Yamahas And Negative Trim

[RogueAngler]

I recently bought a new 19' bayboat with a F115. The boat does not have trim tabs and I would prefer not to add them if possible. Given that, I am having trouble keeping the bow down in a chop. My last boat(18' bayboat/Johnson) had no trouble at keeping the bow down and was very responsive to trim.

I spoke with the dealer and he said that the reason that I am having trouble keeping the bow down is because the Yamahas do not have negative trim like the Johnsons. Is this true? I have never heard that but this is my first Yamaha. He suggested three things to correct the problem 1) transom wedges or 2) 4 blade prop or 3) trim tabs.

I have read threads about transom wedges and most people that have them say that they work well. However, that is usually on larger boats that already have tabs. Do you think that they would work in this situation? I also agree that a stern lifting prop may be benificial but I thought I would start with the wedges. Again, I have my reasons for not adding tabs and will not unless absolutly necessary.

Thanks in advance for you advice.

[Florida R227]

I think that depends on the angle of your transom. The Yamaha F250 on my Robalo has a decent bit of negative trim.

[HOTSPOT]

A larger diameter three blade stainless prop did wonders on my boat. Yamaha F200 on a 23 foot Sea Pro Bay Boat.

Went from a stock aluminum Yamaha 3 blade 19 pitch by 14 inch diameter to a Michigan Wheel Apollo II stainless steel 3 blade 19 pitch by 15 1/4 diameter.

Man what a difference out of the hole, keeps the bow down, handles better, and lower cruise RPMs.

Basically, this prop "bites" much better than what I had.

[Boatdood]

Your dealer is correct, they do have less negative trim than other brands. The angle of the transom comes into play, but more so with the Yamaha. If you are having an issue the most effective and least expensive approach is the transom wedge solution. With the wedges the trim tabs can then be used to level the load, and then if needed to raise the stern even more. A four blade prop may help but it sure does cost more than those wedges.

[kerno]

Easy fix: Add the wedges. They are cheap and they work. Make sure to seal the bolt holes well, so no water can get into the transom.

[RogueAngler]

Thanks for the replies. Looks like I'll be installing wedges. Kerno, the dealer will be doing the install so hopefully they will know how to properly seal the bolt holes.

[kerno]

They'll be using a sealer, but ask them to use 4200 instead of 5200. The difference is you can remove 4200, but 5200 requires things like C-4 to break it loose.