On the water Help User Group - Join to Help or post @HELP when you are in urgent need

[carl raisor]

Its just really hard to find info that is "scarab" specific on the web.

 

[Murf'n'surf]

Bring a flashlight and long nose plyers. Look up from under the boat into the intakes. Hopefully you'll see the debris right there. Pulling it out fixes it!

 

[Murf'n'surf]

Its just really hard to find info that is "scarab" specific on the web.

We will walk you through it. You should probably start a new thread in general discussion to get more attention and help future owners find your solution.

 

[carl raisor]

ok will do guys. I cant tell ya enough how much I appreciate all the advice. Thanks to all

 

[robert843]

@carl raisor glad you got back to the ramp! For future reference some may disagree but if you see debris in the water unless its something large like a log that may damage the hull don't slow down stay on plane you have a much more likely shot of clearing it if your are moving at planing speeds. Hope its an easy pull out tomorrow and as mentioned earlier learn the reverse move it does work for most easy clears.

 

[itsdgm]

@carl raisor welcome aboard and sorry to hear about your issue. Most of us are YAMAHA boat owners so we have a better idea of how Yamaha cooling systems work.

DISCLAIMER: I'm not very knowledgable about the "closed loop" cooling system on your boat.

From what I remember, the rotax engines are closed loop and the exhaust is open. So it's quite possible that your engine temps would read fine while your exhaust system could be overheating if the water intake for that is blocked. So, it would be a good idea to verify with the scarab guys or a dealer just exactly how your system works.

Either way, it sounds like you took all the precautions to prevent major damage. So I would think you're ok there. But do a bit more research to see how your engine cooling and exhaust cooling systems work.

 

[Murf'n'surf]

Seawater runs through a heat exchanger that carries the coolant. The engine will over heat when raw water flow is reduced.

 

[ScarabMike]

Ok sorry I have been travelling, and just saw this.

@carl raisor the smoke your seeing is normal on the Rotax powerplant. Its a mix of exhaust, and water coming off of the engine, and transferring out of the heat exchanger. Sometimes it can get heavy, but nothing to worry about unless your engine temps get high on the dash.

There are two-three ways to monitor your engines temp.

One is the dash. On my Seadoo and Scarab, the average running temp is about 180-190 degrees. The ACE engine is slightly cooler. Anything within 10% of that mark should be fine.
The second is your coolant overflow bottle. This is just like your car. If the coolant is missing, bubbling, or overflowing, stop the boat.
The third is oil pressure. All of these systems have sensors that will trigger a check engine light on the dash. A couple might even shut down your engine, or place it in limp mode.

Its important to know that even though the shaft is protected, the debris will clog the water inlet, and the even though the engine itself will not be damaged by this, the exhaust can be damaged severely, and can melt. This may block your exhaust, and keep your engine from producing normal power.

Also, these engines have wear rings. They are plastic, and are meant to fail. If you get sand, rocks or any hard debris in the pump area, it can score up the wear ring, and cause cavitation. But, its an easy fix, and they have stainless steel rings available as replacement.

I hope this helps.

 

[carl raisor]

ok I am looking into it asap this am. are these scarab boats prone to issues?

 

[ScarabMike]

@carl raisor No not the engine packages. Only issues we have seen with the Scarabs have been quality control for the most part, and dealership knowledge issues. These have progressively gotten better as they get used to working with the power plants.

 

[carl raisor]

I looked up inside there. I can see the impeller but it doesn't look like anything is in there. Not sure what else it could be. Does the jet drive have a warranty?

 

[Bill D]

It is very possible that whatever debris was in there fell out when you pulled the boat out of the water. Also, it only takes a small piece to cause major cavitation and make your boat sound like it's going to come apart.

