Friday, November 18, 2016

Failed Tilt Locks--Yamaha 9.9 High Thrust

Warning: If you don't own a PDQ catamaran this post is basically useless to you. I'll post something better tomorrow.

I like these engines. They are generally dependable, easy enough to work on, and deliver more thrust than anything in their class. But the engineering of the tilt lock mechanism is poor and is a familiar lament of PDQ owners. Fortunately, the cure is relatively painless, although it may seem crude. But crude, in the sense that it is simple, is a welcome thing to cruisers.

I suppose if the engine was mounted hanging off the back of a trailer boat it would be reasonable to keep it lubed in all the right places and to hose it off now and then. It would actually get to dry. But cooped up in the wells it gets corroded and stuck. Within 3 years I found myself having to use a winch handle to flip the tab down on the port side, and by now both the up and down motions are nearly locked. And when it finally locks, the engine will be stuck up or down and there's nothing you can do about it...

... Short of get in the water and fix it. Not as bad as it sounds. The first time this happened to me, nearly a decade ago, I had no idea what had happened and ended up tying the engine down with a rope for the rest of the cruise. Which actually worked fine, leading to this solution:
  • If the engine is stuck in the down position, remove the trim pin that the engine locks onto. Lift it up.
  • With pliers, remove the cotter pins and remove the latching mechanism and springs. No more lock.
  • Put the trim pin back in, if you took it out.
Now the engine will go up and down easily with the standard tackle, it just won't lock down, which means no reverse. Some owners have rigged up pulley systems, but I like to lift the covers and check for water flow, so I use something simple. A strap to hold the engine down.

The loop stabilizes the strap and keeps the pull handle from getting mangled.

  The attachment point in the back is a stainless bolt hanger, a rock climbing tool that makes for a cheap, strong, single bolt anchor. The bolt is existing.

Dead simple to make, it requires only a bit of webbing, a short lever strap, and a carabiner.
  • Make a loop from about 20 inches of 1-inch webbing and sew it to one end of the strap. About 20 ful stiches with #4 whipping twine will do. Trim the length of the strap  so that latch is in the center of the engine cover.
  • Sew a loop in the other and of the strap to attach the carabiner. In my case, the strap had a loop but it was too short, so I extend it with some line. I have the strap. Better, just sew the loop the right place.
  • Install a stainless bolt hanger (any climbing store or buy on-line) over the bolt at the back the dead-end the lifting line.
To install, slide the loop down the inside of the handle on the front of the motor, pull it forward, and thread the rest of the strap through it. Tighten down the resulting girth hitch/luggage tag and place the strap over the engine. clip to the bolt hanger. Tighten down for reverse, loose and lay off to the side for forward. If you are not going to use reverse, it need not be attached.


  1. Looks like your fix will last longer than the original mechanism.

  2. It did last time, lasting through two sets of used engines. Alas, there were some plain steel parts.