new boat... hopfully minor issue

[jprice]

So I just purchased a 96 seadoo speedster jet boat. In great condition, and ran great during the test drive.

Took it out today for the first time as the proud new owner.(my first boat, btw)
Cruising around for about half an hour. Then the left engine starts revving higher than the right and I struggle to keep the rpm's the same. Eventually, this high pitched alarm goes off.
Believe it or not, I actually read a good chunk of the owners manual the night before, and remembered that this meant engine overheating.
So I follow the manual instructions to clear the impeller (assuming there was an obstruction), but I can't run it more than 30 seconds before the alarm kicks on again. Finally I find out that I can keep the engines at about 3000rpm without it overheating, and gimp back to the boat ramp at about 12mph.

Once I get it out of the water, I can see that the cable connection for the reversing gate for the left engine has broken, so the gate was basically stuck in the closed position. I'm hoping that this is what would cause the engine to overheat? I don't completely understand the cooling systems for these jet boats other than they need water flowing through them to cool.
Even though the left was stuck in reverse, I was still moving forward, so I'd assume there was still water going through the engine?

Ok, so after my long winded, noobie boater explanation, is the stuck reversing gate the cause of my overheating, or do I have a bigger issue on my hands?

 

[metriccrescentwrench]

Re: new boat... hopfully minor issue

Probably.

You'll find out after you fix it and take it back out.

 

[RWilson2526]

Re: new boat... hopfully minor issue

Probably.

You'll find out after you fix it and take it back out.

Couldnt be said any better.

 

[indy440]

Re: new boat... hopfully minor issue

If the reverse bucket was down it could have been causing that pump to cavitate, which could have caused a lack of water pressure to cool the engine. These boats don't actually have any water pump for the cooling system, they just take water (under pressure) from the jetpump and route it through the engine.

If it was like this for any amount of time I would question the impeller in that pump, The stock aluminum units wont hold up to a great deal of cavitation before becoming damaged. It shouldn't be too difficult to remove the nozzle and stator from that pump to get the impeller out.

It sounds like a good time to upgrade to two brand new ones along with new wear rings...

 

[jprice]

Re: new boat... hopfully minor issue

Thanks for the explanation indy.

I found that there's a clip that can be used to hold the reversing bucket in the open position. As a test, I'm planning on locking the left one open, and only using the right engine for docking/undocking.
Once I get into open water, I'll fire up the left one and see how it goes.
If it still overheats, I'll have to take it to a mechanic (crying all the way).

BTW, would any impeller damage be obvious to see by visual inspection (by someone who's never examined an impeller before), like being obviously bent, warped, or cracked? Or is it more subtle than that?

 

[indy440]

Re: new boat... hopfully minor issue

It'll have cavitation burns on it. It often looks like little holes in the aluminum. But thats only part of it, you will also need to check the clearance between the impeller and the wear ring. You can actually replace lost material on the wear ring with JB weld. But I think for it to be bad enough for it to be overheating there would be major, noticeable damage.

The pickup for the cooling system is normally built right into the wear ring. That could be plugged up too I suppose...

First things first, tie up that reverse bucket and try the thing. If it works then forget about it and have fun.

 

[BAproject]

Re: new boat... hopfully minor issue

I don't know that I would forget about it even if it works.

The odds are that engine will run hotter then the other....all the time.

Pull the pump and check it thoroughly.

 

[jprice]

Re: new boat... hopfully minor issue

Well, after the several weeks of rains, and flooding, and closed boat ramps, I was finally able to get it back in the water.

Unfortunately my plan didn't work. The overheating alarm went off after about 5-10 minutes.
I was able to take a peek behind when we first got going, and both engines had the "pee stream" going, so I felt good that the cooling system seemed to be working. Although they didn't seem all that strong, but I have no idea how far they're supposed to be spraying the water.

The really strange part is after I kill the engine, we float there for about 5 min to let the engines cool, and then I plug the key back in and the overheat alarm immediately starts again. So I take it off, assuming it's still too hot. Well half an hour later, and the overheat alarm still goes off when I plug the key back in. WTF??? How the hell can it still be too hot? I'm now wondering if this is some sort of electrical or thermostat issue? And why the hell weren't there any problems when we did the test drive damnit!

So now I need to find a decent boat repair shop. Given my past experiences with incompetent auto mechanics, I'm really not looking forward to this.

ugh... what the hell did I get myself into???

 

[WAVENBYE2]

Re: new boat... hopfully minor issue

What do your temp gauges read.??

