Liquid Addiction

I need to pull both motors to replace my transom assemblies. They are 2004 496 HO's and they have approximately 475 hrs on them. Besides replacing spark plugs, belts and impellers is there any other Maintenance that should be performed now while the motors are out of the boat and accessible? Either internal or external?

Sydwayz

Is this Jeremy? What happened?

Go ahead and put new starters on them, and make sure they don't have any oil seepage out of the oil pan. Re-torque all of the oil pan bolts. (I had one fall out once, of course the hardest one to get to.) I'd also clean out all of the coolers since you have access to them. Also, make sure your air-drain actuators are in good working order. Do you have fresh water flush fittings on the boat already? If not, this would be a great time to install them. Do the spark plug wires too. We just replaced on on Tom's boat that was burned through due to improper placement. They are not too expensive on www.rockauto.com

Also, I'd replace your bilge pumps and floats while you are down there too.
Let me know if you need to borrow an alignment tool.

I recently installed new Crank Position Sensors on my 496HOs too. They are accessible from the top of the engine when in the boat, but they are a bear to get out. One of mine was bad, so I replaced them both.

Last, if you are unsure about how long the antifreeze has been in there, go ahead and R&R that too, albeit that doesn't require being out of the boat. Pick up some self-etching primer and Phantom Black paint and touch up any rust spots as well. Any of the marine shops there on Rte. 1 should have Phantom Black in stock.

I have a Rinda Scanner as well if you want to check the computer/RPM history. You should get 800-1000 hours out of a set of 496HOs if they have not had the crap run out of them.

BUP

Just adding to what Brian said.

I would check your flywheel / teeth closely - Also check the engine coupler for any form of wear. I would check the bolts of the couplers for proper torque. I had 2 - 496's in the past 8 years that one bolt back out and a couple of other 496's somewhat loose bolts. The 2 that had a bolt back out sounded like a bucket of bolts in a mixer being tossed around when the engine was running. Actually seen this on other engines as well plus some sheared off. .

I would change out your inline water check valves,

I would change out your t-stat especially if your anti freeze was never change out.

I would clean all back side engine grounds and make sure all connections are in good shape with no bare wires exposed.

I would check your oil coolers as well make sure its clean and clear of debris. U can also pressure test them as well for leaks.

Depending on your steering set up - it would be a good time to check all that out and all of bilge side steering components.

It would be a good time to check all your cooling hoses and the connections to them. The crimp type connections can leak over time.

Possible water circ pump change ???

Spark plugs - easy change when motor is out.

I would run a scan before you even pull the motor out. Run the scan with the engines running to see if anything pops up.

I would change out the water pressure sensor(S). they are prone to fail. And keep the old ones for a spare and or for testing purposes.

Liquid Addiction

Ya it's me Brian. Thanks for the advise guys. I have a pretty bad leak in the starboard side upper Swival shaft seal and just last weekend noticed the bilge coming on more frequent. So John and I opened the hatch and the port side had a slow leak too. Luckily I had already decided to do both transom assemblies so I wasn't caught off guard.