Smoke, Smoke Options

[Boothy]

Cheers all!

Sorry, but I again need to ask for help.

New engine blowing smoke. 1.7 punched out to 2.0 with a big bore kit. Cam, Weber 40s. It started and ran pretty well late last fall. Used engine break-in oil as recommended. No smoke but sluggish acceleration -fine at high RPM.

With the warm weather (finally) I swapped out the Weber jets to the recommended .50, 1.50, and 1.95. Ran it up to 3300 with a timing light. I remembered I did static timing but not dynamic. Now it sounds pretty good but I'm seeing light blue smoke and a really black exhaust. I don't think the jets were that different but no markings so not sure.

My immediate horror was a broken ring -I really don't want to pull the engine again. It idles fine and sounds strong. I'll do a compression check. When it idles, there's no smoke. When I bring it up, it begins to smoke a little. Then it's consistent—no horrible but noticeable.

It sounds strong. It idles nicely at a 1000 and revs up fine. I'm hesitant to push it until I figure out what's going on. Changed the oil to 20W-50. Could it be, with the soot on the tailpipe, my jets are wrong? Stretch I know but hopeful. Heads are new so the oil in the guides shouldn't be an issue.

As always, thanks in advance!

[VaccaRabite]

Possible issues:
Rings have not yet seated.
Overfilled with oil.
Running way too rich after carb adjustment.
Timing is off.
Broken Ring
Broken piston.
Some combination of the above.

to do (in this order, starting with a DEAD cold engine. Like it has not run since the previous day cold.

1) adjust valves.
2) check your oil level.
3) Warm up engine. Drive car. Fixed? WOOO! If not, continue below.
3.5) adjust your timing. You need to set static timing AND total advance. You can't just set one and ignore the other. Pull your plugs out while you are up there. Take pictures of each plug end, and not what cylinder each plug came out of. Static timing alone isn't enough. Running too advanced is bad.

4) compression test (plugs out, throttle open, engine warm.) Post results. You are looking for a cylinder with a significantly different reading then the others. Compression on a newish engin3 should be above 130PSI each, and all cylinders should be within 5% of each other.
5) While the engine is warm and the plugs are out, do a leakdown test. This will tell you what percentage leak you have, and where it is leaking. Bubbles at the cylinder base mean your case is warped. Bubbles at the top is a cylinder leak. Bubbles at the valve is a bad seat. And air coming out of the oil tower indicates bad rings. Shit leak values on all cylinders means rings aren't seated yet. Shit leak values on 1 cylinder means the engine needs to come out.

Hopefully it was just overfilled with oil. But at the end of this testing you should have a very good idea of what your issue is.

Zach