Per TimBle (http://www.rcuniverse.com/forum/m_11..._2/key_/tm.htm) he's got some good insights. He should know, as he helped me write a castor/synthetic comparison article. How's it going TimBle!?

"I suspect that there are other reasons for the corrosion many see in their engines.

1) rust is already present in the metal used for the steel components of the engine. Poorly processed steels and veryhigh carbon steels are prone to surface corrosion no matter what we do to them. Lets face it, hobby engines are low volume so the steel used is going to in proportion to the final cost of the engine...

2) Poor quality methanol is being used

3) dirt /contaminant ingestion via the engines carb would be trapped in the crankcase and if there are salts i.e. flying in an area close to the ocean or salt pan or salt lake,

4) Copper ions from poor quality brass fuel tubing, brass clunks etc. I tend to use aluminium and steel components in my fuel systems."

New bearings is a must. +1

On an engine with that rust, I would first clean things with Dawn Power Dissolver. That makes sure the red is really rust, not baked on oil. It also gets all the baked on oil off. It is not an over night treatment. It will eventually start to discolor the aluminum. For the rust cleanup, I like CLR. If the part is left in it to long, it takes a black oxide finish. Most of that can be cleaned off with s scotch bright pad.

The only issue with assembling a Saito is the cam timing is easy to get wrong as it is somewhat difficult to hold the timing while you are putting the cam housing back on the engine. I use a this piece of flat shipping container clear plastic. Even the stuff the use to hold the collars nice in new shirts. Take you digital calipers (every one has a set or two don't they?) and close them on the cam gear teeth. You want them to engage the gear at the bottom surface of the cam housing. Lock the calipers there. Then lay them on the piece of flat plastic and scribe two lined to the inside of the caliper. Use and Xacto knife and cut a segment out of the plastic along these lines. This is your timing tool. It works for all Saito cams. You set the dot to the bottom, and slip the U shape you just cut onto the cam. Make sure the gasket is between the U and the timing tool. Set the engine at TDC and drop the cam housing in place. Slip the U timing tool out from under the housing and your timing is set. Some of the Saito allow you to lift the cam follower out the top. In that case, you can simply use the push rod as a timing tool Remove the intake lifter. and drop the push rod in the hole. There is an oil hole on the cam and when the push rod engages the hole, it is in time for TDC. You can't get it off a tooth even though it is a loose lock. Either of these methods will work whith the engines that you can remover the lifters out the top.

A bit of white lithium grease on the cam and lifters, as well as the rocker pivots and push rod ends is a good idea. There isn't much oil that migrates up through the cam to the top end, so the cam, lifters and rockers are somewhat oil deprived.

Last, I've never been a fan of Cool Power. Ido like the Morgan Omega though.
Don

This is what concerned me most. Not that there wasn't oil in the rockers but, that there was a lot of it when I removed the rocker covers. My intentions are to check all the gaskets (have replacements) and double check the crank case to ensure nothings messed up. Granted, I'd rather have oil in there then not but, the amount of oil seemed excessive. The investigation continues…

I'll have to inspect the ring this evening when I do a little disassembly. I picked up a rear bearing today (no front bearings in stock) so hopefully I'll be able to tear down and build up again tonight. When I've torn down other 4 strokes and typically the front bearing was found in pretty good shape so, here's hoping. Deets to come.

I popped open the engine and after some mild finger scrubbing with water and Bar Keepers Friend, I removed a light residue from normal engine wear and tear. Once I washed the parts thoroughly and gave them a hefty after run oil rub-down, the piston and ring looked really good. Excellent! However, as I'm peering into the exhaust shaft, the valve is pretty coated in gunk. Looks like I'll be doing some cleaning...

Its starting to come back to me how much fun this is. The crankshaft is concerning me because I'm having a hard time getting it out. Pulled out the butane torch, heated up the crankcase, attempted and got no movement. I'm worried it'll end up like my O.S. .91 where I couldn't get the bearing out at all and ended up purchasing a new crankcase. Kinda' frustrating...

The 'damage' appears to be more varnish related like you said. But the crankshaft is pretty corroded (for my taste). I've got a Dremel and some soft tips so I'm going to polish off the parts with Bar Keepers Friend.Its been working fantastic thus far for removing all gunk.

I like the tool set for the bearings and I think that's going to be the route I'll take. While it is somewhat expensive, it's a lot cheaper then damaging the engine trying to remove them without the proper tools.

LOL! Yes, that is exactly what I did with one of my engines. Had to use welding gloves to hang on to the crankcase. After talking to a friend who's an engineer for Delta, he said they would throw items into an oven to heat it up, then dump liquid nitrogen on the bearing and hammer it out.

What are the tools of the trade for dismantling an rc airplane engine? For those who enjoy it or are just starting to get into it - a list of tools that others have used that work (and are reasonably affordable) would be a great resource. I'm talking from a wood block (size and thickness?) to more sophisticated items like a bearing removal kit would be really nice to have on hand.

Diameter's "to fit" for hammering out bearings. Wood for the fact that they won't damage your parts (e.g., crankcase)

For heating up engine casings to expand them for easier bearing removal.

For obvious reasons. If you're gonna torch something, you'd better have a way to put it out if it gets out of hand!

For handling super hot items (e.g., bearings and casings)

I don't ever use a hard surface to pound on my engines. And when I do (e.g., concrete floor) I pad it with a towel or thick newspaper to avoid direct contact.