My friend took me out on his boat last night, and he's had it for just at 2yrs. The engine has run flawlessly since he purchased it brand new, no troubles at all.<br /><br />On the way in to the dock last night, after taking off in the boat and getting on plane, he tried to trim the engine up, while at full throttle (running 52-5300rpm), to level the boat out. When he hits the trim switch, the TACH jumps to 6,000RPM, and tricks the motor into thinking it is over revving, and it cuts power to the motor (doesn't kill it, just bogs down). The 'limit' and 'check engine' light came on in his gauge.<br /><br />Now, when he hit the trim switch, the actual engine RPM wasn't increasing, it was just the TACH bouncing...the engine RPM stayed the same. <br /><br />I told him to try taking off, getting on a plane, and then lowering the throttle to about 4200 RPM, and THEN trimming the engine. It worked this time, because the tach only bounced to about 5000rpm, which didn't trick the engine into thinking it was over revving. Thus, the engine didn't kick into 'safe mode', or whatever suzuki calls it.<br /><br />Now, it definitely isn't a mechanical problem, the engine runs flawlessly at 100%...it is clearly electrical.<br /><br />He did say that he hasn't charged his battery in a while, and the lights on his gauges would dim considerably when he hit the trim switch. We were also out on the water for several hours with the NAV lights and the depth finder running, which probably sucked some juice out of the battery as well.<br /><br />Could the lack of juice to the tach cause it to get an altered reading, and bounce to 6000 rpm? Or does he have two wires touching somewhere in the Trim Circuit and the Tach Circuit?<br /><br />Any ideas? I obviously told him to be sure and re-charge his battery before he went out next time, and give it a try...but I just wanted to ask you all to help reassure him. He thinks he is going to be spending a few grand...worry wart.<br /><br />Thanks!<br />Shawn
