[aceltr]

should a newly rebuilt eng smoke at all if so for how long

 

[jaradbailey]

it shouldnt smoke at all after a correct rebuild, unless the oil is leaking through the valves

 

[TRX2fiveO]

Well sometimes a new engine will smoke some from all the cleaners and chemicals used in the cleaning process but it should clear right up usually after the rings have seated into position( break in) run it for a little bit (2 or 3 hours) nothing heavy then change the oil. If it smokes still then you have an issue eg. ring spacing, valve seats

How bad is it smoking and how long after the rebuild?

 

[tomgodd]

Agree with Moose.

 

[Redracer]

How bad was it before the rebuild? I have seen left over oil residue in the header cause mass blue smoke. If your rings were shot before it is possible that you got enough oil in the header to cause it.

 

[Saber6]

Some smoke will be normal on a rebuild depending on your assembly lube.I also agree with Redracer the spark arrester and baffle may have oil still in it and that can take some time to work itself out.

 

[aceltr]

well there was only about have a piston left. Bent valves
had to bore .40 over. Replaced valves all new valve train complete top end
its just a little smoke but its enough for me to notice but only run it about 15 min
so if it oil in the pipe that should burn out. Right?
If the ring aren't seated how long should that take 2 hours ?
so after that if it still smokes there is a definate problem. correct

 

[TRX2fiveO]

15 min isn't long enough for break in run it longer and change the oil and filter this will remove any impurities , oil in the exhaust will take awhile to clear. let us know

 

[Saber6]

Two to five hundred miles is frequently required to completely break-in a four stroke.The smoke should be gone at this point. I dump the oil and filter in a four stroke after the first 75 miles, again at 200 miles, 500 miles, 1000 miles and each 1500 miles