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burgettw
06-29-2009, 07:07 AM
So I went out yesterday and got one problem fixed now the boat was getting real hot like 220 in a hurry to...what temp is normal for these boats suppost to run and how do you back flush the motor to see if there is a blockage or anything and btw is a chevy 350 engine with cobra outdrive. thanks

MOP
06-29-2009, 10:59 AM
Is good flow coming out of the exhaust? Is one side hotter then the other? A couple of ideas below!

First pull the feed hose of that goes to the block from the drive pump put it in a bucket and start the engine 30 seconds the bucket should be pretty full, if no water go on to the next paragraph!

Real hot fast is usually the sea pump, the Cobra pump is simple as you ,may know. It is important to back flush, not only the P/S cooler but back through the shield from the inside, many times shards of rubber will get caught in the hose just before the shield. Do not be tempted to remove the big screw plug on the port side of the upper gear case, the one that is or was under the plastic Cobra emblem yes it is the water passage but a nightmare to put back as the blind backer falls off in hte water passage pulling it serves no purpose!!!!!!

burgettw
06-29-2009, 11:24 AM
Is good flow coming out of the exhaust? Is one side hotter then the other? A couple of ideas below!

First pull the feed hose of that goes to the block from the drive pump put it in a bucket and start the engine 30 seconds the bucket should be pretty full, if no water go on to the next paragraph!

Real hot fast is usually the sea pump, the Cobra pump is simple as you ,may know. It is important to back flush, not only the P/S cooler but back through the shield from the inside, many times shards of rubber will get caught in the hose just before the shield. Do not be tempted to remove the big screw plug on the port side of the upper gear case, the one that is or was under the plastic Cobra emblem yes it is the water passage but a nightmare to put back as the blind backer falls off in hte water passage pulling it serves no purpose!!!!!!

Yes sir good flow seems to be coming out just like before it seems to be the same amount as before and ill try the bucket thing this afternoon but yea the big screw someone had taken it off before so I welded it up but ill try to figure something out I just figured you guys would have ran into this problem before and knew a simple fix...but what is the normal temp they usually run

MOP
06-29-2009, 08:23 PM
If you feel you have the same flow out of the exhaust the next thing to check is the Tstat, that is the only thing that can make it get hot with good flow.

Phil

burgettw
06-30-2009, 06:46 AM
If you feel you have the same flow out of the exhaust the next thing to check is the Tstat, that is the only thing that can make it get hot with good flow.

Phil

I checked it on the stove with a tester and it opened up at 140 and I even ran the motor without it and it still ran 190

MOP
06-30-2009, 03:37 PM
Ok you need a buddy for this one! Get a piece of clear plastic hose to insert between the block outlet and the exhaust, take it for a ride and watch for air bubbles in the hose. That points mainly to a head gasket but can also be air being sucked in before or around the housing. Yes a head gasket can allow air into the water jacket and show nearly no signs of it being bad. If you are positive of the pumps integrity then start pressurizing cylinders, with the block full but the Tstat housing removed so you can see the tiny bubbles! You can even tell which side is leaking! But I would do both as a matter of course!

burgettw
07-01-2009, 06:58 AM
Ok you need a buddy for this one! Get a piece of clear plastic hose to insert between the block outlet and the exhaust, take it for a ride and watch for air bubbles in the hose. That points mainly to a head gasket but can also be air being sucked in before or around the housing. Yes a head gasket can allow air into the water jacket and show nearly no signs of it being bad. If you are positive of the pumps integrity then start pressurizing cylinders, with the block full but the Tstat housing removed so you can see the tiny bubbles! You can even tell which side is leaking! But I would do both as a matter of course!


K. Ill give that a whirl thanks man!