Spark plug analysis, black liquid in tailpipe, rebuilt engine.

So i was riding with my friend last night and he noted i had some white smoke puffs coming out on deceleration of my bike left cylinder exhaust.
Nothing crazy just small puff amounts.
I have had no problems with my plugs being fouled etc.
Bike starts everyday
The engine i have in is My XS2 engine and was recently rebuilt by myself and i made sure to change out all the seals and gaskets and everything out of spec.
So valve guide seals were replaced.
The rings were not out of spec but replaced anyways.
I did not change the guides because they were up to spec.
I did everything by the clymer book
So i have an XS2 motor with bs34 carbs on that motor.
The motor has been in for 3 weeks now.
Running great.
Compression great
The bs34 carbs were actually rebuilt about 6 months ago from a shop in the city when they were on my 1980 motor.

That being said it also throws out some smoke on throttle blips same cylinder.
I looked in there today and noticed wetness. I tried smelling it but my nostrils are shot right now.
I am under the impression my float height may be a little off on that carb.
Though i am looking for some other opinions.

i haven't got home yet to see what my float height is on that carb so i will be checking tonight.
Just looking to see what ya guys think.

Just a few thoughts.
During break-in on new rebuild, retorque head, replace plugs (can get micro metal specs), tune-up (adjustments, timing, ...etc)
Feel inside left exhaust, if sooty/dry, may be just fuel. If slimy, oil's in there.
If enuff fuel gets in that left side, it could dillute the oil and that could give an oil indication, which could be interpreted as a false cylinder damage.
If fuel to that side is okay, then it's pumping oil. Rings on that side may not be fully sealing, could be riding on glazing (which usually only happens on over-gentle break-in, glazing develops before rings fully seat, rare, but happens).

Those are the optimistic thoughts. The other thoughts involve another teardown...

Another pic

Well, the plug ring/base looks clean, like it's been fuel washed. The porcelin, tip and lug look hard/black/shiny, usually a sign of oil, and not hot enuff to burn it off. Don't reuse that plug. Shows that you have a problem, not enuff info yet to figure...

You mention replacing the rings, but did you hone the cylinder too?

You need to hone a cylinder when installing new rings.

Did you measure the cylinder to make sure it was still within spec (just because the rings were, does NOT mean the cylinder is)? You need to measure both the bore diameter and roundness.

Out of spec cylinder would cause the problems you are describing. I have had out of spec cylinders that smoked and blew oil, but still had compression within spec.

i had the cylinders honed by a shop.
I did not own a hone and I felt more comfortable having a shop do them anyways.
I have since purchased one that one of the guys on here recommended
I measured the cylinders myself and then I had the shop measure as well. before and after the hone.
speaking of honing I read this article
http://www.snowvalley.20m.com/bikes/dnthone.htm
after the fact that they got honed

that being said I put the new rings in and checked the end gap.

.029 after honing with new stock rings so it was a close call whether or not to go the next size up and file the ends but I had stock size at the time so i put them in.
all were spaced correctly 120 degrees from each other.

funny story.... i had one of my friends try and smell the smoke when it came out..
he said it smells like fuel but who knows.

Though today riding to work I did not notice as much smoke coming out on deceleration and blipping. Its still there but not as much so I am clueless...
I am about 200 miles on break in. Everything has been checked over re torqued oil changed.
So maybe the rings are seating themselves.
I have yet to take the carbs off and check float bowl height been busy with work and getting ready to go to europe to visit the Ladys Family
but I will for sure do it when I get back.

Bike runs great though and I have no complaints pulls hard sounds great.
Starts up first kick 90% of the time
the other 10% two kicks.
Pamco and HHB PMA are just F*cking amazing

theblackassassin said:

i had the cylinders honed by a shop.
I did not own a hone and I felt more comfortable having a shop do them anyways.
I have since purchased one that one of the guys on here recommended
I measured the cylinders myself and then I had the shop measure as well. before and after the hone.
speaking of honing I read this article
http://www.snowvalley.20m.com/bikes/dnthone.htm
after the fact that they got honed

Click to expand...

I understand and agree with the controlled SAE tests, but I have serious problems with this accompanying 'infomercial'.

theblackassassin said:

that being said I put the new rings in and checked the end gap.

.029 after honing with new stock rings so it was a close call whether or not to go the next size up and file the ends but I had stock size at the time so i put them in.
all were spaced correctly 120 degrees from each other.

Click to expand...

.029" is too much gap, your oil may be coming from here. Almost sounds like you've got stock bore rings in a 1st over cylinder.

theblackassassin said:

funny story.... i had one of my friends try and smell the smoke when it came out..
he said it smells like fuel but who knows.

