Re: Smoke from exhaust after idling

Posted by fredkanter On 2016/7/6 8:15:27

The rings seal against the cylinder wall, the addition of a bit of oil which is viscous helps the seal as the viscous oil will prevent most of teh air from leaking by the rings.

Oil put into cylinder = increased compression = leaky rings


Oil put into cyl = little change = rings OK

The valves are distant from the cyl bore and the oil neither reaches them nor affects them.

If compression is still well below norm with oil in cyl=
leaking valve or valves.

Backfiring at speed

1. Timing too far advanced
2. Lean mixture
3. Intake valve not seating quickly enough due to junk in the guide
4. Maybe it happened on July 4th???