 

[Julian]

What you ran into is the one thing jets boats don't do well with .....debris in the water. You almost certainly just sucked up a small twig. The reverse move, where you stop the boat, put it into reverse to get the boat moving backwards, and then kill the engines and put the boat drives in the forward position flushes out 95% of stuff that I've ever sucked up. Learn this move! It will become your friend.

So look very carefully now at the pumps before putting her back in the water. A one inch piece of hardwood stuck in between the blade and the wear ring will cause what you describe. But as others have said....it might just have been a stick that fell out.

 

[txav8r]

@Carl raiser , debris is hard with a jet boat. Your best bet is to avoid it completely. When that isn't possible, your other option is to prevent as much as you can from being sucked up, especially since you don't have cleanout ports like the Yamahas do. I don't know what the intended method to remove the debris is with a Scarab but I am sure they have thought of that and have a recommended procedure. Swimming under the boat to remove it is DANGEROUS because you can get your arm trapped and drown. Limping home may be hard to do too.

@Julian is right about the "reverse move" but I don't think your throttles/gates/shift is set up the same as our boats either, so I don't know if it will work. I do know your reverse gate is very different than the Yamaha. But the idea is to get the boat moving in reverse (when you are out of the debris field), then to kill the engines quickly, with the lanyard (if you have one), and open the reverse gate, so maximum water flowing backwards through the pump due to backward movement, can wash out the pump and intake area from offending debris.

When you can't totally avoid a debris area, it may be best to stay on plane at higher speed to skim over the water, giving less chance of the debris to enter the intakes. Debris comes in many shapes and sizes. Grass and weeds can be bad and trying to go at high speed over grass may or may not work. If it is growing and just touches the surface, higher speed may work. If it is floating, your going to suck it in. The boat hull will push much of any floating debris to the side as it passes, but grasses can still get ingested. Again, best way to not have to deal with this is to avoid these areas completely. And watch the water in front of you at all times. In the yamaha, a tiny piece of driftwood can cause almost total loss of power, and an overheat pretty quick if you try to continue without clearing it. Your cooling system may give you more leeway but again, hoping a scarab guy will answer you directly @ScarabMike @Scarabsteve @Scarabguy16

 

[davel501]

I looked up inside there. I can see the impeller but it doesn't look like anything is in there. Not sure what else it could be. Does the jet drive have a warranty?

Just run a feeler gauge around the impeller to make sure there is nothing stuck between the impeller and the wall. Happens to me from time to time. The smoke is just your engine working harder at a lower speed than you are used to leading to more exhaust. If you don't find anything there then it probably shrunk as it dried and fell out. The only way to hurt your boat is to run around with something in there, letting it thump, instead of stopping and clearing it.

You most likely did not do anything that will have any lasting effect your boat.

 

[md11pilot]

Thanks for putting this group together. Hope I never need it but glad it's there. Hope I can help too. I'm still a nubie to jet boating.

 

[carl raisor]

to all. I did find a stick about .5" in diameter lodged in the impeller. I removed and took boat out yesterday. It ran great! thank you guys. I did the reverse move a few times to get a hang of it. My wife thought I was nuts but I think it makes the most sense. Problem though... my hands wont fit in the great to remove whats there if in fact it happens again. Is there a tool made for that? anyone made one their self ?

 

[Julian]

So people have fashioned "sticks" for poking into the clean outs on Yamahas to push stuff off the intake grates, so I'll bet someone has come up with something. But often its hard to get those little hard wood twigs out-which is why cleanout ports are handy. The good part is this sort of wedge doesn't happen often, and when I see debris I do speed up if it looks small. I think the pump going at speed can chop and spit out stuff much more effectively if it has the HP behind it.

 

[smthng]

Go to harbor freight and get the longest pair of slightly curved forceps they have. They look kind of like medical pliers and usually have a little locking clip or something on them. I keep two of these on the boat at all times for cleaning out the pumps and reaching things that fall into crevices around the boat in general. Priceless.

 

[itsdgm]

That's great @carl raisor. Glad that you're back up and running.