issue with my boat, I can't get it to plane out, especially by myself in the boat when I hit the throttle the bow just points straight up and the transom gets dangerously low to the water. With a buddy sitting at the very front of the boat it does better but still rides a little high. I'm fairly new to boating so I have no clue what my problem could be. The boat is a 12 foot aluminium weighs about 200 lbs with a 2012 merc 9.9 four stroke on it. Anyone ever have this problem and if so what was the solution?

Thanks in Advance

Edited May 27, 2014 by bassmaster4

[Old Ironmaker]

Hey Bassmaster,

 

Is this a new to you boat? Has this done this before? For a small tinny with a 9.9 it's not uncommon. There really isn't much of any controls for planning out on your rig. I have seen it many times, even with a smaller guy. Had to put a concrete block and the anchor at the front of a 14 foot rental for a pal if he was solo and he didn't weigh 160. The pitch of the prop will effect the hole shot and how quick she comes up on plane. If you are accelerating slowly she may come up and stay up. Hammer her and see if it makes a difference, be careful, not alone out there when you try. If it never did this last year and you haven't gained a pile of weight someone else here will have a suggestion for you I'm sure. Let us know if this has happened last year like I said.

 

You just may have to weigh her down or loose some weight! That 4 stroke is heavy compared to an old 2 stroke. Is the 9.9 new? She may even be too heavy for a 200lb 12 footer.

 

Be careful about 5 years back I rented a pancake flat 12 foot Jon Boat and had an old 9.9 on her. My fishing partner( have to add fishing to partner nowadays my wife says) anyway he was nursing a self inflicted flu one morning and I headed out alone. No way she would come down at the bow. A gust of wind nearly flipped me over as water was coming in at the transom. I swore never again, came home and went out and bought my 19 foot deep V with a 115 Merc. At 225lbs. then that boat never had a chance. Would have been cheaper to loose 25 pounds, did that anyway.

 

Let us know if this something new happening.

Edited May 27, 2014 by Old Ironmaker

[lew]

You may just need to trim the bottom of the motor in a bit.

[Terry]

You may just need to trim the bottom of the motor in a bit.

yup

[Bernie]

Lower the engine down on the trim notches as the fellas have said.
A smaller propeller pitch will also help.

[DanD]

Trimmed in will drive the bow down

 

 

Trimmed out will pitch the bow up

 

 

Dan.

 

 

[lew]

Couple good illustrations there Dan, and once a boater finds the sweet spot somewhere in between those 2 adjustments he'll have the boat planing perfectly.

 

I knew a guy whose tinnie porpoised like crazy with him in the boat alone. I asked why he didn't adjust the trim and he said because the boat always bounced like that & he figured it was normal. I did the adjustment and he couldn't believe how the boat planed perfectly after that.

[DanD]

Kind of the same thing with a buddies boat; that thing pulled the tiller to starboard so bad that if he let go the boat would pitch hard to port.

The thing was dangerous anything above half throttle.

After some convincing he let me adjust the fin above the prop; only turned it maybe a 1/4 inch.

He couldn't believe it; wide open throttle and all he had to do is rest his hand on the tiller.

Simple adjustments that make a world of difference.

 

Dan.

[bassmaster4]

Hey Bassmaster,

 

Is this a new to you boat? Has this done this before? For a small tinny with a 9.9 it's not uncommon. There really isn't much of any controls for planning out on your rig. I have seen it many times, even with a smaller guy. Had to put a concrete block and the anchor at the front of a 14 foot rental for a pal if he was solo and he didn't weigh 160. The pitch of the prop will effect the hole shot and how quick she comes up on plane. If you are accelerating slowly she may come up and stay up. Hammer her and see if it makes a difference, be careful, not alone out there when you try. If it never did this last year and you haven't gained a pile of weight someone else here will have a suggestion for you I'm sure. Let us know if this has happened last year like I said.

 

You just may have to weigh her down or loose some weight! That 4 stroke is heavy compared to an old 2 stroke. Is the 9.9 new? She may even be too heavy for a 200lb 12 footer.

