Egli (a german firm, I think) makes a 612 screamer kit for the 500 RE. If you can read German, or have a translator, go to their website...... Dew.
The 612 kit is a good one, but is not for the faint of heart as it is pretty involved. You will need to split the cases, replace the crankshaft, do some machining (filing), check clearances between piston and valves, etc. If you are familiar with engine rebuilding (theory as well as having put together a 350 Chevy or minibike motor) you will be fine, but if you are a beginner we do not recommend it. You will find more details here: http://www.royalenfieldusa.com/performance-612cc-p-6568.html
Good attitude.But I'm afraid that the experience gained by taking the engine apart is limited to taking the engine apart.Getting the engine together again and running is another experience altogether.The nature of the beast is that you are going to run in a myriad of nagging little issues which you can't solve on your own if you haven't seriously worked on an engine before.And nobody will want or be able to do the job for you.So my advice is to take it step by step.If you don't heed the advice, you need to be prepared to have your cycle down for a very long time.And that's all there is to it, you won't be able to ride for a long long time.Peter
As you know we sell many of these kits.
I'm surprised there is not more buzz about the kit online, it really is pretty popular with the more ambitious modders.
I need to convince mine I NEED a bike in the first place. She thinks we should have a bigger house for our almost two-year old to run around in. unfortunatly I kinda agree...