That almost positively sounds like a leaning issue. It sounds as if the motor isn't getting enough fuel, and the lack of a decent smoke trail at all shows that it's just not burning fuel. Personally I'd richen up the HSN and see if it fades out a little. If the effect is reduced, there's your answer. Trial and error my man, but here's some info to help ya!
I'm gonna list some thing to try to get that engine running right.
1 - New Glow plugs... Always have one just incase. A glow plug can cause so much trouble that it should be illegal lol.
2 - Factory Settings. Set those needles back to factory, start tuning again. Run it at stock first, get a good dose of fuel down the pipe and see how it runs at factory. Believe it or not, I've actually seen a Picco .21 from factory be set too lean for throttle. It's rare, but possible that the needles aren't nearly right. So take it to factory by the manual, and see what it does.
3 - Still problematic? Take the time to check the fuel. Check the fuel lines, tank, throttle assembly, all the bolts, the glow plug, even the exaust! Check, and recheck every possible problem. I've seen where an air leak in the manifold - Pipe sleeve caused an extremely rich engine, even when running at super lean settings! Check again, and again.
4 - Other tips? Tune in this order. HSN, LSN, then use the MSN to fine tune the rest. Only tune in that order. If you need to make adjustments from factory to start it, then go from there. Finding the right tune can be a long and time consuming process but is worth it, trust me.
5 - Other things to look at? Try a different plug type, or different fuel. My TRX .15 pro literally hates trinity monster brew, and run Odonells racing blend like a champ. Probably mainly due to the oil content, but it's worth looking at. Also, the TRX runs better with an OS plug then it does with the stock McCoy in it. Plug temps are also a big factor. Remember this as well.
Warm temps, run a cold plug
Cold temps, run a warm plug
A couple other things to remember. These engines wear over time, and with this wear comes the need for retuning. I retune my mills every time I run them. Every degree in temperature, and even a foot in elevation causes ever so slight changes in air intake. Running the right tune for the environment your in is key! On a 90 degree day, you might run 1.2 turns in, and on a 50 degree day you might have to run 0.5 turns in. It all depends on the environment you are in!
Another good idea to look at, air filters.. I can't remember how many times I've seen people have problems with their engines be a result of the air filter. Most of the time, it's just an ignorantly filthy filter, but that's not always the case! Some people just don't know when to stop with the air filter oil either. HPI's instructions should be avoided as well. One capful of oil can mean anything. I've seen some giant caps on air filter oil before. You should just go with about 20 drops and work it into the base filter. Then put about half of that into the outer filter. This way, the oil isn't constricting the airflow either.
Remember, these engines are incredibly simple, air and fuel. Just look at how they work and try to understand what makes them tick. Once you realize the method they use, it's easy to recognize problems from there. 🙂
I hope this helps you out bud. Let us know what happens.
