Still smoking :(

[jkosakowski]

Ok my 400 has a fresh 407 bore and fairly new valves and new valve seals. Problem is its still smoking on startup, do you think it could be the valve guides???

[CJM]

Possible.

Whats your jetting, 407 should be roughly 160ish if that.

Sure its not gas?

[DragonGunner]

After rebuild it will smoke to burn off oil in the rings....after that, if you were burning oil before, your pipe an exhaut could have a little left over to burn off....not sure how long you been running since rebuild....could be valves, stems....if replaced not alot you can do. Black smoke or white...black is usually oil...white is usually gas...

[jkosakowski]

I checked the plug and it is pretty rich so I'm Gona put a smaller jet in and see if that helps.

[Zakradu398]

I have the same mods except no lid and I'm at 165 main and 42 pilot. I have a 168 and 170 on their way to me though cause I feel I'm a tiny bit lean.

Elev. is 1200ft btw

[xtreme762]

Regardless of jetting. You gotta break that stuff in, man. :D

Break in (http://www.mototuneusa.com/break_in_secrets.htm)

Good luck

Blue smoke = gas
Black smoke = gas
White smoke = oil

:fact:

[jkosakowski]

Oh believe me it's broken in I've done a few motors :)

[JOHNDOE83]

A air cooled motor will only be to rich when it stutters at the point where its to rich.

Until the stutter is present, it will be burning the proper amount of gas, light black smoke at idle and under heavy acceleration is perfectly normal and a GOOD sign.

Plug reading is no longer effective and is no longer a way to tune a motor, the gas additives make it impossible for accurate plug reading. simply pulling out the plug without cutting it open will only show you needle, pilot jet and timing.

You do not need to check a plug to tune these settings.

[400exwhipper]

Blue smoke = oil, not gas
Black smoke = gas
White smoke usually means your lean

[xtreme762]

Originally posted by 400exwhipper
Blue smoke = oil, not gas
Black smoke = gas
White smoke usually means your lean

I stand corrected.

You're right, blue smoke is oil. It's also present is a rich A/F condition.

White smoke is also oil! It could also be coolant. But we obviously don't have coolant..

White smoke is also a sign of a lean condition in a DIESEL engine. But we don't run diesel.

In rare circumstances, white smoke can also be moisture in the crankcase.

A small read:

Smoking Engine (http://mgaguru.com/mgtech/engine/be104a.htm)

So, really, we're both right! :eek2:

Have a good day.

[400exwhipper]

Some interesting things in that read! Either way you don't want to see blue or white smoke haha