First of all I would like to say this about these jets. Their not what they appear to be. I was having the standard problem of bogging at 3/4 to full throttle. From reading I figure I need to rejet. I go on line and find a dealer who could supply me with some jets. I'm told the the standard jet is a #70. Without knowing which way to go (larger or smaller) I order 3 jets from an unnamed supplier. I order a #68-#72-#74. Let me first clear this up, the higher the 2 digit number the smaller the hole in the jet. The #68 jet is supposed to measure .031 but it measures.028. The #70 jet which was the stock jet in the carb was supposed to measure .028 but actually measures .026. The # 74 jet was supposed to measure .022 and it measured .029. As you can see these have no consistancy what-so-ever. I used my micro bit set that I calibrated with my starrett micrometer and the bits are spot on. what i'm getting at here is if you think your putting a larger or smaller jet in your carb. Chances are you mite not be. The numbers are stamped on the jet itself and 100% of the jets i bought are wrong. I took the jet out of my carb and replaced it with another one that came in with what I ordered and it works great. I don't know how big it is because I didn't mic it before I put it in. but I can pretty well guess it's not a #72 I'll have to check it next time I have the carb off. As for the answer for the bogging problem. I would say get yourself a micro bit set (about $15.00) and get a few #74 jets. those jets will be the smallest you would ever need. Then start working your way up the drill index until you have the problem solved. you only need one jet to keep drilling bigger and bigger. If you get it too big use another jet and go back one size. You can always solder the holes shut on the jets you drill too big. Any questions. others mileage may very. This is just my observation.