Tuning Novarossi Engines
 

Lately, I've been having problems tuning a .12 NS12S3A1 and a .21 Novamega SX21 Ev2 engine. I'm using O'donnel 30%. Both engines overheated ranging an excess of over 300 degrees fahenheit. I kept riching out (turning counterclockwise) both engines but both still overheated. I've changed fuel tubing and riching them out until lots of fuel came out of the stinger. Air temperature was around 75 degrees fahrenheit. Anybody have a good tuning and troublehsooting guide?

I will check the clutch first. What about the engine idling temp? If it has huge different after running,sometime the problem is not from your engine.

Dino,

Yes clutch problem on my Serpent 950. It's having a hard time engaging. I followed the manual but still cannot engage that good. I've loosen the clutch for earlier engagement. It worked only a little. I think the flyweights are worn out. The NS12 has no clutch problems and everything looked good except the overheating. Thanks buddy!

About that .12 engine,you can try cooler plug first. What plug are you using and how many shims?

I'm using a hot plug and the weather is cooler here now ~75 degrees f. I'm using default shims. I haven't taken the engine apart yet.

check to see if you have any air leak! like pressure line and fuel line and check if there is any fuel leak around the carb, and such.

second thing is check your bottom end needle it might be too lean.

I've change the fuel and pressure lines but still no improvement. I'll start tearing the engine apart and seal it up with silicone. You guys think a cooler plug will work? Suggestions?

If you didn't adjust the compression,I think the compression setting is too big for O'donnel 30%. Add 0.1mm shim to delay the ignition timing. If not enough then also try cooler plug.

I don't know if it will fix your problem, but adding the head shim is a good idea. I got an NS12S3A1 from Steve O (he is a friend) and I know that he added the .1mm shim before he sent it to me on the assumption that I would be using 30% in the engine.

Add shim
cooler plug
check bottom end needle


+1

I'll start with a cooler plug and if that don't work then I'll start adding shims. Where can I can get more shims?