Re: What is the reason for limiting trim adjustment ?
Thanks, guys.<br />Now I'll tell you a spine-tingler from hell. The reason I asked the question was to validate what happened to us last Friday afternoon on Lake Lewisville, TX. This was only the 2nd time we'd had the boat out on the water since we'd bought it, due to weather and repairing the cooling system. (thermostat was shot and temp sender was shot) Although no one responded with the boat will be unstable if over-trimmed I believe it to be true, unless there is another reason that caused this.<br /> <br />We had been cruising around at different speeds for about 45 minutes, just driving the boat at different speeds and trim levels, to get a feel for her. The lake was glass! It's a blast to cruise on water that smooth and silky. We checked out some fishing spots (that used to take us an hour to get to in my buddy's party barge) and idled around some, generally just giving the boat some exercise, and familiarizing ourselves with the controls and feel of the boat. <br /><br />There were very few other craft on the lake. About a half mile away, a cabin cruiser crossed our path, and after fiddling around and inventorying lines and gear, we punched it and were cruising at 47mph (indicated, no GPS) with the outdrive trimmed for best speed as we approached the 3-minute- old wake of the cruiser at a perpendicular intercept. The lead ripples of the wake (looked like about ¼ inch or less high) immediately caused the boat to start porpoising. It bounced about three times in the next 4 seconds, going higher each time. On the third bounce, we were weightless for a second (scary) before the bow came back down into the main trough (6-8 inches) of the cruisers wake. The resulting effect was nearly fatal to both of us. <br /><br />The boat acted as though it were on a trampoline and lept into the sky. Somehow my buddy was able to flail and knock the throttle back while I was floating over a foot off the passenger seat. He likely saved our lives. The bow compartment cushions in front of me opened, and my buddy could see the gear in them (line, anchor, etc.) floating weightless for nearly 2 and a half seconds. (pure terror) Past the bow I could see only sky. The boat seemed to be completely out of the water and I could hear the motor whine, as though the prop was spinning with reduced resistance. I was completely at the mercy of the boat. The boat smacked down hard into the water with the engine winding down, and rebounded back up again to meet my buttocks still coming down. I thought it was over for both of us. The impact was shocking. I could not breathe from the pain in my back, and my buddy had seen me come down. He knew I was hurt. He was bleeding from his hand and I could see a smear of blood on his forehead. The engine had died and the silence was deafening. Somehow I managed to get enough breath to gasp check for water and gestured at the engine cover. I thought for sure the boat must be split in two and sinking. He pulled the cover and it was still dry. He wanted to get going again right away, but I couldnt take any movement until my back muscles relaxed a little, so we waited about 5 minutes for me to catch my breath and figure out a less painful position to sit in, restarted and cruised at half throttle back towards the ramp. The boat appeared to be undamaged and handled normally.<br /><br />On the way, we called a buddy who we had planned on picking up at the dock in about an hour to say we were heading in, and told him what happened. He used to race boats in CA. (not sure of the class, but he wore a parachute harness) His immediate response was that we must have been over-trimmed. As we cruised along, I trimmed the boat for best speed at half-throttle and at crossing the slightest disturbance in the water, the boat immediately started porpoising again. I immediately trimmed down and it stopped, but we were going slower. We drove back without further incident. I was laid up the rest of the night, and Im still on muscle-relaxers, pain pills and very stiff in the mornings. My buddy was sore the next day in his back and neck, and one of his knuckles was swollen. Ill try to arrange for X-Rays later this week, just to verify nothing is broken, crushed, ruptured or dislocated. <br /><br />The next afternoon we started looking at the trim controls. The Trim Limit Switch and Sender were both there, but the limit wouldnt kick in. With the help of the schematic, we found that someone had shorted together two leads with a spade bit connector, to defeat the limit switch. On top of that, the trim gauge was way off, indicating that the outdrive was still down even when it was raised past the side support ears of the transom assembly. We removed the shorting clip, re-installed the limit switch and set it to cut out at 6.5 inches from the center of the bolt on the trim cylinder back to the seal, per the manual, and adjusted the sender to bump up against the red on the gauge when it reached full travel (6.5 inches) before cut out.<br /><br />We both know we are lucky to be alive. Ive not tried to sugar- coat my impressions of what happened. The wake we crossed was negligible. Wed crossed bigger wakes earlier in the day at similar speeds, but hadnt been porpoising at the time. What we have been able to determine is that when the boat was trimmed for best speed, the outdrive was at an unsafe angle, and once in porpoising mode, the angle of the drive pushed the stern of the boat farther down on each subsequent bounce. The unfortunate, timely intercept of coming down from a porpoise bounce and meeting the 6-8 inch wake depression was enough to raise the bow 5-6 feet in the air while driving the stern down even deeper. The bow caught the air and the rebound launched the boat into it. <br /><br />I guess Im just looking for validation as to what caused this condition. <br />If it is just plain stupid to cross a 6-8 inch wake at 47 MPH in a 19-ft v-hull please just say so without calling me a dumbass, as I wont be doing it again anytime soon, regardless. Im just glad Im still alive to ask the question.<br />If the trim was the main culprit, Id like to know that Ive fixed the problem. <br />If Ive missed it completely and its something else, please help me learn what could have caused this, so I can avoid it.
