Successful tilt motor surgery

After reading some kick-*** posts, I took on the job of cleaning the tilt motor brushes on a Mariner 150 HP 1991 model outboard. It<br />is definitly easier said than done!<br /><br />The tap with a hammer while holding the switch is a great DIAGNOSTIC for the sticking brushes, but don't kid yourself that it will fix it. Any motor brushes that stick once will keep doing sticking.<br /><br />I'm a mechanic, but boats are new for me, and I've never removed this part before. The removal of the side bracket that holds the whole freaking engine up was definitly a must-do, just like the posts said. That doesn't mean it's easy. Use a impact wrench on LOW setting. I twisted off one of the three side bolts on HIGH. You have to jack the whole engine weight up and down to get the transom bolts at the sweet spot where they'll come out. Lots of corrosion here made it hard to tell what's keeping 'em from turning. Good luck in removing all the wire clamps, once agian salt water holds em tight. I use a hand-held impact driver and phillips bit, the kind you smack with a hammer. Only rounded one of those out, had to cut the head off with the Dremel. Fully loosen the steering cable that goes thru the tube and pull it out a couple inches. If you have the twin steering cables you have to release it on the other end first too. Then remove the large locking nut. The bracket should come out and swing up now unless you missed a bolt. Disconnect the wires by the starter and pull the cable all the way out thru every hole leading to the motor top. <br /><br />The little motor is held in by what seems to be two 6mm allen head bolts. Use a ratchet drive if you have it, they're awfully long. A post stated you want to gently persuade the motor up and out, good advice, it's tender stuff in there.<br /><br />At this point it's off to the work bench, DO NOT try this on top of the driveway, you'll lose it.<br /><br />MARK THE ALIGNMENT OF THE TOP, BOTTOM AND CENTER CASINGS WITH A METAL FILE! When you reassemble you'll know which way everything was. The four phillips screws on top had to come with the hand impact once again (What's with the Phillips crap everywhere?). Chuck the motor in a vise with plenty of padding on the jaws to do it. Take the bottom off first. Try to save the little rubber o-ring as you seperate it. On mine at least two tablespoons of ground up metal fell out at this point. Wow! Slide the motor rotating assembly (the rotor) out this end. Remove the wire bracket on top and put some grease on the cable, the cover has to be able to slide easily up the cable now. Carefully work the top off, and make damm sure it is sliding up the cable or you rip the wires out the assembly and ruin it.<br /><br />Hello, there's the famous brushes staring you in the face! Each of the four need to slide in and out out their little brass sleeves with the slighest push. On mine three of four were jammed real tight. Here's where you break out your favorite electrical cleaner spray and go to town on the top, rotor, brushes, windings (stator) and bottom. Try not to get any thing in the hydraulic fluid section, try holding that upside down while cleaning. An old toothbrush works well on all this.<br /><br />At point just do everything above in reverse! Personnally, I tested the little sucker breifly, right after I put the two allen bolts back in, then I finished the job.<br /><br />Hope this helps anyone needing a little more detail on this. I have 25 years of mechanical experiance and It took me about three hours, non-stop. It's an easy job to screw up if you're not patient, that's how I twisted off the side bolt. I think someone said this job runs about $800, with a new tilt motor, at a boat shop.