tournament ski magnum 350 impeller
 

Anyone changed the impeller on this? I am running 170 after a day of boarding at 5 mph when my buddy is running 120. I'm decent with a wrench on a car, oil changes, radiator swaps, brakes.

I don't know what option I have when looking up the part it had a bunch of alphas and bravos. It's a 97 ski brendella pro comp direct drive.

http://i44.tinypic.com/2mmcoix.jpg
http://i42.tinypic.com/314c6js.jpg


I read up on how to do it on other boats. But my water pump doesn't look like I can move it to loosen the belt. there is a pulley on top that looks like I can move it. Also how do i tighten it back up? Just push the pulley that moves until the belt is as tight as I can get it then tighten the bolt?
As for the impeller change I just take off the cover from the front of the pump pull the impeller, zip tie the new impeller to close the teeth and slide it in, replace the cover?

Water pump:
http://i42.tinypic.com/fuakuo.jpg

http://i40.tinypic.com/2nreae9.jpg

http://i39.tinypic.com/2h5k9vl.jpg



Pulley above the water pump I think I can loosen to loosen the belt:

http://i40.tinypic.com/wtelc2.jpg

Does your buddy have the exact same boat? 170 isn't that hot, certainly not overheating. 160 is normal for my boat.

That merc should have a 160 deg thermostat. Good idea to change those impellers once a year.

Loosen the belt, unbolt the water pump bracket from the block, disconnect hoses on back of pump, remove whole pump, do business and put it back in.

To tighten belt turn smaller bolt counter clockwise to tension, hold it in place and tighten bigger nut


Real easy

Todd:

I have same engine in my 96 Sanger and have done it many times. Very easy with basic hand tools.
I have the Mercruiser engine manual detailing part #'s West Marine will have parts in stock in the Sierra brand which are good if Mercruiser are not available.

Your pump may be either a two piece or three piece. Look carefully at the water pump housing to determine because you will may need an extra gasket which are crappy wax paper and very thin, so I always buy an extras anyways as they are under $5. If it is three piece(like mine) it is easy to have pump come apart in your hand when disassembling so watch carefully as the first time as there is a stainless metal diverter that can easily be reinstalled backwards or truned around. I reassembled mine backwards and overheated instantly upon first use the first time.

I suggest marking housing and hoses, bolts and pump body with different color sharpie pens prior to disassembly as it makes certain all pieces are reinstalled correctly then wipe off the marks with lacquer thinner or acetone. You are correct in that the tensioner releases the belt.

When you disassemble the pump pay attention to what direction the impellor rubber fins are folded. I suggest applying silicone, white grease or Never Seize in the housing before installing the new impellor which will only be there until water washes it away, but provides lubrication until water flow is established upon start up. Impellor is on a key way so it only goes on one way, but the rubber impellor fins need to be folded over to get it into housing. Whole job should take under 1 hour. I am in Sacramento and might be willing to help if you really need it or want a copy of my Mercruiser manual. Send me a PM via the board and I can get you my cell #.

Delta Force is correct about the 160" thermostat and mine always rides in the 160-170 range which is actually very cool.
The correct AC Spark plugs for that heat range are part # AC MR43T and Mercruiser recommends 5W-30 Motor oil which is also very thin for low heat range.
I can look up the thermostat part # in the evening at home if needed.

Rick

To loosen the belt you loosen that top pulley that's in my pictures with the gear looking bolt in the back? Also when you tighten it is there any way to get it too tight? Or just hand tight

Thanks for the help. I would think with a picture west marine should be able to figure out if I need a gasket. I'll head up there tomorrow.

Tension your belt as necessary... tighten the nut so the belt won't come loose at an inopportune time...

Well I went to west marine and they couldn't find the impeller on their computer so it looks like ill have to take it out this week and bring it in. Hopefully its good for one more day of boarding tomorrow.

Your boat isn't overheating...

^^what he said^^ that's normal running temp.

When you replace the impellor, get the Mercruiser upgrade kit, the old cover has a brass plate inside that the impellor rides against, and after awhile it grooves it out like a brake rotor. Which then causes cavitation in the pump, which then causes your engine to not cool properly. Get the upgrade kit and replace it, along with a new impellor. Hardley anyone I know, knows about this. It is a must do. Any top notch Merc mechanic will know about the upgrade kit. I paid 110.00 for mine. My engine runs right at 170 degrees (normal)