Originally Posted by fx-2
1.) I live on the Coast in Oregon it rarely gets over 70 here. The temperature ranges between 55 degrees and 65 degrees year round. Our humidity is always high and we are at sea level. I have been using a BP6HS NGK spark plug. Is there any advantage to going to a BP5 or BP7? If so why? No the proper plug it the one that run hot enough to burn the deposits off but not cause preignition or detonation . You have to read the plug . The carburetor must be jetted right then set needle for low an mid . Do not drill jet buy the right one , by drilling there can as much as 10% off so don't know where your at . Dan
Are you talking from experience or speculation.
I have soldered the jets on several of these, and many other engines. I don't understand what you mean by 10% off. I mean, If you can't drill a hole more accurate than that, you surely need to buy them.
I bought a set of bits that start out at.018 and increase in size by .003 consecutivly.
I solder up the jet with just a tad of solder. Then back drill it first with the largest bit that will take off no brass.
Then , on the first HT I did, I drilled it to .018 and tried it. Too lean. Drilled the next size, too lean again the 3rd size ect. until I got it in the range that I could fine tune mixture with the needle clip.
Way easier for me anyways, to solder them right now than source them and wait.