Black smoke during break in

[90GSX182]

I just passed the 300 mile mark on the break in and I took it on the highway to do some light pulls. I had it in 4th and got it up to about 3500 rpm and when I let off the gas I had a lot of black and grey smoke come out of the tailpipe. im only running about 7psi. Is this because my rings havent set yet or what?

 

[Sivad87]

I just passed the 300 mile mark on the break in and I took it on the highway to do some light pulls. I had it in 4th and got it up to about 3500 rpm and when I let off the gas I had a lot of black and grey smoke come out of the tailpipe. im only running about 7psi. Is this because my rings havent set yet or what?

is it tuned properly? Boost leaks? if its shooting out grey/black smoke your A/F ratio is wacked out for some reason or another. Since you just rebuilt the engine, i would check over the whole engine a couple times to make sure absolutly everything is right. sometimes you can look over little things and not know it. If you concerned about the rings not being set properly then do a compression test.

 

[Vallary99]

You're running way rich, hence the black smoke.