I thought I had the perfect way to winterize my 500 EFI's. I use the bottom half of a 275 gal.tote. On the first engine I start by dumping 12 gal. of -100 degree anti freeze ( 6gal from last year and 6 gal new ) in the tote. I hook a pump up to a muff and circulate the antifreeze thru the running engine until the temp gets to over 150 and I'm sure that the thermostat has opened. I then fog with MM oil and shut it down. I then un-hook and move the tote and pump to the second engine, add 6 more gal. of new antifreeze and start the process over again.
Now here is my problem : I can get the second engine up to 150 fairly quickly since the antifreeze is still hot. For the second year the 2nd engine will start to miss and die before I can get it fogged. It will not restart. The only think I can think is happening is the hot antifreeze is effecting the fuel delivery like a Vapor Lock or it is effecting the cool fuel system some way. I would bet once it cools down every thing will be fine.
Does any body else have any other thoughts ?

Interesting. Yeh, your probably turning the Cool Fuel heat exhanger into a Hot Vapor Maker.

On a side note: what kind of pump are you feeding the antifreeze to the muffs with ?

That's crazy. Just drain the blocks and lines. Fill up with antifreeze or just leave it dry.

+1
I drain the water (closed cooling) from headers and cool fuel, power steering, reinstall plugs and with muffs in place while hooked to elevated bucket full of pink stuff. Run 4 gallons thru, shut off and drain again to ensure room for expansion just in case

When you drain the block will water left in your circulating pump still drain?

Yank the hose off of it and drain it.

Thanks I wasn't thinking looks like my weekend project.

I pull the large hose off the bottom of the pump just to check.

SB, It one of those 120 V pumps for draining Pool covers, you can hook a garden hose to the top
I forgot to say that I drained the blocks first

A Shop Vac is your friend.