Raw water intake blockage

[rkgdmd]

Does your boat sit where people could freely mess with it?

That's interesting Julian. It's stored on my property on davits. I suppose it's possible, but very unlikely. I have some pretty protective neighbors.

 

[rkgdmd]

I wonder about an independent shop like this,
http://keywest-jetski.com/repairs/

We're headed home Saturday @Scottintexas . Tomorrow I have to pull the boat out and clean it up. Just ran out of time this trip...but thanks to you I'm pretty confident we have the problem solved. The technician I spoke with at Riva said there is no way the engine can pressurize the raw water intake without that filter in place.

 

[Julian]

I spoke with at Riva said there is no way the engine can pressurize the raw water intake without that filter in place.

I agree....there would be no way to build up any pressure! I would expect the boat to sound off as there would be a blast of water coming out of the side of the pump splashing all over the place...but at idle it would be under water and at higher RPM it is probably drowned out.

How quickly did the overheat occur? Were you gunning it?
Did you/it shut down quickly? If so...you should be fine.

 

[rkgdmd]

That is my other concern. About 5 minutes before the over heat, we were idling through a no wake zone. I lowered the music to talk to my wife and I know we were not overheating at this point. Once out of the zone I began cruising at 6200 RPM. About five minutes later I was only aware of the overheat because the engine cut power. Personally I think the alarm system on the boat is terrible. You don't visually see an overheat unless you are on the right page of the Connext screen.....which I wasn't.... and with the music on you can't hear the audible alarm. I've had overheats before and have always shut down the engines before the ECM cut power. Hope I didn't do any damage there. I'm mad at myself, but the alarm system really sucks.

 

[rkgdmd]

Ok...here's the update. Good and bad. I pulled the boat today and managed to remove what was left of the four bolts. They all were straight as an arrow so they don't look like they were side loaded by hitting something in reverse. The bad news is that while flushing with fresh water, the engine overheated. There was a ton of fresh water pouring from the orafice that is normally covered by the strainer so my hope is that with the new strainer in place the water will be routed correctly. No water from the pee hole either, but sometimes that happens when I have the bow way up on the davits.

 

[Julian]

Ok...here's the update. Good and bad. I pulled the boat today and managed to remove what was left of the four bolts. They all were straight as an arrow so they don't look like they were side loaded by hitting something in reverse. The bad news is that while flushing with fresh water, the engine overheated. There was a ton of fresh water pouring from the orafice that is normally covered by the strainer so my hope is that with the new strainer in place the water will be routed correctly. No water from the pee hole either, but sometimes that happens when I have the bow way up on the davits.View attachment 71385 View attachment 71386

I wouldn't have thought flushing on the hose with that off would have made that much difference, but it is easy to test.....just stick a cork in that hole and redo the test. And don't forget....engine on...water on....water off.....engine off.

 

[Beachbummer]

It is possible the water is not restricted even on back flow and flows straight through providing little to no cooling. Great news that the 4 bolts came off. Don't freak out until you put the cover back on. Best of Luck!

 

[swatski]

I wouldn't have thought flushing on the hose with that off would have made that much difference, but it is easy to test.....just stick a cork in that hole and redo the test. And don't forget....engine on...water on....water off.....engine off.

Yep. Either that or pinch the intake hose inside, that should help push the water coming through the flush port into the exhaust manifold/ cooling system.

I think that you may not have much to worry about, actually! (all things considered)

--

 

[bronze_10]

Looks like an over tighting issue... Maybe one or two have been broken for a while and adding pressure to the remaining bolt until pop!

 

[Matt Phillips]

that's a strange one. My guess is those bold heads and the strainer are now all part of Davey Jones' collection. As others have said, without any vacuum to pull water into the cooling system, my guess is that's what sounded the overheat alarm.

You might also try a small fibre optic camera that attaches to your phone like these:
https://www.amazon.com/s/?ie=UTF8&k...targid=kwd-392889051480&ref=pd_sl_5futogaw1_e

I don't know how well it'd work in the small confines of our cooling systems.

 

[Jimminh]

would be interesting to see what the other engine looks like, no doubt the same guy did both sides. and you could salvage the parts off the other side to test the this one, assuming the bolt heads don't just snap off....

 

[rkgdmd]

I wouldn't have thought flushing on the hose with that off would have made that much difference, but it is easy to test.....just stick a cork in that hole and redo the test. And don't forget....engine on...water on....water off.....engine off.

Wanted to try that Julian, but ran out of time.

 

[rkgdmd]

Yep. Either that or pinch the intake hose inside, that should help push the water coming through the flush port into the exhaust manifold/ cooling system.

I think that you may not have much to worry about, actually! (all things considered)

--

From your mouth to God's ears brother!

 

[rkgdmd]

It is possible the water is not restricted even on back flow and flows straight through providing little to no cooling. Great news that the 4 bolts came off. Don't freak out until you put the cover back on. Best of Luck!

Thanks @Beachbummer !

 

[rkgdmd]

would be interesting to see what the other engine looks like, no doubt the same guy did both sides. and you could salvage the parts off the other side to test the this one, assuming the bolt heads don't just snap off....

Thought of that but didn't have the guts or the time to mess with it.

 

[Papa]

In the picture, bolts 1,2,3, look like they were wrung off. Like over tightened just before breaking. Bolt 4 looks like the head just snapped off. Strange.
Papa

 

[gmtech16450yz]

Looks like corrosion to me. The final part that was holding is in the center of the bolts, as shown by the raised part. Put a wrench on the bolts on the other jet and see if they snap off, I have a feeling they will.

 

[rkgdmd]

In the picture, bolts 1,2,3, look like they were wrung off. Like over tightened just before breaking. Bolt 4 looks like the head just snapped off. Strange.
Papa

Your guess is as good as mine @Papa

 

[rkgdmd]

Looks like corrosion to me. The final part that was holding is in the center of the bolts, as shown by the raised part. Put a wrench on the bolts on the other jet and see if they snap off, I have a feeling they will.

The thought of this being corrosion opens up another whole bunch of questions. Are the bolts that crappy? Do I have some errant electrical issue? The zincs are pretty pitted, but most of them are still there. I actually ordered two sets of bolts/strainers/backing plates just in case the other side failed.

 

[Julian]

The thought of this being corrosion opens up another whole bunch of questions. Are the bolts that crappy? Do I have some errant electrical issue? The zincs are pretty pitted, but most of them are still there. I actually ordered two sets of bolts/strainers/backing plates just in case the other side failed.

Have you had a chance to test the engine with the hole plugged yet to see if the engine still alarms?

This thread resulted in no issue with the engine...was low water pressure:
https://jetboaters.net/threads/overheating-during-clean-out.4939/#post-84095

Another thought is if the thermostat is ok....this thread covers that possible scenario:
https://jetboaters.net/threads/possible-cooling-system-problems.13390/