 

Be careful about 5 years back I rented a pancake flat 12 foot Jon Boat and had an old 9.9 on her. My fishing partner( have to add fishing to partner nowadays my wife says) anyway he was nursing a self inflicted flu one morning and I headed out alone. No way she would come down at the bow. A gust of wind nearly flipped me over as water was coming in at the transom. I swore never again, came home and went out and bought my 19 foot deep V with a 115 Merc. At 225lbs. then that boat never had a chance. Would have been cheaper to loose 25 pounds, did that anyway.

 

Let us know if this something new happening.

If I hammer it, it does the same thing haha. Thanks for the reply I'm really hoping the 4 stroke isn't too heavy it's about 85 lbs.

[bassmaster4]

As for trimming the engine down, I'm not sure exactly what is meant by that, I've lowered it all the way down it does the same. Thanks for the quick replies guys.

[bigbuck]

Iboats.com is a huge help if you are new to boating. The more specific you are as to your boat and motor, model number and or serial number someone there could probably tell you exactly how to fix your problem.

[Lape0019]

Everything stated here is a great start.

 

Trim the motor in as close to the transom as possible.

Change the pitch to 1 or 2 degrees lower than what is on there

Add weight to the bow of the boat.

 

85lbs for a 4 stroke shouldnt have that much of an affect on planing. There really isnt enough of a difference in weight between a 2 and 4 stroke at the 9.9 level to make that big of a difference that you wouldnt be able to solve it with 1 or all of the suggestions here.

[bow slayer]

you could also try a stringray hydrofoil,i have had good results with them

[lew]

Iboats.com is a huge help if you are new to boating. The more specific you are as to your boat and motor, model number and or serial number someone there could probably tell you exactly how to fix your problem.

 

Seemed to me he's already been told how to fix his problem by the members of THIS board Bruce

[Fisherpete]

Is it a long shaft on a short transom? Seen the results of that before...

[bassmaster4]

Thanks for all the input guys I've got a lot of things to try! I won't be able to get out in the boat this week but when I do ill post a follow up and hopefully a report or something. Fisherpete it's a short shaft.

Thanks again

[OhioFisherman]

My dad had a 16 foot Sylvan with a 25hp Johnson on it, the worst boat ever for one guy to try and fish out of. No amount of adjustment to the motor helped, anything much faster than a troll would send the bow skyward and block your vision.

 

A piece of carpet in the bow and a couple of hundred pounds of rocks helped, he even tried a whale tail on the motor without much success. It was a good boat though for inland electric motor only lakes.

[bigbuck]

Lew, everyone here was a big help. I suggest the other site because all the manuals, etc... are available there free of charge as well as the know how from a bunch of old hand techs to help with the inevitable problems that come up with boat ownership. If you do not know much about boats, a diagram specific to your motor is a big help.

[lew]

I was just joking with you Bruce and that was the reason for the smiley face...or whatever the heck you call those things >>>>>

[Terry]

There is a pin that needs to be removed and lowered to lower trim .. Job Done.

[bare foot wader]

how do you have your o/b setup now? pics would help explain with fewer words, it will be an easy adjustment, just need to know how you have it setup currently...I've used hydrofoils/whale tails before with results, but I'd try to adjust your setup before buying add on's

[bassmaster4]

The lowest I can tilt the motor.

 

 

 

How it's set up on my transom

 

 

 

A different angle.

 

Let me know if you need any more pictures.

Edited May 27, 2014 by bassmaster4

[bare foot wader]

so even with the trim pin in the lowest position, the bow still rises up high? I was kind of assuming it was setup further out, but it looks like you have it in the low position already

 

 

 

[davey buoy]

Full gas can in the front works wonders,anchor, etc.Longer hose may be needed,but under the front seats wasted room anyways.

[bassmaster4]

Okay, I think I'm onto something here I had this knob set at 3 the entire time.

 

 

After looking at this diagram it shows the settings for trim with each number. Is it likely this was my problem? I have it set now so I'll have to try but the motor looks the same angle wise at the back of the transom.

Edited May 27, 2014 by bassmaster4