Virginian
Member
I may be ignorant, but what is "4-stroking?"
Determining Main Jet Size
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AussieSteve
Active Member
Hello Virginian, I doubt that you're ignorant - 4-stroking is a very specific term.
A 2-stroke engine '4-strokes' when the fuel/air mixture is so rich that the engine can't fire on each revolution and instead fires on every second rev, like a 4-stroke. (It's an indication that the slide needle is set too high or that the main jet is too large, depending on the throttle opening that the '4-stroking' happens - if at 0-3/4 throttle, the needle is too high, whereas if it happens at WOT, (wide-open throttle), the main jet is too large.
There's a really good video illustrating 4-stroking better than I could possibly describe it here:- 4-Stroking {YouTube 6:15} (Well worth watching.)
You might also find this thread useful:- NT Carb Tuning Basics
*** I'm assuming that you're talking about a Chinese HT engine, although '4-stroking' applies to any 2-stroke, (or for that matter, a properly-running 4-stroke engine).
A 2-stroke engine '4-strokes' when the fuel/air mixture is so rich that the engine can't fire on each revolution and instead fires on every second rev, like a 4-stroke. (It's an indication that the slide needle is set too high or that the main jet is too large, depending on the throttle opening that the '4-stroking' happens - if at 0-3/4 throttle, the needle is too high, whereas if it happens at WOT, (wide-open throttle), the main jet is too large.
There's a really good video illustrating 4-stroking better than I could possibly describe it here:- 4-Stroking {YouTube 6:15} (Well worth watching.)
You might also find this thread useful:- NT Carb Tuning Basics
*** I'm assuming that you're talking about a Chinese HT engine, although '4-stroking' applies to any 2-stroke, (or for that matter, a properly-running 4-stroke engine).
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