I have a pro charger on mine also. I drained the water best i could from the block, pulled off the inlet hose and put a funnel on it. started it up and poured 6 gallons of r/v antifreeze thru it. I made sure pink was coming out the exhaust. The intercooler was the first to start spitting out pink. I shut it off and put the hose back on leaving the antefreeze in it. Hopefully the coolant ran thru EVERYTHING. This is all done in case they shut the heat off in the storage building.

Yes, that was our issue. We could get to a point where we were reasonably sure we had the proper mixture in the whole system, but it took a ton of time and material. As you probably know, somebody who knows what they're doing can drain one pretty quickly.

I have been winterizing for over 20 years without issue. I start the engine on the muffs, and bring it up to temperature. I have a bucket that has a through hull fitting I hook a hose to it with muffs. After the engine gets up to temp I hook up the bucket, start it up and pour RV antifreeze into the bucket. I pour 6 gallons through it. While I am doing that I spray storage seal into the carb and stop the engine with too much storage seal just prior to running out of anti freeze. I have not had a problem in 20 years and I live in Wisconsin where it goes to minus 20. It is in unheated storage. I put an XR with a - 2 Sportmaster on this year so I could not use the muffs. I had to do it by taking off all the hoses and drainiing everything. I bought a hose adapter for a low water pickup from CP but it apparently only fits an Imco as it won't work on the Sportmaster. If anyone knows where I can get an adapter that will work on the Sportmaster, please speak up.

merc has one

simply duct tape the low water pickup and use the muffs