Stern Heavy Avon

[Jbcaptain]

Hello,
I just got my boat running good. a AVON 11ft with Unihelm and 20hp 4 stroke yamaha with foil attached.

It really gets the bow in the air when I floor it, but if I put a fat guy on the front 230lbs over the anchor hatch it plains perfectly. This is with my engine in the lowest position, it is a manual tilt and next time I will try other positions.

My question is if I can trim the boat differently to eliminate this. Or do I just need more weight in the front of the boat. I ordered an anchor and can start putting a heavy cooler in front as well.

[Brinormeg]

Not sure on your specific setup, but extra weight will use more fuel.

Perhaps a tiller extension could help balance the weight, generally up front towards the bow is better.Once on plane you can sit back a bit.

On my sib, and I've noticed many others, second whole is often better. But nothing to lose experimenting....just be careful not to plough into the waves too much.

[willk]

Originally Posted by Jbcaptain

My question is if I can trim the boat differently to eliminate this. Or do I just need more weight in the front of the boat. I ordered an anchor and can start putting a heavy cooler in front as well.

Keep the engine trimmed down. Move all weight forward, including fuel if you can - rig an extension if required. You might consider a new prop as well, maybe dropping pitch a few inches or possibly a 4 blader to get some lift at the stern...

[Fenlander]

I had to Google Unihelm. Where is that situated fore/aft... sounds like it could be moved up a bit towards the bow.

[Peter_C]

What brand of foil? Balanced correctly with a foil it should pass onto plane almost flat. Fuel tank and everything else that can be moved forward should be. Worse case the Unihelm may need to be moved forward. Would be nice if there was something like L-track to make it adjustable.

Nice little boat setup! I like the Unihelm concept. Great place to have a boat too.

[Easedalenovice]

Several of the replies you have received are from people who have not even bothered to read your OP. How an extension will help I know not. Does he mean a Tiller or House extension ����*♂️

Given you have a Unihelm which I presume you have fixed as far up front as possible for you other needs. You are generally only left with getting or adding as much weight up front.

[jeffstevens763@g]

Originally Posted by Jbcaptain

Hello,
I just got my boat running good. a AVON 11ft with Unihelm and 20hp 4 stroke yamaha with foil attached.

It really gets the bow in the air when I floor it, but if I put a fat guy on the front 230lbs over the anchor hatch it plains perfectly. This is with my engine in the lowest position, it is a manual tilt and next time I will try other positions.

My question is if I can trim the boat differently to eliminate this. Or do I just need more weight in the front of the boat. I ordered an anchor and can start putting a heavy cooler in front as well.

Trim out to the second hole and see that’s my go to position fuel kit up in the bow passengers can move to stern for a better ride and move forward whilst you get on the plane then drop back I’ve done sib builds and configurement changes thread which might help.

[willk]

Originally Posted by willk

Move all weight forward, including fuel if you can - rig an extension if required.

Originally Posted by Easedalenovice

Several of the replies you have received are from people who have not even bothered to read your OP. How an extension will help I know not. Does he mean a Tiller or House extension ����*♂️

Hmm, Fuel line extension perhaps - the clue is in the word fuel. Maybe you didn't bother to read carefully? Too busy picking nits

[Jbcaptain]

Speaking with someone more knowledgeable than I. Who runs a 14ft AB with a 40hp. He says these boats just ride like that, and they will pretty much always ride better with weight in the front.

I do not plan on moving the helm as it is bolted in and I do not want to create issues on a old boat. The fuel and battery is under the seat and strapped down, again I do not plan to move these things as they are secured.
I think if I have a cooler secured on the bow and maybe dive gear that will solve my issue. plus an anchor.

[Jbcaptain]

the foil is Yamaha brand. Here is some photos when I bought it

[Steve509926]

If those pictures are a true reflection of how you are running, then it definitely looks stern heavy - bow light.
I can understand why you wouldn't want to move the helm, however I do not understand why you wouldn't consider moving the fuel and battery when it will almost certainly cure your problem.

[jeffstevens763@g]

You will surprised how 1 hole back will change things on that set up to fine tune fill a container with water stick it in the bow try it then keep taking water out until it’s spot on then you know what kit you need to move.

[willk]

Originally Posted by Jbcaptain

Speaking with someone more knowledgeable than I. Who runs a 14ft AB with a 40hp. He says these boats just ride like that, and they will pretty much always ride better with weight in the front.
////The fuel and battery is under the seat and strapped down, again I do not plan to move these things as they are secured. ///.

OP - I've been posting here for 16 years and I have a good memory for post contents and trends. I also run a 14' boat with a 40hp. If I had a dollar for every time one of your compatriots posted an opening question about their 14' boat that runs bow up, I would have a 20-' boat with a 150hp

Heavy seats, fuel under the seat, fixed helm, battery all under the helm, couple of well upholstered crew in the stern. Stir as per Recipe for Disaster.

If you can't move the weight at the stern forwards then you will have to add a lot of weight to the bow. Remember that moving weight is twice as effective as adding it.

[Fenlander]

>>>My question is if I can trim the boat differently to eliminate this. Or do I just need more weight in the front of the boat. I ordered an anchor and can start putting a heavy cooler in front as well.

All I can say re the trim is it's individual to your setup and load... just try different positions.

And re weight as Willk says moving weight has double the effect... it seems mad to add weight to a boat that is already heavily laden for its size. Moving the fuel tank is so easy with an extended hose surely worth a try. You can get triangular tanks that would better fit the bow if a test proved it was a worthwhile move.

Also if your outboard still has the pull start in place then you could lose the battery, a modern 20hp 4-stroke should be an easy first time pull.

[Johno99]

I had the same problem with my previous boat, a Valiant 4.5. I placed two heavy ballast weights in the bottom of the anchor locker, made a world of difference. You could try a couple of concrete building blocks, they might take up too much room but maybe worth a try.

[Peter_C]

Originally Posted by Jbcaptain

I do not plan on moving the helm as it is bolted in and I do not want to create issues on a old boat.

The boat already has issues or you wouldn't be asking for advice. Filling a couple of holes is no big deal.

Originally Posted by Jbcaptain

The fuel and battery is under the seat and strapped down, again I do not plan to move these things as they are secured.

What kind of battery? If we are talking something like a Group 24 lead acid battery it would be good to switch to a lithium battery that weighs 1/10 as much. Why not move the fuel tank to the bow to test it? Even if it means buying a few meters of fuel line that is not a huge expense. (I moved my kicker fuel tank into the anchor locker to lessen my stern weight.) Heck you could get the boat running which will fill the float bowls, assuming it has a carb, shut it down and put the fuel tank in the bow. Then run a couple starts to see how it does. The fuel bowl will run the engine enough to do so.

Originally Posted by Jbcaptain

I think if I have a cooler secured on the bow and maybe dive gear that will solve my issue. plus an anchor.

Anchor, chain, and line in the bow locker will make a difference. If you are diving an unattended boat the anchor IS your lifeline. I prefer overkill for my ground tackle so I know my boat will be there.