Evolution .52NX engine
last updated 11-3-2006

Back to Main Page

  
I first found out that while the engine looks kewel... it just does not fit in my Raptor 50v2. I had to use a grinder to take a few millimeters off the top of the heat sink so that it would not hit the fan shroud. After that I found that the centerline of the crankshaft is not the same distance from the mounting tabs as the TT and OS engines are. I had to drill out the bolt holes in my frame to allow the engine to be angled enough to align with the start shaft. I also found that the throttle arm would touch the header on my Hatori muffler so I had to rotate the arm around so it was on top. I do not like this because it makes for bad geometry. I do like that the exhaust port sticks out a little further. This gave me more room between my muffler and frames. Anyway so on to the test. The first thing I found was that the engine was too lean when I was in flight mode 1. In this mode I run about 1800. I tried richening the high speed needle but it had a limier that was keeping me from doing this. I tried richening the low speed but it did not help. So I went back to the bench and removed the limiter. I ran two tanks through it trying to figure out the tuning. It was behaving strangely.. ie. there was some weird interaction between the low and high speed needles. By the end of the second tank I had established that the high speed needle effects the entire range as you would expect. However the low speed needle effects both the low end of the throttle curve as well as the top end. This is not necessarily a bad thing.. just something I had to figure out. I hope tomorrow I can get it to run the way I want.

11-12-2006 The Evolution 52NX engine simply would not work with the carburetor it came with. After adjusting on it a lot! I got it as good as I could but that was no were near acceptible. I could get a good idle and top, but not mid. Or I could get a good mid but then the top 15% of the throttle would be supper rich. Maybe I just got a dud, I would hope they are not all like this one. Eventually I gave up on this carburetor and ended up taking an old one off one of my past TT50's. The carburetor is not a perfect match. There is a 0.017" difference that i had to work around. Once done I had the engine tuned in less then five minutes. Currently I am not sure what I will do with this engine. i have a friend that has a slightly used TT50 for sale and I think I will go that route. Even with this old TT carb the engine still has three other issues that may keep me from running this engine. First is the sides of the engine head are hitting the frames which I do not like but it can be fixed quickly with a grinder. Second is the crankshaft does not centerline the start shaft which I did a work-around by opening up the engine mount holes in the frames but I still have to work too hard to get the engine to align each time I put the engine back in. Third, the big head sticks down so far it makes it very difficult for me to unlatch the canopy clip. On my canopy clip i have a screw installed to prevent the clip from coming off in flight so I have to pull down on the clip before sliding it forward. With the big head on this Evolution engine I cannot get my finger behind the clip so I can release it. I have been through a lot trying to get this engine to work and in the end the power was not any better. The engine itself does have a clean combustion and runs smooth just like my TT50's. I get the same flight time of about 14+ minutes.