Overpowered by 65 hp

[prcacowboy08]

I bought a 1980 hpv-175 Glastron bass boat that is rated for a 175 hp motor but it has a 235 hp johnson. They were using it all last season and said it did fine until the transom gave out...probably due to extra weight of the motor but I am rebuilding the transom and I am going to run 3 extra knees to help support the weight of the motor since the transom does not run into the wings of the boat it is just a center transom. My question is how is the extra 65 hp going to effect this boat I would only operate it at a safe speed heck it is a fishing boat I can get there with half throttle without killing myself more importantly someone else. I know the legal issues of overpowering I am more concerned with the performance of the boat with this much hp because the legal issues wouldonly be a concern if I was out there trying to race someone else which I am not into so safe boating is more my style.

 

[Antares2000]

Re: Overpowered by 65 hp

start thinking of other people...my god you really feel safe blasting around at 80+mph?
think of others

 

[marine4003]

Re: Overpowered by 65 hp

More that likely the transom gave out due to rot than weight, there's not much difference between the 2 motors. As for handling..with the extra HP the boat will become extremely unstable at high speeds, hulls are designed to match motors, along with weight,fuel tank location ect..all these factors are taken into account when a hp rating is determined, thats why a 17' bass boat can have a 250hp hanging off the rear,but a 17' bowrider 's max suggested hp might be 115hp..its all design. so, be careful, and know the boat,know its limitations, if it feels squirley at 45..then its dangerous at 60. deadly at 70.

 

[56 rude]

Re: Overpowered by 65 hp

start thinking of other people...my god you really feel safe blasting around at 80+mph?
think of others

nowheres in his post does he come off as a unsafe person to me ,where did you get the impression that he wants to go 80 plus?

 

[prcacowboy08]

Re: Overpowered by 65 hp

Ok sounds good guys I think I will watch it for awhile at slow speeds to see how it does and judge my performance from that. And antares2000 I don't think you really read the thread that well ...if you had you would have seen that others safety is my main worry and utmost importance to me.

 

[Nico2112]

Re: Overpowered by 65 hp

I really can't say about the HP you're talking about, but I for sure know this, early 80's, Johnson Javelin 85HP used the same block and weighted the same as the Javelin 115HP.

I have a 2009 Yamaha Four stroke 75HP, and it has the same exact block as the 90HP, and weighs the same.

With that in mind, I just browsed Evinrude, Mercury and Yamaha specs for motors similar to your Johnson 235, and I got the following results:

Evinrude E-Tec 2 stroke
E 175 DCX 433 lbs
E 225 DCX 518 lbs

Mercury Optimax 2 stroke
175 Pro XS 431 lbs
225 Pro XS 505 lbs

Yamaha V Max 2 stroke
175 2.6L VMax 468 lbs
225 3.3L VMax 539 lbs

It seems that with larger engines, the weight difference is more than with midrange engines.

Definately, reinforcing the transom would be a smart move.

Happy boating

 

[JB]

Re: Overpowered by 65 hp

Weight is not the problem. Thrust and torque are the problems and they affect the whole boat, not just the transom.

When you are done with the transom I suggest that you put a 150 or 175 on her.

 

[jay_merrill]

Re: Overpowered by 65 hp

Actually, the idea that you will only have problems with an overpowered boat if you are "hotrodding," is a bad one. If you get in an accident for any reason (your fault or someone else's), having a motor on the boat that is larger than what it is rated for, can become a serious liability issue. It may also be cause for your insurer to refuse coverage.

Lots of people overpower boats, but unfortunately, lots of them also pay dearly for that lack of judgement in the end.

I'm with JB on this one - lose the big motor.

 

[TheWoodCrafter]

Re: Overpowered by 65 hp

If you get in an accident for any reason (your fault or someone else's), having a motor on the boat that is larger than what it is rated for, can become a serious liability issue. It may also be cause for your insurer to refuse coverage.

