What a time to be changing my impeller… 6 years ago I changed out my impeller and I’m pretty sure I just took the bolts off the back of the sea pump housing and the two hose clamps in order to put the new one in. Is that the easiest way of doing it or removing the pulley. I’ve watched a bunch of videos of impellers being taken out, a few threads with walk through but their setups didn’t look similar enough to mine. Where would I take the tension off the belt? I’ve read thread saying about the water pump but I don’t see where. That pulley on the water pump has 4 bolts. What’s the average price a shop would charge too?

There should be no reason to remove the pulley from the pump in order to change the impeller, assuming everything is stock Bravo parts.

For parts breakdown/look up click here:
https://www.mercruiserparts.com/bam/...93536/28146402

I recently replaced the impellers on both of my 1990 454 mag/bravo engines. Don't think it's even possible to replace the impellers on my boat in the bilge but it's a twin and very tight. If you have a single, most of the following still applies but will be easier to get at.

Removing the pumps isn't too difficult, then you can work at the bench. No need to remove pulley from shaft to replace impeller.

On mine, there's two 5/8" head bolts just behind the large water pump hose at recirc water pump. Need to remove bottom bolt. Top one only needs to be loosened and pump can be lifted off the top bolt. Much easier to get at top bolt if the large hose is removed from recirc pump, but can be done with it in place.

There's a long bracket that loops under the harmonic damper and attaches on the other side of the eng (item# 34 on SB's pic). This long bracket is used to adjust belt tension and has a long slot cut down the middle. On mine, I need to remove a clamp (to eng block) securing the water hose from oil cooler to thermostat housing so I can push that hose out of the way to get at the bolt for raw water pump long bracket. No need to take this bolt all the way out. On mine, that bolt also holds the alternator mounting bracket.

Where the raw water pump bracket attaches to the long bracket prev mentioned, there's a 1/2" nut/bolt then needs to be removed. I do this purely by feel.

Here's a trick that helped me considerably. The water hose that connects raw water pump to nipple on the transom is very stiff and just long enough to reach but not long enough to move raw water pump fwd enough to get at the clamps on back. I learned to disconnect that hose at the transom nipple, use some bailing wire or similar clamped to the hose using the old hose clamps and let hose fall under the eng. This will allow the raw water pump to be moved fwd enough to get at the clamps on the back side. When re-installing the pump, secure hoses to raw water pump then as you start moving the pump back into place, pull on the bailing wire to snake hose back into position at the transom nipple. First time I did this, I didn't use the bailing wire and had great fun getting that hose routed properly back up the transom nipple.

Oh yeah, make sure to identify which hose goes where on the back of the raw water pump, other wise you may have to remove pump again to switch them back.