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Hull Hop
- Thread starter Billykid
- Start date
skinnypockets
Well-known member
Check your motor mounts, may need to be re-torqued.
Prototype
Well-known member
Not knowing your rig or situation but 25 hours sounds real lite for this assuming you didn't climb a boulder and not willing to say?
Check for some backed out bolts or maybe even any seem if poly is seamed?
25 hours is like a lemon law except you have to figure out where the lemon is!
Bigger flag? Change the rigging? Marry a healthy swamp girl?
Unlimited but start back to new 25 hours ago in boat time.
Check for some backed out bolts or maybe even any seem if poly is seamed?
25 hours is like a lemon law except you have to figure out where the lemon is!
Bigger flag? Change the rigging? Marry a healthy swamp girl?
Unlimited but start back to new 25 hours ago in boat time.
Deano
Well-known member
First of all, do not read fast past sinnypockets' observation, this was my first thought as well. I've seen weird handling things happen after simply removing and remounting the engine, for completely unrelated reasons.
Next, I would definitely do as Curtis suggested and run a string line under the hull and identify the CAUSE of the difference before I went any further.
Is it possible it wasn't heated sufficiently when it was installed and is no longer tight on the hull, such as ladyblackwater eluded to? Seems doubtful, but running the string line will likely DISprove that possibility AND afford you piece of mind going forward. (If it IS wavy that may well be a different issue, needing it's own discussion or maybe just more bolts. On that note, it IS bolted and not screwed, correct?)
The other thing the string line will do, is show you definitively where the potentially needed jack(s) need to be located to best correct the situation. I sounds to me like a single jack (if it's positioned correctly) should resolve your issue given that it was a newer hull and this problem just started. Better to identify where first, and then place it correctly. A single jack in the right place can do more good than two or three just haphazardly placed. The string line will show you where that is, or at least, where it is most likely to be.
Understand that the porpoising that you're dealing with has to do with an other than "straight and flat" planing surface. While this may seem readily obvious, it pays to keep that specifically in mind and allows you to better weigh your two main options going forward. Each has pros and cons I suppose, and which is the better answer for you is easily determined by YOUR objective(s).
The first option is installing a hull jack. This is, in my opinion, the far better option. By doing this, you are CORRECTING the problem insomuch as you are restoring and/or maintaining the "straight and flat" planing surface you need. If the string line shows no abnormalities, then the hull may simply be flexing more than it should, and a jack could/would act is the needed stiffener. Additionally, by addressing the CAUSE, you are also preventing further degradation to the hull (especially if it is overly flexing and/or the trailer played any part). This is no doubt the PRO upside to taking this approach, is you are back to having and maintaining a new boat. The CONs or the downsides to this approach is that it is simply not as easy and may take a little longer.
The second option is installing a trim tab. This is, in my opinion, the far less desirable option. By doing this, you TREATING THE SYMPTOM and doing nothing to address the root CAUSE of the problem. The PRO upside to this choice is that it's quick and easy. The CONs or the downsides to this approach are to numerous for my liking. You will still be lacking the "straight and flat" planing surface you need. It is also worth noting that without treating the CAUSE, it is most likely to continue getting worse over time. This can and will allow a new glass hull, to exhibit performance degradation at a greatly accelerated rate. What I mean there, is that you don't want to end up with a five year old hull that performs like it has been beat on for twenty years. While a trim tab can correct the hopping problem you have in the water, when you are running dry, it will require more power to accomplish the same task because you still don't have the "straight and flat" running surface you need. Whether the increased resistance ends up being fore or aft, it will requiring more power to do the same thing, which will inevitably amount to more wear on everything; the hull, the poly, the rigging, the engine. It is also worth considering the overhead that goes with running a trim tab. Remembering to put it up coming out of the water is something that will become second nature over time (so they say) but you see tracks in the sand all over where somebody didn't remember. The sand gives/moves and this doesn't create an immediate issue. What about when you have to simply slide over a log or you catch a buried rock while sliding dry sideways ? Was your transom built in such a fashion to bear the weight of the whole boat/engine on a couple of bolts? Maybe yours was, but I've repaired many, many transoms that were not.
I am obviously not a big fan of slapping on a trim tab and calling it fixed. Now you know a good part of why. It simply makes more sense to me, to correct the cause than to treat the symptom. On some old beater hulls it can make more sense simply because of everything required to be corrected at that point. On a new, or near new hull I wouldn't do it for the reasons stated.
Naturally, these are simply my opinions and may be worth no more to you than you paid for them.
For whoever feels that way, I apologize for being so long winded; that was in no way my intent coming out of the gate.
Next, I would definitely do as Curtis suggested and run a string line under the hull and identify the CAUSE of the difference before I went any further.
Is it possible it wasn't heated sufficiently when it was installed and is no longer tight on the hull, such as ladyblackwater eluded to? Seems doubtful, but running the string line will likely DISprove that possibility AND afford you piece of mind going forward. (If it IS wavy that may well be a different issue, needing it's own discussion or maybe just more bolts. On that note, it IS bolted and not screwed, correct?)
