Jaybird, The method you described is not really accurate. Try this link for the correct method. http://www.strappe.com/plugs.htmlI've heard a good indicator of correct plug heat is the blackening of the first three or four threads
KxKen, You are right.believe plug readings are only reliable for a WOT test to determine where the main should be. Pilot and needle clip should be done by feel. This is what I've been told by people that know allot more than me (which may not be saying much).
To get a proper reading on a main jet you must examin the base of the insulator where it joins the metal shell not the insulator tip that as is mentioned in the article. A two stroke jetted to the edge and running a high quality fuel/oil combo will have an almost white insulator. As far as the heat range things go, the factory speced plug is way conservative in MOST CASES so useing a colder plug is not necessary. In many cases a hotter plug can be used. My advice would be to stick with the stock plug and jet it correctly then check to make shure you have the correct heat range.In that tutorial it's mentioned that the correct way to tell if you have the correct heat range is if the insulator is nearly cleaned of deposit. Thing is, when we add our two stroke concoctions to the mix, it seems a fine line between needing a hotter plug or a main jet tweek, and how do we distinguish between the two?
The procedure for each is different. For the main jet the bottom of the insulator is examined, for heat range the tip of the insulator and the ground strap is examined.I have the base of the inlulator concept down, but how does one tell if there jetting is correct if the same procedure to check both the main jet, and the heat range is the same?
If the heat range of the plug is too hot it can cause pre ignition. This can occure at part and full throttle, but it is most likely to occure at large throttle openings.I'm having a hard time with this one....I've always thought my upper circuits would run even with a slight discrepancy in heat range from the plug...it's the lower slower circuits that need the range correct. Am I off base here?
I think so.I would like to hear someone weigh in on the thread black thing...have I been wrong to think that heat range has something to do with the blackening of the threads?
We use cookies and similar technologies for the following purposes:
Do you accept cookies and these technologies?
We use cookies and similar technologies for the following purposes:
Do you accept cookies and these technologies?