Prop Won't Go into Gear

[nv5l]

I have a Yanmar with a similar transmission that stayed wet all the time due to leaks above it. No water got inside, but it did have a lot of rusted out bolts I had to replace. It was a mess...

The leaks were from both the exhaust hose coming off the mixing elbow and the cockpit drains. All fixed now...

Easy to diagnose by running the engine with the cover off or pouring a bucket of water into the cockpit. Water has to come from somewhere.

Hope this helps and is on topic...

[Pato]

The run dry impellers were designed for military use for when they gave to launch with motor running from a helicopter or from a moving vessel. It also had racers in mind that have ther boats airborne alot of the time. Most diesels won't over heat for 25/35 mins of run time with no raw water unless under load or is raw water cooled. Last week I ran a Detroit 6-71 for 35 min on land with no impeller for obvious reasons it did not even get warm it was fwc. If your engine is that hard to start it's probably time for a tune up or repower
Now to the OP does your gear have a cooler if so it's most likly your water in oil problem they fail all the time if you don't have a cooler you need to post a pic of engine room to see other posible sources of water making it's way into your gear Water also aids in a floating cone senerio Between water, oil and being over full is a perfect recipe for a floating cone. Hope this helps

[Pato]

Forgot to include that standerd impellers are either rubber or neoprene the high performance or HP impellers are silicone thus self lubricating giving them the dry run time with out meltdown or spinning a hub

[fsuhansell]

Finally got under the boat today and checked out the prop. The key had fallen out and the prop now turns free on the shaft. Looks like ill be pulling the boat a little earlier than expected. As for the water in the gearbox, I'm hoping I just hadn't gotten it all out the first time.

[S/V Antares]

Cool! Thanks for letting us know! It was a nail biting experience. Be sure to examine the prop keyway for wear. Glad you got back to the dock without harm.

[S/V Antares]

Ok... Thinking now after the jubilation...How did the Key get out with the prop still on? Close call?

[Captain Bill]

Originally Posted by fsuhansell

Finally got under the boat today and checked out the prop. The key had fallen out and the prop now turns free on the shaft. Looks like ill be pulling the boat a little earlier than expected. As for the water in the gearbox, I'm hoping I just hadn't gotten it all out the first time.

I am still a confused about how water got in the gearbox the first time. It is really difficult to get water into that type of gearbox even if it's submerged. The seals that keep the oil in also do a pretty good job of keeping the water out. There isn't any chance the gearbox is a KM3P instead of a KM2P is there. The 3p is water cooled and a leaky heat exchanger would explain the problem.

[S/V Antares]

Pato, The Globe impellers mentioned were Polyuerathane impregnated with oil and had reasonable dry time run. II have silicon cookware that goes 400 deg or better . I can olny suspect there are impellers made of this stuff but whee is it? Ahh mitilary secrets! LOL

[S/V Antares]

Folks, I would like to apologise "Globally" for my misspelling. Phat Phingers and a dull mind.....

[Pato]

SV Anteres I don't recall the name of the company making the silicone ones but they are cool. Installed some in a couple go fast boat and a couple in some navy rhib's

[Pato]

They are two to three times the price but you get what you pay for. I'll be looking into them again for my motors. I'll have the luckiest Volvo md3b and Suzuki motors

[fsuhansell]

Originally Posted by Captain Bill

I am still a confused about how water got in the gearbox the first time. It is really difficult to get water into that type of gearbox even if it's submerged. The seals that keep the oil in also do a pretty good job of keeping the water out. There isn't any chance the gearbox is a KM3P instead of a KM2P is there. The 3p is water cooled and a leaky heat exchanger would explain the problem.

When I bought the boat it had water damage from "sinking" in dry storage. The water level was a few inches above the sole so I'd blame that for the water in the gearbox. My only unknown now is how many times I'm going to have to change the oil to get all the water out. If only water was lighter than oil...

[four winds]

I have a Kanzaki v drive transmission which has a drain plug. Actually two plugs since it's a v drive. KM3V I think.

Yours doesn't have a drain plug?

Maybe with a siphon pump and a small diameter intake hose you can reach the bottom of the trans case and pump water first.

How did you drain the lube oil last time?

[GordMay]

Originally Posted by Domenic

... It's common to start engines that dicharge water through the exhaust with the water flow off. It takes more than a minute for an engine to even warm up.

I certainly wouldn’t endorse the idea, as a normal routine (“always”) starting procedure.

However, continued cranking of an engine can cause the muffler to fill with water, and back-flow into the engine (causing hydrostatic lock, or hydrolock*). Only shut off the water supply to an engine that won't start, and open the valve as soon as it does start.

* The water in the cylinders, being incompressible, locks up the motor so that it will not turn over. Other indicators are a rising oil level (from water finding its way into the crankcase), or creamy colored emulsified oil, the result of water being mixed with the oil, sometimes with beads of water, on the dipstick or inside the oil filler cap. In any event, you must get the water out of the cylinders (preferably immediately) prior to cranking.