The other thing the string line will do, is show you definitively where the potentially needed jack(s) need to be located to best correct the situation. I sounds to me like a single jack (if it's positioned correctly) should resolve your issue given that it was a newer hull and this problem just started. Better to identify where first, and then place it correctly. A single jack in the right place can do more good than two or three just haphazardly placed. The string line will show you where that is, or at least, where it is most likely to be.
Understand that the porpoising that you're dealing with has to do with an other than "straight and flat" planing surface. While this may seem readily obvious, it pays to keep that specifically in mind and allows you to better weigh your two main options going forward. Each has pros and cons I suppose, and which is the better answer for you is easily determined by YOUR objective(s).
The first option is installing a hull jack. This is, in my opinion, the far better option. By doing this, you are CORRECTING the problem insomuch as you are restoring and/or maintaining the "straight and flat" planing surface you need. If the string line shows no abnormalities, then the hull may simply be flexing more than it should, and a jack could/would act is the needed stiffener. Additionally, by addressing the CAUSE, you are also preventing further degradation to the hull (especially if it is overly flexing and/or the trailer played any part). This is no doubt the PRO upside to taking this approach, is you are back to having and maintaining a new boat. The CONs or the downsides to this approach is that it is simply not as easy and may take a little longer.
The second option is installing a trim tab. This is, in my opinion, the far less desirable option. By doing this, you TREATING THE SYMPTOM and doing nothing to address the root CAUSE of the problem. The PRO upside to this choice is that it's quick and easy. The CONs or the downsides to this approach are to numerous for my liking. You will still be lacking the "straight and flat" planing surface you need. It is also worth noting that without treating the CAUSE, it is most likely to continue getting worse over time. This can and will allow a new glass hull, to exhibit performance degradation at a greatly accelerated rate. What I mean there, is that you don't want to end up with a five year old hull that performs like it has been beat on for twenty years. While a trim tab can correct the hopping problem you have in the water, when you are running dry, it will require more power to accomplish the same task because you still don't have the "straight and flat" running surface you need. Whether the increased resistance ends up being fore or aft, it will requiring more power to do the same thing, which will inevitably amount to more wear on everything; the hull, the poly, the rigging, the engine. It is also worth considering the overhead that goes with running a trim tab. Remembering to put it up coming out of the water is something that will become second nature over time (so they say) but you see tracks in the sand all over where somebody didn't remember. The sand gives/moves and this doesn't create an immediate issue. What about when you have to simply slide over a log or you catch a buried rock while sliding dry sideways ? Was your transom built in such a fashion to bear the weight of the whole boat/engine on a couple of bolts? Maybe yours was, but I've repaired many, many transoms that were not.
I am obviously not a big fan of slapping on a trim tab and calling it fixed. Now you know a good part of why. It simply makes more sense to me, to correct the cause than to treat the symptom. On some old beater hulls it can make more sense simply because of everything required to be corrected at that point. On a new, or near new hull I wouldn't do it for the reasons stated.
Naturally, these are simply my opinions and may be worth no more to you than you paid for them.
For whoever feels that way, I apologize for being so long winded; that was in no way my intent coming out of the gate.
Deano
Well-known member
LBW, re-reading that I see that I did a less than stellar job of proofreading the beginning of that post. We are in complete agreement.
When I changed some wording there before I posted, I evidently omitted part of what should have stayed and I missed it.
The line that reads . . .
"Seems doubtful, but running the string line will likely DISprove that possibility AND afford you piece of mind going forward."
Should have read . . .
It may seem doubtful, but running a string line will likely disprove OR confirm that possibility AND afford you piece of mind going forward.
I didn't mean to imply that it was doubtful to us, but rather it may seem doubtful to him. Confirming it for himself, would make that scenario more believable. The couple instances I've seen weren't so obvious so as to be that readily visible to the naked eye. I have been spared that outcome, so would not be the best one to speak about making corrections for that scenario.
This is why I elaborated more to the other two possibilities. Those being jacks (which aren't all bad) and trim tabs (which to me, are).
It readily appears that we are all in agreement about trim tabs being an undesirable band-aid.
When I changed some wording there before I posted, I evidently omitted part of what should have stayed and I missed it.
The line that reads . . .
"Seems doubtful, but running the string line will likely DISprove that possibility AND afford you piece of mind going forward."
Should have read . . .
It may seem doubtful, but running a string line will likely disprove OR confirm that possibility AND afford you piece of mind going forward.
I didn't mean to imply that it was doubtful to us, but rather it may seem doubtful to him. Confirming it for himself, would make that scenario more believable. The couple instances I've seen weren't so obvious so as to be that readily visible to the naked eye. I have been spared that outcome, so would not be the best one to speak about making corrections for that scenario.
This is why I elaborated more to the other two possibilities. Those being jacks (which aren't all bad) and trim tabs (which to me, are).
It readily appears that we are all in agreement about trim tabs being an undesirable band-aid.
mixedbag
Well-known member
There is nothing wrong with having a trim tab, it's like having 4 wheel drive , there when you need it. Trim tabs were designed to increase the performance of a variety of watercraft. If I add 10lbs more of ice to my cooler, or the wind blows from a different direction, my boat, which rides flat, will skip a little in deep water. Just don't forget to put the tab up after use!