 

[jprice]

Re: new boat... hopfully minor issue

There are no temp gauges. Just speedo, 2 rpm, gas, and an oil light.

 

[WAVENBYE2]

Re: new boat... hopfully minor issue

There are no temp gauges. Just speedo, 2 rpm, gas, and an oil light.

Really, Hmm??

 

[jprice]

Re: new boat... hopfully minor issue

Yes, really.
It's just a 14' jet boat. I guess they don't put all the bells and whistles on the smaller boats.

 

[Daley]

Re: new boat... hopfully minor issue

About mid-summer, I got my first boat and was completely clueless with regard to some of the problems I was having. I spent hours searching this forum and asking a few questions here and there. I consider myself to be pretty mechanically-inclined, and have even convinced some folks that there isn't anything I can't figure out. Still, I recall one time when I was at the lake with (yet another) wasted trip - the boat wouldn't run right, and I had that typical "fear of the unknown". I was asking myself that same question - what did I get myself into!?!?

Well, there are a few members here on iboats that have the patience and experience to help just about anyone out - ya just gotta ask the right questions. I learned that pretty quickly - they're certainly able to help, but they need good information to start with.

What I'm sayin is don't get frustrated, and by all means don't give up! Describe the symptoms as accurately as you have been, give detailed status updates and heed the advice given. Ultimately, what would have been $500 at the dealership turned out to be 79 cents for a vacuum line and a good carb-clean.

I love my boat now (a lot of that has to do with the fact that the family loves the boat now), and it doesn't cost squat to have a day's worth of fun on it.

iboats will keep you runnin, when you don't think you can do it yourself.

 

[jprice]

Re: new boat... hopfully minor issue

Thanks Daley.
I just got back from a local seadoo reseller, and got some good info from him.
I'm going to start with flushing both engines, then head back to the lake and give it a "high-tech" temp test. According to him, these older rotax engines are designed to run really cool. If there's any part of the engine, exhaust, etc. that is too hot to touch, then you've got a cooling problem, if not, then it's a thermostat or electrical problem.
I know it sounds kinda crazy, and obviously I'm not going to slap my hand down on a hot engine, but it's not hard to tell if something is too hot to touch.

 

[salty87]

Re: new boat... hopfully minor issue

If there's any part of the engine, exhaust, etc. that is too hot to touch, then you've got a cooling problem, if not, then it's a thermostat or electrical problem.
I know it sounds kinda crazy, and obviously I'm not going to slap my hand down on a hot engine, but it's not hard to tell if something is too hot to touch.

that's not the craziest advice. i was told the same thing about the exhaust risers on my 454 and it's true for the most part. some areas are hotter than others though.

you could also buy an infrared thermometer. i got one for the boat but i've used it all around the house too.

 

[Home Cookin']

Re: new boat... hopfully minor issue

battery powered meat thermometer works better than the meat on the tip of your finger

 

[jprice]

Re: new boat... hopfully minor issue

Just finished flushing both engines.

At the end of the 2-3 min flush on the right engine, the overheat alarm starts going off. I check, and neither the engine or exhaust are even remotely warm.
So I'm pretty happy thinking it's a thermostat issue. But since I'm doing it, I go ahead and flush the left anyway. No problems there.

Replace the thermostat, and flush the right again as a test.
Then I peek in the engine compartment and see this... (it's a little hard to see, but there's a small stream of water coming out of the block towards the exhaust)

...I think I'm going to be sick.

Is there any way to fix a hairline crack in the engine block other than buying a completely new engine?

 

[fixb52s]

Re: new boat... hopfully minor issue

Ouch! Before you think it is a cracked block, check to see if the head gaskets might have blown. If the cylinder is cracked, you can just replace that instead of the entire engine. Most times, it is more cost effective to get an entire rebuilt engine.

 

[jprice]

Re: new boat... hopfully minor issue

I don't know yet if there's a head gasket issue, but there's definitely a crack in the block.

I just finished attempting a JB-Weld patch. We'll see tomorrow if it actually works.


So should I get "Idiot boating noob here!" stamped on my forehead now?
I still don't understand how this thing ran so well during the test drive, but I feel like a complete moron right about now.

 

[WAVENBYE2]

Re: new boat... hopfully minor issue

Why are you feeling like a moron?? Things happen, believe me I know, you didn't go out there with a drill and drill a hole in your block, then ya I would say your a moron Any water in the oil??