Well I've read alot on this particular subject, for the reason that I've wanted my engines to last as long as possible.
First, for the wearable items. On average a piston and sleeve on most modern ABC (Aluminum, Brass, Chrome) builds will last anywhere from 2 to 10 gallons depending on the care taken with the motor. Every little variable plays a part in how long an engine will last. And remember, these engines are small, and don't get me wrong here, they may be strong, yet they can be VERY delicate.
Now for the clutch, a clutch wears out because it's what keeps your motor from blowing up. It's ALWAYS spinning inside the clutch bell. And when you have two things creating friction on one another, the softer material is going to wear out, no matter what you do. 6 months / 3 gallons for a clutch is pretty good. Usually a clutch will burn out in a gallon. Well not totally burn out, but be worn past the point of it's best potential.
Now, with a 2 stroke engine, you don't have oil in the "crankcase" so you're depending on the fuel/oil to do all the work of lubricating the sleeve and piston, all the bearings, and the bushing on the connecting rod, and everything else. Now, since oil burns you'll never get a perfect oiling job. The richer, the longer the oil will last when running. So more engine life will prevail.
Maintenence is also a VERY important part it the maintence for your engine. The engines maintence will prove more than helpful when looking into the engines longetivity. Doing such things as adding after-run oil after running. Changing glow plugs, keeping the air and fuel filters clean, all play an important role in an engines life expectancy. Basically, if you neglect your engine by not keeping an eye on these things, you will more than likely decrease it's lifespan. So, take care of your engine, and make sure it's always cleaned up and ready to go before and after your running time.
The importance of after-run oil. During the engines runtime and offtime you'll have major temperature changes, which causes moisture to build inside the crankcase. After-run oil is designed to eliminate moisture inside and out of the internals of your engine. Adding after-run oil also lubricates the piston, sleeve, crank and connecting rod, and all the bearings. This is more than needed, since moisture leads to rust, which will lead to failing parts.
And last, but definetly not least. Tuning of your engine is probably the most important variable when it comes to getting the most out of your engine. Whether you run it for all out performance, or for the longetivity. The richer you run your engine, the longer it will last, but don't get me wrong, no engine will last forever. The leaner you run your engine, the more performance you'll get, but it will shorten the life. Tuning is also predominate of fuel types. Yes, no matter who tells you, there is a difference when running 10% nitro or 20% nitro. The more the nitro percentage, the more power your engine will produce, but the higher percentages will also cause the oil to burn off quicker, causing less lubrication. Therefore causing things to wear out quickly. So that's the tuning issue.
Now, let's wrap this up and see what all we said about the engine. First, we looked into maintenance, such as using after-run oil, cleaning the filters, making sure the glow plugs are in good condition. Then we looked into tuning. So remember this, the more oil the engine keeps from burning, the more the lubrication it will recieve. And engine that is starved of lubrication, is sure not to last long at all. So tune the engine for what you want. Tuning will provide you with the best of power, or the best of longetivity. And for fuel. The higher the nitro percent, the hotter the fuel will burn, causing more oil to be burnt along with the fuel. In which causes the engine to starve more for lubrication. So choose what you want, greater horsepower, or longer lifetime. It's all in what you want to do.
One last thing, I'll add this now, since it's one of the major facts about tuning, and engine life. Overheating will cause the engine to lose it's life greatly. And engine that overheats is not getting enough lubrication. Running it while overheating will cause parts to wear and maybe even fail. So make sure to check you engine for overheating. A way to do this is to spit on the engines head, and see if the spit boils off instantly. If it does, richen the motor, and run it around at medium speeds to cool it down. And when I say richen it, I mean about 1/4 - 1/2 turn. Get oil in it, just don't shut it off. Shutting it off may cause parts to warp, causing vibrations, which in turn cause breakage. So keep your engine running cool so you don't overheat it.
Hope this helps NitroNewbie.
AoD
