Not sitting on the bunks perfectly. Is this a problem?

[jet_boater_paul]

I never seem to be able to get my SX190 sitting on the bunks perfectly when pulling the boat out of the water. I just recently installed those trailer post guides, so I'm hoping I can tweak them to the point that there's near 0% chance of not getting the boat to sit on the bunks properly. Below are some pics of how my boat is currently sitting on the trailer. As you can see, I'm about an inch or so from perfect. The port side bunk is straddling the strake a bit. Is this bad / harmful for the boat? Also, from the pics, I have practically zero room for error the way the bunks are --- if I'm just 1/2" off or so, one of the bunks WILL be straddling a strake to some degree. It would seem to me to make more sense that the bunks should be situated to the outside more so that they can sit in between the 1st and 2nd strakes (they're spaced more apart such that the boat doesn't have to be 100% centered, and the bunks still won't be straddling a strake). But I can only assume this is how the trailer was setup from the factory for this boat, and this is how I see the bunks set up on all the Yamaha boats I've ever seen when searching the web for pics, so there must be a reason for this setup; am I wrong in thinking the bunks should be setup outward more?

 

[FX195]

Seems like you will need to adjust bunks. My bunks sit inside the strake , it's been like that since I purchased 2 years ago.

 

[mark_m]

I never seem to be able to get my SX190 sitting on the bunks perfectly when pulling the boat out of the water. I just recently installed those trailer post guides, so I'm hoping I can tweak them to the point that there's near 0% chance of not getting the boat to sit on the bunks properly. Below are some pics of how my boat is currently sitting on the trailer. As you can see, I'm about an inch or so from perfect. The port side bunk is straddling the strake a bit. Is this bad / harmful for the boat? Also, from the pics, I have practically zero room for error the way the bunks are --- if I'm just 1/2" off or so, one of the bunks WILL be straddling a strake to some degree. It would seem to me to make more sense that the bunks should be situated to the outside more so that they can sit in between the 1st and 2nd strakes (they're spaced more apart such that the boat doesn't have to be 100% centered, and the bunks still won't be straddling a strake). But I can only assume this is how the trailer was setup from the factory for this boat, and this is how I see the bunks set up on all the Yamaha boats I've ever seen when searching the web for pics, so there must be a reason for this setup; am I wrong in thinking the bunks should be setup outward more?

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I wouldn't sweat it.

However, when you bring it onto the trailer next time consider trying not to have the trailer dunked as deep. This should help center the boat better onto the trailer. If it doesn't, it appears you can move your bunks, which is cool. You could measure the offset and shift the bunk while the boat is in the water then experiment to get it centered accordingly.

 

[jamesk]

I don't think the strake should be sitting on the bunk, you will probably get different opinions on whether this is or is not a problem.
Just because it was set up by the factory, does not mean it's correct...someone could have made a mistake.
My SX210, I have very little room for error.
As long as I don't go too deep with the trailer and winch the boat up, it will sit pretty perfect.
If I am too deep with my trailer the boat tends to often not sit correctly on the bunks.
My boat sits like 1" above each side trailer fender so it is easy to see when I am not loaded straight.
I have 4 bunks, not sure if smaller ones only have 2? I think the 2 forward bunks I have help it center the boat on the trailer.

 

[Scoop]

I was concerned about this for my lift and was able to adjust the bunks through trial and error. Then I noticed a lot of stored boats in my neighborhood sitting on a single cinder block under the front center of the boat and figured I was overthinking it.

 

[212s]

Maybe someone with a 19' can show a pic of how their bunks are centered on the hull. My 21' has 4 bunks but the stern bunks leave about 1 inch of play to center between the strakes. I've heard of trailers not being setup correctly, so maybe yours just needs a tweak. I wouldn't want the weight of the boat sitting on the strakes, not sure it hurts anything, but it doesn't look right to me, and with the bunks inside the strakes, less chance of lateral movement.

I do as mentioned above and dunk the bunks to get them wet, then pull up the ramp a couple feet to get the fenders out of the water - this raises the bunks enough to help center the boat as I winch it up about 80%, then I back into the water another 2 feet and winch to 100%. This method centers perfectly each time.

