I have a 1997 Baja 29 Outlaw with 454 Mag MPI's. I have been having a problem with my port side motor. When I first launch the boat and start it, the port side motor takes about +/- 45 seconds for water to prime through the system and come out the exhaust. After the initial start it usually primes through fine and water comes out the exhaust immediately. This side also runs about 10 degrees hotter than the other side (about 175-180). The impeller and thermostat were replaced last year. Has anyone experienced this before? Could it be the sea pump itself or the water circulating pump going bad? Any advice would be great.

you runing in salt water ? could have internal clogging ? also seen the hoses come apart inside and cause issues, just saw one develop a leak from the pump to the cooler, Rob

i had same thing i replace the impeller and thermostac was no good . take hose off the intercooler blow water back in the other way to see if it clog ?if water come out clear your good there i took thermostac out put it in pot of hot water see temper it open atit was bad 180 it has to open at 140 now my boat runs 160 all the time

Thanks for the advice. I am going to change the impeller and thermostat again and see what happens. Any more thoughts?

It could be your sea pump housing if the impeller does not make a good seal it will take a little while toget it to pump water so when you do the impeller change the housing as well

THis may not be the source of your problem but check the connections on your intake hose. I spent 6 months chasing down a similar problem and found a broken clamp at the transom that was letting air in above idle. The clamp would appear to tighten but would not hold tension. I replaced the clamp and the problem went away immediately.

First check the pump and impeller - if OK, back flush the cooling system by removing the inlet hose at the T-stat housing and the outlet at the sea water pump- flush with a garden hose. I usually also pop it with some air pressure once filled with water just to make sure I get the most out. If this comes out clean and no old impellers and no other reason - you may want to remove the hose nipple at the very back of the engine where the inlet hose connects to the transom. The two bolts take a 7/16 wrench and a lot of patience ... if they are stuck, work them back and forth - but do not break them off - you'll be pullin the engine. Once removed you should be able to stick your "pinky" in the middle of the hose - if it's collapsed due to the build up of salt corrosion around the outside of the hose -take it to a qualified Merc tech and show them what you found. It's a sucky job and 80% of the time requires the engine be removed if the access just isn't there to change the transom hose. I've done 10 boats in the last 1 1/2 yrs all with the same issue....

Got two more to do in the next month that aren't totally collapsed - but we've checked and they are almost done. but with Destin coming up - we're baby'ing them to make that run then out they come.

First thing to do is change the impeller and housing--if its the plastic housing.

Thanks for all of your thoughts. Tomorrow I am going to replace the impeller and housing and test it out on Sunday. Hopefully that works. I appreciate all of the feedback on this issue.

Do you have sea strainers? How many hours on the motors?