1994 Sea Doo SPI overheating.

[Carpetcolor]

New member her just bought a SPI and having trouble with overheating. Boat ran fine for about 20 minutes then got overheat alarm and steam coming out of one of the two pissers in back. I quickly idled to dock and shutoff. Back home I noticed there was a clear hose coming from under exhaust manifold then exiting rear right hand side of ski attached to a 90 degree elbow. In other words its venting just across from drain plug. It appeared to be at least partially packed with sand. Could this be cause of my overheat problem? I did pull compression with a tester I bought from Harbor Freight said 120 across both cylinders. Thanks in advance for help.

 

[LouDoo]

The clear hose you found is most likely the battery vent, if you have a sealed battery you won't use it.

You could try back flushing the engine, but I'm afraid you have a bigger problem. With 120psi compression your engine is done. Try checking the compression again, remove both spark plugs, ground the spark plug boots, check with a cold engine, and full throttle. See if the compression comes up you also might want to try a different compression gauge.

Lou

 

[Carpetcolor]

Thanks Lou I don't think it is a battery vent hose as it is not attached to sealed battery in any way. It seems to be attached to motor under exhaust manifold. I can't see exactly. It then goes to where exhaust manifold exhaust exits on starboard side. Just to right of pump if you are looking at back of ski. It us packed with what looks like beach sand mid way down line. I know the compression sounds low. I hope the guage I was using is pure junk. I guess the ski being a 94 low compression is par for course. It starts right up and ran great prior to the overheat alarm starting today. I wish I could post a picture on this site.

 

[Dennis]

The hose you are referring to is the cylinder drain hose. It is there so water in the engine can drain out after you shut it off. You need to clear the debris from this hose but it will NOT cause the engine to overheat. Your clog is probably in one of the other hoses.

 

[Carpetcolor]

Update: Purchased a better quality compression gauge from Auto Zone. This time I pulled both plugs before checking compression with a cold motor I had 150 lbs on the front and 155 on the back. The ski is a 94 could this be correct. I'm not the original owner but I don't think it was ever rebuilt. As far as my overheat issue I blew through all the lines with just my mouth and there seemed to be no resistance. The only thing I found amiss was there seemed to be a small shell stuck in the fitting that is attached to the hull/exhaust. I guess this would be the furthest downstream point of the cooling system. Now what I don't know is if this is the largest source for coolant water to exit boat. Does water go through the big exhaust pipe??? Hopefully I don't have some kind of bearing problem as I am happy with the new compression numbers. Thanks in advance.

 

[Sportster-2001-951C-Stock]

Anything can block water flow, shells, sand, gravel........ All lines need to flow without restrictions, sometimes sand can build up in the exhaust manifold cooling passages, the cylinder jackets, or both. Try connecting your flush hose to these points and flushing both ways, a "T" fitting with compressed air bursts injected into the water stream can help to loosen/dislodge sand sometimes. Jet ski engine can get amazingly plugged with sand if the operator persistently runs in shallow areas.

Be careful not to flood the engine with water though, water can back up in the exhaust system and flood back into the cylinders if you're not careful.

 

[Carpetcolor]

I have cleared out cooling lines as best I can. I ran ski in driveway attached to hose. Only had water flowing through starboard pisser. Does the port one only flow when ski is in water? This is the hose that comes out of 90 deg. Elbow on top of manifold? I have been told motor should never get so warm you cannot put bare hand on top of both cylinders? Thank in advice for the help.

 

[Sportster-2001-951C-Stock]

I have cleared out cooling lines as best I can. I ran ski in driveway attached to hose. Only had water flowing through starboard pisser. Does the port one only flow when ski is in water? This is the hose that comes out of 90 deg. Elbow on top of manifold? I have been told motor should never get so warm you cannot put bare hand on top of both cylinders? Thank in advice for the help.

Which one do you have?

Is it the 657, like this?:
http://fiche.seadoowarehouse.com/se...sp?Type=18&make=seadoopwc&a=284&b=13&Action=O
Or the 587, like this?:
http://fiche.seadoowarehouse.com/se...sp?Type=18&make=seadoopwc&a=284&b=12&Action=O

I don't think the engine should get so hot that you cannot keep your hand on it without being scalded. Uncomfortable, perhaps but not so hot it burns you. This is a general rule of thumb though, I don't remember how hot that motor actually feels, I sold mine many years ago.

 

[Carpetcolor]

It's the 587 motor. I'm not getting water flow through tube number 13 on parts diagram. All other tubes are flowing properly. Again this is just running on hose. Have not had chance to lake test. I'm afraid of blowing motor or not getting back to dock. My compression is just over 150 in each cylinder.

 

[Sportster-2001-951C-Stock]

It's the 587 motor. I'm not getting water flow through tube number 13 on parts diagram. All other tubes are flowing properly. Again this is just running on hose. Have not had chance to lake test. I'm afraid of blowing motor or not getting back to dock. My compression is just over 150 in each cylinder.

Where does the flush hose connect, is it fitting #24? If yes, is water coming from fitting #5 and fitting #9 also? If yes, that's good! Then try pinching hose that connects to fitting #9, then water might begin to exit from fitting #4.

If there are no obstructions in the cooling system and if pinching the hose at fitting #9 causes water to flow from #4, there may not be enough water pressure to completely fill the exhaust manifold pipe. It's also possible you may be losing too much water from fitting #8 as well, pinch that tubing also, and see if water begins to flow from #4

When water flows from fitting #4, you can be sure the exhaust manifold is full of cooling water, as it should be.

Anyway, you should try to obtain a copy of the owners/operators manual if possible, it will tell you how to use the flush hose properly (which hoses must be pinched, if any).