EGT Probe Placement
I set up my TRX with the probe 6 3/4" from the face of the piston and dialed in the jetting from there. Since the time I set mine up I've had many TRX owners put their probe in the same location with comparable results. The Banshee seems to read a little cooler at that distance so it may be best to move the probes a little further away from the piston to get a more accurate reading - I like 7 1/2" to 8" on that engine. These silly-semi-supercharged two strokes spit so much fresh, cool mixture out the exhaust during the pipes suction phase it cools the probes - to the tune of about fifty to seventy five degrees for every inch it is placed closer to the piston. There seems to be a kind of "sweet spot" that can be noticed if attention is paid to the color of the exhaust pipe(s). Sometimes there's an area on the head pipe where it shows some discoloration from the engines exhaust heat - where that starts would be a bit too far down the pipe to locate the probe.
An EGT gauge is a tool. By itself it adds no power. In fact the obstruction in the pipe (the probe) probably robs some. The up side is that when used properly the gain is much more than the loss. The peak operating temperatures can be dialed in from almost any probe location. The trick is to perform a lot of plug chops to verify the reading from the gauge, then make adjustments to the jets accordingly. When someone starts to notice the changes in exhaust gas temperature due to the air temperature and/or quality and the changes in exhaust gas temperature which result from the changes made to the jetting they are becoming well-tuned to the real moment to moment requirements of the engine. It is often then, for the first time a rider will confidently jet the right direction and cure the "not quite perfect" running condition, without guessing.
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