Need some advice

[fstlayn]

I recently bought a '93 Advantage SR21 with the 7.4L/Bravo 1 setup. When I launch it, if I let it idle for few a minutes without getting on plane (like going through a lengthy no-wake zone) the temp. skyrockets to 200+. As soon as I get on plane it drops to 140-160 and stays there the rest of the day - even if I idle around. Could it be a bad impeller? I owned a jet boat before, so having a I/O is new to me.

[DMOORE]

I recently bought a '93 Advantage SR21 with the 7.4L/Bravo 1 setup. When I launch it, if I let it idle for few a minutes without getting on plane (like going through a lengthy no-wake zone) the temp. skyrockets to 200+. As soon as I get on plane it drops to 140-160 and stays there the rest of the day - even if I idle around. Could it be a bad impeller? I owned a jet boat before, so having a I/O is new to me.
The impeller should be changed out every year. Your motor should NEVER hit 200. If it were me, I would spend the $20 bucks on a new impeller, just to be sure. When changing it out, be sure it is complete,and not broken. If it is, you can backflush by pulling the main water hose that connects to the thermostat housing,( look in the housing to be sure there are no parts in there) and flush back through the oil cooler and the pump. Put the pump end of the hose in a bucket , to be sure you have all the parts.
Darrell.

[WopOnWater]

I would start with back flushing all the lines. It sounds like it has some junk stuck somewhere in the system. Pull the 2 hoses off the back of the impller houseing and backflush them with a garden hose. You also could have a thermostat sticking. To be on the safe side I would replace both the impeller and housing and the thermostat. At least you would have a starting point from there if it still runs hot after replacing those.

[fstlayn]

I really appreciate your feedback! Right after buying the boat, we took it to Elsinore for our first outing. After launching it I discovered that the water pump (?) housing was cracked and leaking profusely. So I bought a new housing & rebuild kit and replaced the housing, impeller, gaskets, etc. But from what I understand there is another impeller in the drive, right?

[watergun4u]

If You Have A Alpha One Drive There Would Be One In The Drive, But If You Have A Bravo It Is Mounted On The Motor I.e The One You Changed, I Would Check To Make Sure That You Dont Have Anything Stuck In The Pick Up On The Drive Unit, Sometime You Can Pick Up Sticks And Stuff That Gets Stuck In There, Also Check Your Cooler If You Have One One Your Motor, If There Is Stuff Stuck In There It Will Restrick Water Flow At Slow Speeds!!!!!!