I have read several threads on this and two different theories seem to abound! The first says that you never need to shim the plug as there is no way it can go too far and enter the combustion chamber and hit anything. Another says that due to varying tolerances with that part of the engine it could happen so you need to test the plug as in how far it goes into the engine and copper washer it if need be. I seem to remember a fella called Jess was explaining it this way but don't hold me to it. Is there one answer fits all, or is it a grey area that people will always disagree on? I am about to buy the plug and adaptor and as total bird brain with rotaries don't want to damage anything. Thank you for any views on this.
It staggers me that "theories seem to abound". It's so simple.
Listen to the guy called JESS. He manufactured the plug adaptor and would beis the most experienced RE5 guy on the planet. Jess on FB and Jess on here are the same person.
While you will NEVER hit the rotor, it does not therefore follow that you don't need to shim. The issue with shimming has nothing to do with going into the combustion chamber. The reason you are shimming is because screwing the plug in too far will damage the plug when it hits the bottom of the well. You'll never hit the rotor, you won't damage the engine. But you'll bugger the plug. You'll crush the electrode, the bike will either not run, or run badly. The only way to find out is to test fit a plug by hand and feel if it gets resistance before reaching the end of its threads. Or screw it in, screw it out and check the gap hasn't changed. And look very closely at the bottoms of the electrodes to see if there are any faint hints of damage such as copper coloured witness marks or dirty oily marks.
Any doubt, shim it. And by the way, all this stuff originated on this board years and years ago. The guy who made the adaptor is on this board, the guy who found out about the tolerance differences is on this board and the guy who came up with the solution is on this board. It was all dealt with here a long time ago. There is no controversy. We all know what's going on.
Yep but when you hear two versions of something, as a novice, you are bound to wonder which is right. I am a fully qualified sports coach and when i hear some ''facts'' relayed to me i chuckle as they are often 180 degrees to the truth. Anyway thanks.