Here is a quick tuning reference guide that was sent in by one of our posters. Hope it helps!
Originally Posted by Nitronaught
Hi I’m Nitronaught,
I have some tips that I have gathered that will help you tune your Traxxas engine, especially if you are new to nitro motors. If you still are having problems feel free to post it in the forum or consult Traxxas, here is the link for Customer Support. http://www.traxxas.com/support/index...cat=127&id=449 These tips and practices are for the Traxxas 2.5, 2.5r and 3.3 motors only, they are not a replacement for the Traxxas method of tuning your engine, they are provided as a quick reference.
1. If you have other hop ups, like a high performance pipe or air filter, hold of on installing them until you get the idea and practice of tuning down, any change you make to the motor will change how the mixtures are set, so get tuning down first, hop ups will follow. The Traxxas tuning guides and settings are based on stock motors, any change you make can and will affect the engine mixture settings.
2. Always tune with ½ a tank of fuel. The mixture progressively leans out as it nears empty, and tuning with ½ tank can help with overheating problems when the tank is near empty.
3. Tune in small increments. No more than 1/8 a turn at a time on the HSN (High Speed Needle), 1/16 a turn on the LSN (Low Speed Needle).
4. Use a fresh glow plug, especially after break in. Use a Traxxas 3231 or 3232 Super Duty plug. In the event that these are not available to you, the McCoy MC59, Megatech ‘Q’, OS LC3 (DuraTrax LR3) are known to work well. And always clean your motor good before trying to replace your glow plug, all it takes is 1 grain of sand to shorten your engine life.
5. Use fresh fuel, I prefer using 20-30% Nitro and if you are new to tuning Traxxas Top Fuel is formulated especially for Traxxas motors, if Top Fuel is not available consult your Local Hobby shop (LHS) for what they recommend.
6. Always tune with a warmed up motor. Always do a WOT (Wide open throttle) pass in between any adjustment no matter what needle you are dealing with, it help regulate the motor.
7. You have 2 mixture settings, Low and High speed. They work together. So you must tune them both in order to get good results. Many who post here don’t. Probably 90% of all tuning issues I have seen is because they do not touch the LSN.
8. Tune in this order. HSN, then LSN, set the idle, then HSN again, reset the idle if needed.
9. Use a handheld temp gauge at first as a reference. From there you tune by smoke trails and performance. You must have a visible smoke trail at top speed, if not - the HSN is too lean. Temp gauges are basically a tool for getting you in the ball park without frying your motor. Smoke trails and performance is used as a reference for the fine tuning part.
Pinch test for setting your LSN
1. With the motor warmed up do a WOT pass then pinch the fuel line 1-2” away from the fuel inlet of the carb and count how many seconds it runs till it stalls out completely.
2. Less than 3 seconds it’s too lean, richen the LSN by turning the needle counter clockwise, if it is more than 4 seconds it’s too rich, lean the LSN by turning the needle clockwise (remember no more than 1/16 a turn at a time.)
3. Engine RPM’s should rise slightly before the engine stalls. If there is no rise is RPM, the LSN is too lean, if the RPMs rise a lot, the LSN is too rich.
Again if you still are having problems post it in the forum, tell them what temps you have, what motor it is and what symptoms you are experiencing, or contact customer support at the link above.