2001 135 Optimax may have seized

there is only 119 hours on it was cruizing down the lake from dock about a quarter mile and she just locked. Any suggestions before I pull plugs and check cylinders?

[staylor]

With kill switch pulled, can you turn the flywheel by hand thru one full revolution cycling all 6 pistons thru top dead center without noticing any strange tight spots where something is dragging? If you feel binding or dragging of parts, remove the drive belt that drives the air compresser for the fuel system that is driven by the flywheel. Try and turn the flywheel, belt tensioner pulley and compresser pulley one at a time to see what's stuck. If all seem to turn OK, then you may have blown one of the fuses and had the fuel system shut down- this will cause the engine to stop dead in its tracks. There is a single big main fuse that overrides everything, plus smaller fuses for each individual electrical component on the engine. There are cases where a wire has shorted from rubbing against the cowl- or the main wiring harness plug has loose pins- and this will cause the main power fuse or one of the smaller fuses to blow and cause instant shut down.
Doug

[REW]

Wally,
Pull the plugs and see if you can turn the flywheel by hand. If you have any issues at all in turning the flywheel with the plugs out, you can put a socket on the flywheel nut and see if the motor is bound up in one or both directions.

If so, then, use a video scope to check the interior of each cylinder through the spark plugs.

If your motor is locked up with the plugs all removed - you likely have a serious issue.

Good luck
REW

[REW]

Wally,
Since this is an optimax, it is a 2 stroke engine.
Was there oil in the oil tank and do you believe that the engine was getting adequate oil?

REW

p.s.
When you find what is going on, let us all know.

[tv4fish]

and she just locked

Wally - could you describe "locked" in a little more detail. When a multi-cylinder 2 stroke seizes, it usually does not just "lock" - it is more like an extreme "loss of power" or like someone turned off the ignition as the pistons begin to stick in the cylinder walls.

Thanks all for your insight and knowledge going to check compressor then cylinders yes had ample oil in both containers.It let out a screech and engine instantly shut down.I hope its just compressor.I will find out tommorrow,again thanks so much for your input.

[jopes]

could be a lower unit failure as well. Fishing line around the prop shaft can cause the lower unit to loose it's oil.

[winchester jack]

I had a similar thing happen with mine, sounded awfull. The spring for my belt tensioner broke, therefore the air compressor couldn't do it's job.

[REW]

And the problem is??

[Burr]

With the optimax, this type of symtoms are very often compressor related, rather than piston or lower unit related. However, all of them are suspect in a diagnosis.

Based on age of motor, not hours, it would not surprise me to find out there is a compressor issue to be addressed.