Quick question about running rich.

[LongboardMalinois]

So my bike is about halfway through break in, and it is 4 stroking a lot. It has a little band at about 1/4 throttle where it runs properly, but the rest of the time it 4 strokes. My question is are there any serious problems which arise from 4 stroking, and should i wait until the end of the break in period to tune the carb? Also i am using up the last bit of my 16:1 gas mix, i am switching to 24:1, will that help? Thanks!

 

[YesImLDS]

Don't bother tuning while it's breaking in if it's rich. 16:1 is also a ridiculous amount of oil. You might try 32:1 which about everyone will recommend around here. That would lean out the mixture a little bit and might solve your problem. If the problem still persists then tuning the carb would be ideal.

 

[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.

 

[LongboardMalinois]

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?

 

[Agreen]

You can find the NGKs here:

http://lmgtfy.com/?q=Ngk+b6hs

It's all about getting those rings seated man. You can do it at a rate of once every other revolution, or on a one for one basis.

 

[Davezilla]

Just gotta remember that extra fuel is there to help keep things cool during the break in period, but it's probably safe to drop the needle down a notch and jet down one size since these things are so crazy rich right out of the box. You also need to consider any aftermarket add on like free flowing air filters, x chamber pipes etc... basically anything that let's the air get in or out easier can require a jet size up to run proper as well. There are a few reasons not to tune during break in but if you do, just be sure to keep an eye on your temperature or keep the trips short enough that the engine can't get that hot.

 

[Agreen]

While i understand that rich is safe and lean is mean, there comes a point when it's too rich and that "washes" the compression away. A little bit more lean will eliminate the 4 stroking, and will not tear anything up. Once it's all broken in you can fool with the jet size some and you'll see how much more power you can get.