dbird wrote:
Dan, thats a good idea, will try that on Monday. It has also crossed my mind that winterizing via pink stuff through the muffs may be the culprit. I'm wondering if that gravity fed hose from the tank can provide adequate flow. Either way, for several reasons I wont be using the tank to winterize again.
I have posted on this point many times
DO NOT use that method, its risky and is really appropriate only for engines with closed cooling. Yes I know some have done it and never had a problem. Well if you read OMC's OE manual, they do not tell you to do that. They tell you to drain and leave it dry, or drain and back fill with AF. I think Merc says the same thing. Volvo does say you can use this method if you remove the thermostat, but I personally think their manuals stink, poorly translated and very vague.
I have replaced an impeller on my Cobra pretty much every season. I always run it on the muffs for tune up, etc and have NEVER had an impeller burn with good muffs and good water pressure. And, this is a salt boat, with some barnacle growth in the water intakes that has to be broken up each spring.
The only time I have heard of issues with Cobra impellers and housings burning, is when you use an aftermaket housing with an OE impeller, or vise versa, they do not fit the same. Use the whole kit from one manufacturer, OMC, or Sierra, do not mix parts.
Keep in mind, that an AF/water mix, is more dense than just water. That is specific gravity and that's what you measure when you check antifreeze protection. As such, it is harder for the impeller to suck this up than plain water and it's not under the kind of pressure that a hose provides. This is even worse on Volvos and Merc Bravos, the impeller is way up on the engine, the AF/water mix has to travel several feet to get to the impeller. On a Cobra or Alpha, the impeller is in the drive so it's not as bad, but still I say when winterizing, do it right and drain and back fill or leave dry....