Its confusing I know. I can think of at least 20 engines that would fit the bill and all of them will perform well. In this day and age, this hobby revolves around reputation. Word of mouth is very important and it can make or break a product or service. Everyone has opinions and they are derived from personal experience and words from others they trust. While there are a lot of products to choose from, one thing I would suggest is not only listen to what is being said on the internet but also what you hear and see trackside. A good thing to do is go to some local races if you have a track close by and see what people are running and talk with them one on one, watch the engines perform on the track and when you start to see a pattern forming as to what performance envelopes you are looking for, that should help narrow down as to what engines you are looking at to purchase.
While many of these engines are similarly priced, one thing to look around for is overall quality. The biggest thing is carbs. A carb can make or break an engine depending on its overall design and quality. I have seen engines that ran outstanding but required a carb change to make it happen. When buying an engine, the last thing on your mind should be looking into what other carbs are available to put on your new engine because the one it comes with is not going to work well. The companies that I have experienced that make some of the best carbs are Novarossi and OS. A lot of people love OS because of their performance and tunability but a lot complain of low life expectancy. I myself have had a few vspecs in the day and all of them were catastrophic failures by the 4th gallon for different reasons. I have seen local guys get 8+ with no problems and they swear by them so it all comes full circle to overall experiences. I have dealt with Novarossi and Picco for years and have had great luck with both but others have not for their own personal reasons.
The biggest thing is to take care of it. I have seen people take the best engines available and kill them inside of 2 gallons because they didn't treat them right. If you break them in right, preheat the engine before each and every start, maintain a good tune and inspect wear on moving parts, replacing them before they actually fail, you shouldn't have too many problems out of most engines available.
The only other piece of advice I can give you is too shy away from relatively new products. I am not saying every new product is bad but there have been a lot of products that got rave reviews early and ended up flopping later because of inferior designs, materials etc.
All in all, the engines I would buy in your price range would be the N21R, P5 and the Plus 4. The new Picco based engines look pretty good. The new JL engine is made by Force and I never liked Force engines so if was me I would spend the extra $50 and get a JPX .21 or something similar is you want to go the Picco route. I can get you a race ported N21R for the same price and it will perform right up there with the new JL .21 so the only decision to make us what brand you want. I used to love the RB line but when they switched companies, I have shyed away because of past experiences with engines that were not made in Italy. I am not saying they are not good, I am just not taking the chance to find out. I am a Novarossi dealer now so I don't really want to run anything else at this point but I have run Picco's in the past and they always treated me well and their performance was hard to beat.
Last edited by PowerHouse; 12-19-2009 at 02:29 PM.