Re: Simplicity Sunstar Hydro 20 basic hydro info
Well, at least in the case of the M20 engine, I can understand why someone might be concerned with the heat issue; they run VERY hot. I have 2 of these that I mow with. I also have a Sunstar with a CH20, but don't use it very often (just 'tilling and snow work) and have not noticed how hot it runs. Anyway, my drill is to "wash" the machines after mowing with compressed air. I think that helps with the heat issue by keeping the engine and cooling system (shroud around the hydro cooler and the engine fins) cleaner. Related to this, I found that using a multi-viscosity dino oil like 10W30 was resulting in oil break down. Consequently, very early on in my Sunstar experience I started using only HD30 oil in my M20 engines. Synthetic oils may not break down, but I still use HD30 in my M20's. I do use synthetic in my CH20, but heat has not been an issue with that machine.
Those decks are made of pretty good metal. As long as you have something to weld to, you should be OK. Even though it's a pain to R/R the decks, I try to clean under them when I know there is a big buildup of wet grass. Sitting with wet grass under there is what causes them to rust badly. I did lose one deck because of this back when I just did not have time to keep it cleaned out.
One thing to keep in mind regarding the deck bearings is that they are normally sealed. This means that using the zerks on the arbors (some don't even have zerks) will likely not put grease into the bearings. Before I figured this out, I was having bearings go bad within 2-3 years. Now, I disassemble the arbors and pack the bearings and they never go bad. Last time I checked, after 5 years the bearings still had plenty of grease.
One other wear item on the decks is the rollers. Not much you can do to preserve them. The drive shaft and gear unit are trouble free as long as they have lube.
The only weak point on the CH20 that I know about is the valve train. The push rods have been known to bend.