Blue smoke after rebuild

[rustybronco]

Rob, I think Ed, (nessism) posted the valve to stem 'wobble' spec's on here recently. Might try poking around and see what you can find.

[azr]

Well looks like I've got to tear into the top end yet once again this is really starting to wear me thin. Started her up this morning and it's as if I started a leaf fire there's so much blue smoke. I'll look at the valve stem seals and see if by chance I cracked them putting them in. I'll measure the valve stems some how and make sure they're not out of spec and look at this 'wobble' thing. I think I'll take it right down to the pistons..again..... just to make sure I'm not missing anything. I'm wondering if this could have something to do with me lapping the valves?? not sure how but I'm grasping at straws now. Very disappointing.

[rustybronco]

Measure clearance in two directions. X and Y, perpendicular to each other, by rigging up the dial gauge as shown...

Int std... .0009~.00022 service limit .0035

Exh std .0016~.0028 service limit .0039

Double check the service manual to be sure.

[azr]

Well she's all back together. Took her down to the base, put in some new rings this time. Pulled apart 3 different heads and kept the thickest 8 valves I had. Checked the 'valve wobble', largest measurement was on one of the exhaust guides, .008, the rest were all below that. Put in a new set of valves guide seals and this time the only force I used to put them in was my thumb. Lapped the valves and buttoned her all up. Went for a ride to seat the rings and she's running pretty well as usual. Came home and a good sign was all the plugs were a nice tan colour, not one had any oil on them which they all had before, so far things are looking positive. The real test will of course be in a couple of hours when I cold start her. If I get a cloud of smoke I think I'll take a gun to it Thanks for all the help as usual guys.

[tkent02]

If I get a cloud of smoke I think I'll take a gun to it

Let Schweissy do it.

[azr]

Sat for 2 hours, fired her up and NO BLUE SMOKE!!! finally.....sure learned somethings thru this that's for sure. I've got to tear apart my 78' 1000 as she's pushing smoke from rings and valve seals. It 'should' go a little smother than this one, ha,ha,ha..I hope.

[azr]

Well, unfortunately the bike is still pushing a cloud of smoke. I started her up this morning and exact same as before, blue smoke from both pipes. Unfortunately there's nothing more I can do, I really don't know what's causing this. Anyways, I'm done. I'm going to change the oil and just ride it. Who knows maybe it'll clear up over time.

[rustybronco]

How big is the cloud of smoke upon startup?

Is the bike running rich on clod start? Excessive fuel will show up as blue smoke; not a cloud mind you, but blue tinged white smoke.

Plugs are tan? that doesn't indicate oil burning.

Agreed. Ride it for a while and see what she does.

[tkent02]

Can you show us a video of this smoke on a cold start, taken from a little ways away?
I'm curious how much and just what it looks like.
How long does it smoke and when it does stop smoking is it completely gone?
How about if you start it from cold with no choke at all?


Wht are you thoughts on breaking in the new rings? Ride it hard? Baby it?
What have you done so far?

[stetracer]

Any chance you put some rings in up side down. That will make it smoke

[azr]

Took her out for a ride this afternoon, put her through the gears. The bike really performs well, and so smoooothhhh. Anyways, started her up and a cloud of blue smoke, basically like you're starting a small pile of leaves on fire. I immediately dropped the choke and it did help but mostly I think the smoke decreased due to the drop in RPM, interestly enough the smoke disappeared a lot quicker, maybe half a minute or so. Ran it through the gears on the 60km ride. Came home and there's no smoke of any kind while it sits and I throttle it, again I'll try starting it cold later tonight or tomorrow morning and see what it does with no choke. Pulled all the plugs and they are all a perfect tan, very nice to see. My idea of seating the rings is ride it hard, lots of different RPM levels, hard accel. and hard decel. There is no chance I put the rings in upside down, lol, believe me I checked.

[chef1366]

If it did not smoke right after the rebuild the wobble on a valve may have taken out a seal. What plug has oil on it? Is it the same cylinder that had the valve that wobbled?
What about a cracked head? All the rebuilds has used the same head right?

[azr]

None of plugs have oil on them now. I checked the head as close as I could trying to find a crack but didn't see any I doubt that's the best way to find a crack. Yes all the rebuilds but the first one have used the same head. The first head never had any blue smoke on cold start but I can't use that head as it kept breaking cam cover bolts, 4 in total.

[stetracer]

There is no chance I put the rings in upside down, lol, believe me I checked.

Nope, Not if the smoke goes away completely after running it for a while.
It has got to be the valve guild seals. For reasons already mentioned valve wobble will make them leak. Everything is stock motor parts? Is there a chance you got the wrong size valve guild seals or they are getting damaged on install. But your gonna have to pull the head to check the valve wobble.

[azr]

Second cold morning start up. Started her up without the choke, a lot less smoke but still some blue smoke. I ran it for a very short time without the choke then started her up with the choke, about the same amount of smoke, maybe a bit more but not much. Overall there was a lot less blue smoke this morning than yesterday no doubt about that. I'm going to consider this problem 'fixed' for for now anyways. I'm going to change the oil now and then in another 500km or so and at that point I'll report back with any changes, be they improvements or not.