I have seen this said many times on the forum.
It is always a good idea to safe rather than sorry but has anybody seen this happen?
Does an insurance company really send an adjuster out and look at the manufacturers tag on the boat to see the HP rating?
What if the boat is old enough where it does not have a tag?
Then refuse the claim? Come on.
This used to be done all the time in cars with no problems that I can remember.
This whole thing sounds like an "urban myth" to me.

 

[marine4003]

Re: Overpowered by 65 hp

I have seen this said many times on the forum.
It is always a good idea to safe rather than sorry but has anybody seen this happen?
Does an insurance company really send an adjuster out and look at the manufacturers tag on the boat to see the HP rating?
What if the boat is old enough where it does not have a tag?
Then refuse the claim? Come on.
This used to be done all the time in cars with no problems that I can remember.
This whole thing sounds like an "urban myth" to me.

Yup, My Scarab's maintenance is handled by a local Marine high performance shop, these guys do nothing more than make boats go FAST, and occasionally there are accidents,and due to the high cost of these boats repair costs are high,so adjusters constantly inspect the boats...never has a claim been denied due to overpowering,its like teenagers on rice rockets,common sense... sometimes prevails...sometime doesn't.

 

[jay_merrill]

Re: Overpowered by 65 hp

Generally speaking, insurance companies look to avoid claims by finding things that were not intended when the policy was written. When a "go fast boat" is insured, it is insured as such and an appropriate premium os charged.

If the average boat is insured as such, but is then modified in a way that is generally considered to be unsafe, expecially if the consideration is that of a regulatory body such as the USCG, you can bet that they will try to get out of the claim.

 

[marine4003]

Re: Overpowered by 65 hp

Yes, if its considered a "go fast" most of these boats are not manufactured to be true go-fasts, what they are ..are sleeper's..typically v hulls with small 8's that get there power upped 50-100hp ..thru hull exhaust..bolster seats and fancy graphics & paint..there a poor mans go-fast.Again, never have claims been denied.

 

[H20Rat]

Re: Overpowered by 65 hp

**deleted**

 

[TheWoodCrafter]

Re: Overpowered by 65 hp

Well there you have it.

Urban myth, just what I thought.
Propagated by thoughs that are afraid of 'go fast' boats.

 

[SuzukiChopper]

Re: Overpowered by 65 hp

Sell the motor you have now, find the appropriate one and pocket the extra cash you'll make off the sale. You have already said that you won't need that much power to get from spot to spot to fish. Better safe then sorry and a chance to make a little cash to re-coup the transom fix.

 

[prcacowboy08]

Re: Overpowered by 65 hp

Lol thanks guys but again I am not worried about the insurance or legal aspect of this topic just if the boat itself can handle the extra 65 hp that has been put on it. I can handle the boat at a lower speed where it is still stable but can the boat handle the motor.

 

[RollingWanderer]

Re: Overpowered by 65 hp

...but can the boat handle the motor.

I don't think anyone knows the answer to that question...I doubt that anyone here has had that particular boat/motor/rebuilt transom combination ever. The best you are gonna get is speculation and personal opinion.

With that being said here's my .02...

Rebuild the transom reinforced, stick the motor back on there, use the boat, keep an eye on things, work the boat speed up slowly and see how it goes. Get back to dock at the first sign of trouble if need be, otherwise go catch some fish.

 

[Home Cookin']

Re: Overpowered by 65 hp

the too-big motor already broke the transom once. Res ipsa loquitor. If it fails again and someone is hurt, you are dead meat my friend, and likely uninsured. Go read your policy.

 

[AtoZ]

Re: Overpowered by 65 hp

Be safe, call you insurance company and ask them, their opinion will carry much more weight than ours. Get it writing.

 

[Splat]

Re: Overpowered by 65 hp

as far as safety, that doesn't hold any water either. ANY boat can be dangerous when driven recklessly. A skilled captain with an overpowered boat will have no issues.

.

But then a skilled captain that knows his boats wouldn't be asking such a question would he?

Bill