Originally Posted by Agreen
Actually, you're not doing much for breaking it in if it's running so rich that it's 4 stroking most of the time.
Before re-jetting the carb (which is stupid simple to do) check that:
-The needle in the carb is properly placed. Most people find that putting the clip at 2nd from the top is best. This controls idle to 3/4 throttle. Above that is main jet.
-Change the plug with an NGK B6HS. Grab a few of them, because when you're done breaking the engine in, you'll need them to properly tune the engine (search for plug chop)
-Did your CDI come with that cheesy plastic boot, or a nice supple rubber boot? Some people are finding better quality spark plug boots these days, but if you got a crappy plastic one, you'll want to change it before you have bigger issues.
-I forgot to mention plug gap. It's approximately 0.025". Between 0.023 and 0.026 is the most appropriate gap for these little guys.
-Torque the head bolts. Still rockin the acorn nuts on the head? Shame on you...
-I ran 16:1 ratio for a bit, but never got it above 15 mph during break in. I didn't notice any issue with it other than the massive amount of smoke the engine produced. I started running 32:1 after about 100 miles, then I worked down to 40:1. I use regular 2 stroke oil (tcw-3) since it comes in gallon jugs pretty cheap, and I use it in my boat and Rx7.
Why would it not be breaking in properly if it is 4 stroking? I thought that breaking in entailed setting the rings and polishing the cylinder. And my bike hardly smokes at all once it warms up, even with the 16:1. My CDI came with a good spark plug boot. And where do i find the NGK B6HS?