Mickey mouse ears - how much water

[adixon]

Novice question. - Recently bought an '87 Galaxy with a Merc 470 which wouldn't start. After 4 weeks of troubleshooting and overlooking clues - points closing at 12 deg BTDC - plug wires - fuel blowing out of the carb. Finally realized that the new starter the PO put in was CCW. Changed the starter and she fired first time. Anyway, now she's running and not trusting the PO, How much water should be coming out of the exhaust at idle when it's hooked up to a hose? Just want to know if I need to rebuild the pump.

 

[MrBill]

Re: Mickey mouse ears - how much water

My recollection is that the "470" ran through 1984, and then the similar 224CI engine was referred to as the 170 I/L4 in 1987. None the less they are very similar, closed cooling system, water cooled voltage regulator, stator charging system etc., and yours should have the larger 4" heat exchanger for cooling.<br /><br />Check out www.mercrusierparts.com for schematics on your entire engine, including part numbers.<br /><br />Unfortunately, with the muffs providing pressurized water through the cooling system you'll won't be able to proper check if adequate cooling water is being supplied. If it runs cool enough on the hose, but overheats when in the water, chances are real good the impeller needs replacement in the lower unit. Not a big job...$150 at a reputable repair shop if you're not comfortable doing it yourself. I replace mine every other season to be on the safe side.<br /><br />You can't tell from the amount of exit water if it's working properly. If necessary, get a large bucket or drum to provide water for the intake and run the engine to see if the outdrive takes in adequate cooling water to maintain a cool running engine. It should be able to cool best at idle, if it gets hot while idling, you don't have enough flow. As ALWAYS, never test out of the water with the prop on...take it off, even if you intend to keep it in neutral. TRUST ME on this one. Good luck.

 

[adixon]

Re: Mickey mouse ears - how much water

Thanks MrBill. I only saw a small amount of water coming from the exhaust and was a little worried. Didn't run it long enough to get up to temp. It does have the 4 inch exchanger. the engine is a Jasper rebuild with about an hour on it - then it sat for a year or more. It is sweet though - you could put a glass of water on it and not see ripples. The valve cover has 470 on it but the PO said it was an MCM 170 but then he said it was a CCW engine too. Once I get some new tires on the trailer I'll get it in some water.

 

[Northern Eclipse]

Re: Mickey mouse ears - how much water

adixon Go ahead and do yourself a favour and change the impeller Its a new motor you don't need to fry it....why was the motor replaced to start with ..it didn't overheat did it???

 

[adixon]

Re: Mickey mouse ears - how much water

PO was a little cagey as to why the motor was replaced but the stern drive was replaced too. I've talked to the shop that replaced everthing and I'm comfortable with them - in fact, if I'd talked to them first I'd probably have been in the water already. Just to see, I'm going to stop at the Tractor Supply Co on the way home tonight and pick up a big mud bucket to stick water and the drive in. Probably stop by the boat store and pick up the water pump kit. Won't hurt to have one on hand.

 

[Northern Eclipse]

Re: Mickey mouse ears - how much water

Has this boat been run in fresh water of salt, the reason I ask is because I re-read your post and it dawned on me that you only mentioned the motor was replaced , and now outdrive also.. but what about the exhaust manifold/riser, it could be plugged and therefore will cause overheat and restricted water flow....

 

[beckerdg]

Re: Mickey mouse ears - how much water

You want to be pretty certain your pumping water before taking this boat out and letting it overheat. The 470 engines do not handle overheats very well. Very easy to lose a voltage regulator or a head gasket on this engine when overheated.