I have a couple of 36 year old OS Max 35S engines that I want to put to use soon.  I am going to use a crock pot with anti-freeze and cook these puppies until they bark.

Questions: 

Do they need to be taken completely apart to be cleaned? 

What do you think of after run oil?  Is it widely used or is there another type of oil that is readily available?

Finally, I need a prop drive washer, outer washer and nut.  Who carries spare parts for the OS 35S?

As always, thank you for any and all suggestions.

Hi dick,

The crock pot should get most of the junk out. I usually pull the head and back plate for this, but I'm told you don't have to. I have an ST60 that has a frozen wrist pin. I crock potted it for a very long time and the pin is still frozen. Right now it's soaking in Penetron. Hopefully that will free it.

I use Marvel Air Tool oil or Magic Mystery Oil for an after run oil. Good idea to put this in if the engine is going to be setting for a long period. I don't use it for engines that are used regularly.

I don't know on the parts, but I'd post your need in the classifieds here.

Heat and penetrating oil will do wonders.  If you've got a part that's frozen because of a bit of corrosion no amount of crock-potting is going to help, but expanding the outer part may free it up, and expansion/contraction cycles will often break the corrosion (which is usually quite brittle) allowing you to disassemble.  The nice thing about this is that if it's a part that's frozen because of old polymerized castor oil, heat will also soften the castor.

There are some web sites out there detailing rebuild efforts on antique gas (as in street gas, not gasoline) engines that have sat in sheds for decades -- if you want information on freeing up old stuck parts, there's a wealth of knowledge there!

Most model engines will just have well polymerized castor oil, though, which is a much easier nut to crack than rust and other corrosion.

Brian,

That's were I'm at. The engine needs a new ring but the wrist pin isn't coming out yet. I will get it out eventually.

Dick,

I would just try crock potting them and see what you have. If something is stuck, then go to penetrating oil and perhaps a touch of heat. They will usually come free with that.

I know most people use the crock pot/antifreeze method, but I still stand by my boiling water and *dishwasher* (not dish washing) soap.  It takes only minutes, not hours.  removes everything (doesn't harm plastics as far as I have seen) including head paint, frees up all parts.  The parts look like new once finished.  a tooth brush will remove anything between fins and such.  I boil for about 30 min.  Never had any discoloration either.  I believe that is a water problem not the *dish washer soap*.   Never tried "dish washing" soap, the two are different!  I have young Grandkids around at times, along with my puppies.  The antifreeze method is NOT a consideration around here.

I use about a 50-50 mixture of Air Tool oil and Rislone for assembly and after run/storage.  The Air Tool oil is what is sold in little bottles as After Run Oil and costs WAY less.

Big Bear