Yup as Joe and Jester noted above and here are some additional things to avoid the tell tale black rings that you see so often walking down the flight line. Lets look to the starter and its rubber cup. Many old used starters have old hardened rubber and possibly poor cup shapes that does not fit the spinner properly. Also there are new rubber inserts of poor quality (to hard) The best are the silicon rubber inserts that it is easy to push a finger nail into. Cone shape is important that it fits the spinner properly. There are cone shapes that are intended to be used with bare nuts on a crankshaft and these may not always be best for use on spinners or spinner nuts.
Next thing is technique, It is very important that the axis of the starters shaft is held in line with the axis of the engines shaft. This is often done carelessly and indeed causes problems. The next point of technique is that sufficient pressure aginst the engine must be used and that means its best for someone to hold the airplane and you use two hands on the starter. Holding the airplane by one hand and one handing the starter is often very difficult especially in the case of an engine with a tight choke such as and LA. Yes it can be done if the engine is properly wetted out before spinning the starter but requires good technique.
Now lets talk about plastic spinners, They run anywhere from OK to pathetic and exploding spinners usually at the start but even at other times is not uncommon. The very best plastics are the type with an aluminum back plate that has a capture channel for the plastic but even they are subject to the evil ugly black ring unless you do every thing right, every time.
Now for that evil opinion thing, yes mine: For anyone starting out particularly with glow or gas airplane throw away that pretty spinner that came with the airplane or give it to someone you don't like (no on second thought thats too mean). Spinners, especially plastic spinners are all to often responsible for lost flying days also just because they take up so much time simply replacing a nicked prop.
Instead a much better choice are 'spinner nuts' they allow prop changes in seconds, look far better on any airplane with open fronted cowl cheeks as on most trainers and many sport airplanes. and they fit many starter cones properly. The evil ugly black rings will be a thing of the past. They are typically around nine bucks.
John
http://www3.towerhobbies.com/cgi-bin...&I=LXE158&P=ML