 

[Canuckjetboater]

I never seem to be able to get my SX190 sitting on the bunks perfectly when pulling the boat out of the water. I just recently installed those trailer post guides, so I'm hoping I can tweak them to the point that there's near 0% chance of not getting the boat to sit on the bunks properly. Below are some pics of how my boat is currently sitting on the trailer. As you can see, I'm about an inch or so from perfect. The port side bunk is straddling the strake a bit. Is this bad / harmful for the boat? Also, from the pics, I have practically zero room for error the way the bunks are --- if I'm just 1/2" off or so, one of the bunks WILL be straddling a strake to some degree. It would seem to me to make more sense that the bunks should be situated to the outside more so that they can sit in between the 1st and 2nd strakes (they're spaced more apart such that the boat doesn't have to be 100% centered, and the bunks still won't be straddling a strake). But I can only assume this is how the trailer was setup from the factory for this boat, and this is how I see the bunks set up on all the Yamaha boats I've ever seen when searching the web for pics, so there must be a reason for this setup; am I wrong in thinking the bunks should be setup outward more?

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@jet_boater_paul .....I have never allowed a boat to sit on its strakes on a trailer. I would adjust the bunks to fit properly.

 

[jet_boater_paul]

Thanks for the responses. I will definitely adjust the bunks. Question though - on a 19 footer, which spot do you feel is a better placement of the bunks, A or B? (the bunks today are situated at position B, but A seems like it would provide better lateral stability...thoughts?)

 

[mark_m]

Thanks for the responses. I will definitely adjust the bunks. Question though - on a 19 footer, which spot do you feel is a better placement of the bunks, A or B? (the bunks today are situated at position B, but A seems like it would provide better lateral stability...thoughts?)

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What's the relationship to positioning of the bunk / chine on the starboard side? I'd just match the spacing on the port side and be done.

 

[Canuckjetboater]

Thanks for the responses. I will definitely adjust the bunks. Question though - on a 19 footer, which spot do you feel is a better placement of the bunks, A or B? (the bunks today are situated at position B, but A seems like it would provide better lateral stability...thoughts?)

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@jet_boater_paul .....I see if I can find any pictures of the bunks on our boat. I doubt you have to adjust much. You want both bunks to be equidistant on the trailer and keep the boat low but not so low that you risk hitting something on the trailer as it loads.

 

[Canuckjetboater]

Thanks for the responses. I will definitely adjust the bunks. Question though - on a 19 footer, which spot do you feel is a better placement of the bunks, A or B? (the bunks today are situated at position B, but A seems like it would provide better lateral stability...thoughts?)

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@jet_boater_paul .....so finally found a picture. My bunks (2020 SX195) are set - in the "B" position according to your diagram - just in down from where the hull starts to curve up into the chine. Hope this helps.

 

[212s]

@jet_boater_paul .....so finally found a picture. My bunks (2020 SX195) are set - in the "B" position according to your diagram - just in down from where the hull starts to curve up into the chine. Hope this helps.

That makes sense, near the weight bearing median center of gravity. My 212 has bunks close to the centerline at the stern to carry the weight of the engines, and bunks one set of strakes further out to carry the forward area weight. At first glance it looks like it's not quite balanced for cornering, but with a large percentage of the mass down around the engines, it makes sense.

 

[Canuckjetboater]

That makes sense, near the weight bearing median center of gravity. My 212 has bunks close to the centerline at the stern to carry the weight of the engines, and bunks one set of strakes further out to carry the forward area weight. At first glance it looks like it's not quite balanced for cornering, but with a large percentage of the mass down around the engines, it makes sense.

@212s .....well you guys with the bigger toys get the extra bunk!

 

[AZMark]

Thanks for the responses. I will definitely adjust the bunks. Question though - on a 19 footer, which spot do you feel is a better placement of the bunks, A or B? (the bunks today are situated at position B, but A seems like it would provide better lateral stability...thoughts?)

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Position A might let the front of your hull hit your trailer. Much more dead rise angle up front.

 

[TimW451]

I agree on B, A is too far out. Below is my SX240 on factory, non-adjustable MFI trailer.

 

[212s]

@212s .....well you guys with the bigger toys get the extra bunk!

@Canuckjetboater oh c'mon it's only 22 inches difference! The 24's are the bigger toys!

And I realized I got my bunk locations back-ass-ward earlier. The narrower bunks are for the front and I use those as the bow guides when loading. Duh, should look before I speak.
@TimW451 has it right.

 

[Canuckjetboater]

@Canuckjetboater oh c'mon it's only 22 inches difference! The 24's are the bigger toys!

And I realized I got my bunk locations back-ass-ward earlier. The narrower bunks are for the front and I use those as the bow guides when loading. Duh, should look before I speak.
@TimW451 has it right.

@212s ......only 22 inches you say?.............just sayin'

 

[212s]

@212s ......only 22 inches you say?.............just sayin'

It sounds bigger in inches! LOL