boat listing at speed

Looking for a boat engineer who has experienced a heavy listing of craft underway. I have a 1986 21 ft Dixie blue fin walkaround offshore fisherman with a small cuddy and a hardtop. After several expensive repairs, I decided to replace my 150 hp v-6 Johnson with a new Honda 130 4 stroke. The boat has a 24 inch engine bracket mount standard from the factory since new. The dealer took off the Johnson, replaced it with an identical 25 " shaft Honda in the same mounting holes. The prop chosen was a solas 13 1/4 x 15 three blade aluminum as suggesteds in the Honda website for a nearly identical 22' Wellcraft W/A. Ever since the change, the faster I go, the more the boat lists starboard (Previously straight and true to 50 mph) The new motor weighs 100 lbs. more, but I removed a 75 lb. kicker making the weight to within 25 lbs.There are no trim tabs on the boat, but the motor tab has been adjusted. Even tried counter balancing with weights fore and port. The motor has been moved up and down 2-3 " yet the dealer, the manufacturer, and I cannot come up with with a plan. Any suggestions???

 

First thing i would do is put the 75lbs back where the kicker was and see if that makes any difference !!..
also what side was the kicker on originally??
does the boat float level at rest ?? measure chine to waterline at stern !!
don

 

I assume your motor is starndard rotation so it can't be the torque from the prop. Have you measured to make sure the motor is vertical? Even though it is in the same holes there could be some factory defect.

 

I posted this on the THT but here it goes again.

What is your top rpm at wot with the 15p?? Is the engine straight up and in the center? Is it possible the hull has trapped water somewhere on one side? Ifyou have a busted stringer on one side it can cause the hull bottom, on that side, to concave and suck it down. That almost sounds like whats going on based on your desription of how gross it is leaning and that would also get worse as you go faster or apply more power.

 

heavy listing

hawkeye:
I have not experienced near hi RPM as the listing made me cut back on speed. The new motor measured center, but I can only assume straight... will go out there and take new measurements later this week It is in the twenties in Michigan right now, so time outside is minimal. After placing a water meter on the hull, some water appears trapped in the aft starboard, but the manufacturer states that the hull was designed much like a Bostor Whaler (unsinkable) and even if I drilled 50 holes in the bottom, nothing would happen. I have looked at the hull carefully several times and found no hull deformation. Thanks for the input. Each time I hear from somebody, it gives me new insight as to what to look for and at. I have learned though that I can only make one correction at a time so as not to counter correct each move.

 

I would be looking for a crack or a small split in the hull some where on your starboard side .. if the hull is unsinkable ie filled with floatation under floor would suspect that water is in the floatation material, it was a common fault a few years ago when they first started putting floatation in under floors of hulls, must manufacturers dont do it now but i think there is some material that gives the same effect but will not absorb water!!!
don

 

Glad to see some of the THTers joined.

 

Don't know if that particular o/b has a torque-countering anode located on the cavitation plate, just aft of the prop..... But, if the steering is heavy in one direction or if you find that you're motor isn't in the dead ahead positon at speed, then I'd check the anode to make sure it's aligned correctly. Many people fit them angled in the wrong direction....

The others may be on the right track with the water in the hull, but I have my doubts. You say you've checked the boat running with various weights onboard. If you simply had water in one side, then putting weight on the other would counteract this. Also the boat would have a list at rest. And why would the boat suddenly develop cracks after fitting a new motor (unless your auxhillary was counter balancing the water of course...) Before you go off hunting for other problems, I'd eliminate the possibilities caused by changes you've made - ie removing the kicker and fitting the new donk.

 

I got another ? Hows the transom? Good ? on how it sits at rest. Just thinking a 100 lb more weight, plus being on a 24" bracket might be buckling the transom to one side. You can stand on the cav plate and bounce on it to see if the bracket is moving at the transom. Maybe lean on it side to side also. Conventional wisdom would point to the engine seeing that was the time it started but that extra 100 lbs may of been icing on the cake for the 17 year old transom. What worries me is you said it gets way worse the more throttle and cant even approch wot. Hope its not this or the stinger but something bad is wrong. I dont think the engine trim tab would cause that much balance problem but anything is possible. That trim tab is usally used to tune the steering tourqe to the normal operating trim of the engine. I never seen it make that much level difference. I just joined this board and it has a lot of good profesional advice from what I have seen so far.

 

Merick, Have you checked the engine rotation? They make them both ways for dual instalations. Will mentioned it above but you did not respond. Normal clockwise rotation would give a list to port at speed so most boats have the helm on the starboard side to counteract the engine torque. If your engine is reversed and your helm is on the starboard side, the list would be to starboard and amplified.

I'm doubting the problem has suddenly occured in the boat but we could all be on the wrong track.

 

Welcome to the forums Hawkeye - glad to have you here!

 

The only thing that doesn't make sense to me about the normal vs. counter rotation theory is that I wouldn't expect it to get so dramatically worse with speed...

If the prop torque had that great an effect on the overall port-to-starboard trim of the boat, even if it was the correct rotation wouldn't it be making the boat list the other way with speed (also to a point of concern... since the helm weight is a constant...) Maybe I am missing something though - maybe once it's a little off, it then doesn't take much force to throw it way off... I don't know since I'm not familiar with the boat in question at all, but something flexing with added force seems more likely to me.

 

I also wonder about the prop itself and if it's possible the new prop design might be a contributing factor ???

 

(that's probably a long long shot though)

 

Thanks for the feedback from all you guys. I went out to the boat yard this week; measured, removed as much counterbanance as possible( it is currently frozen solid in its Michigan location), and intend to take several steps one at a time when we have liquid water again. First, a moisture meter did see some water in the starboard side of the transom... the manufacturer claims that only a gallon or so could creep into the area because of the floatation logs integrated in the transom, however he did suggest a way to manually check this area. Second, the engine will be raised as much as possible (keeping all specifications is mind) to eliminate extra drag in the water. Third, the dealer is very helpful in trying other prop designs. Fourth, small trim tabs for running stability. The hull looks good, no deformation; the hull surface shows no cracks, there is some listing at rest, so the moisture is a paramount direction. Thanks again, let you know this spring how it went.