Though today riding to work I did not notice as much smoke coming out on deceleration and blipping. Its still there but not as much so I am clueless...
I am about 200 miles on break in. Everything has been checked over re torqued oil changed.
So maybe the rings are seating themselves.
I have yet to take the carbs off and check float bowl height been busy with work and getting ready to go to europe to visit the Ladys Family
but I will for sure do it when I get back.

Bike runs great though and I have no complaints pulls hard sounds great.
Starts up first kick 90% of the time
the other 10% two kicks.
Pamco and HHB PMA are just F*cking amazing

Click to expand...

The Clymer book calls for a .031 in/.8 mm max for the 70-77 engines. the 78 up get a .040 in/1mm max. My 70-74 factory book calls for the .8 mm spec. His gap is in spec but that doesn't mean it won't use oil.
In the owners manual for a 74 Caddie said it could use 1 quart of oil every 800 miles before oil usage was a problem.
Being a fresh top end it could be more likely too gentle a break in. It is very important to do some very firm roll ons during the first 50 miles of running. Get it up to around 35-40 mph, a good firm roll on up to around 50-55 mph, then let it coast back down to the starting speed, repeat as many times as you can stand then do it a few more times. This hard acceleration and coast down seat the rings in. Once you do this then ride easy for the next few hundred miles then ride it as normal.
If you think it was a too easy break in, you can try XSJohns fix. Put a couple tablespoonfuls of baking soda in each cylinder, pour it in each plug hole, spin the engine to spread the baking soda around and blow out any extra. Now put the plugs in and ride it.
The baking soda is a mild abrasive and can grind out any glazing.
Leo

I just clicked on that link to the honing info. Very interesting reading.
On my next engine I might try it and see if it works.
Leo

XSLeo said:

Put a couple tablespoonfuls of baking soda in each cylinder, pour it in each plug hole, spin the engine to spread the baking soda around and blow out any extra. Now put the plugs in and ride it.
The baking soda is a mild abrasive and can grind out any glazing.
Leo

Click to expand...

Do you have personal experience with this? I ask because I know someone who ruined their motor doing this... but I have also heard of people using it with great success. A few tablespoons sounds like a LOT... but I don't really know. I'm just looking for more specifics because I would consider trying this technique if someone with first hand experience gave me specific directions.

I know a lot of big diesel construction vehicles require a 'de-glazing' powder to be used pretty often. They just holed the container of powder in front of the intake, with the filter removed, and let the motor suck it in. I think its pretty cool... but the type and amount of powder you use makes the difference between de-glazing and ruining a motor.

XSLeo said:

The Clymer book calls for a .031 in/.8 mm max for the 70-77 engines. the 78 up get a .040 in/1mm max. My 70-74 factory book calls for the .8 mm spec. His gap is in spec but that doesn't mean it won't use oil.

Click to expand...

That same 70-74 factory book calls for standard gap of .2-.4 mm (.008" - .016") for the top 2 rings. Running at wear limit on a fresh rebuild is not good practice.

An interesting thread: http://www.xs650.com/forum/showthread.php?t=27477

XSLeo said:

The Clymer book calls for a .031 in/.8 mm max for the 70-77 engines. the 78 up get a .040 in/1mm max. My 70-74 factory book calls for the .8 mm spec. His gap is in spec but that doesn't mean it won't use oil.
In the owners manual for a 74 Caddie said it could use 1 quart of oil every 800 miles before oil usage was a problem.
Being a fresh top end it could be more likely too gentle a break in. It is very important to do some very firm roll ons during the first 50 miles of running. Get it up to around 35-40 mph, a good firm roll on up to around 50-55 mph, then let it coast back down to the starting speed, repeat as many times as you can stand then do it a few more times. This hard acceleration and coast down seat the rings in. Once you do this then ride easy for the next few hundred miles then ride it as normal.
If you think it was a too easy break in, you can try XSJohns fix. Put a couple tablespoonfuls of baking soda in each cylinder, pour it in each plug hole, spin the engine to spread the baking soda around and blow out any extra. Now put the plugs in and ride it.
The baking soda is a mild abrasive and can grind out any glazing.
Leo

Click to expand...

I thought I'd get flamed bad if I suggested this old trick. Back in the sixties we did this a lot on old cars to reseat worn rings. We used a fast idle and sprinkled any number of mild abrasives down the carb. Bon Ami was a favorite, but baking soda was tried first, followed by more serious stuff if that didn't prove to be enough. Ajax, Comet, etc. Mind you we weren't worried about ruining a worn out motor, but it was a pretty good success rate. I can't believe someone else would think of it after all these years!

weaselbeak said:

Back in the sixties we did this a lot on old cars to reseat worn rings. We used a fast idle and sprinkled any number of mild abrasives down the carb.

Click to expand...

First I've heard of that trick, but that reminds me of when I was a kid, back in the 50's, I saw this large/thick cloud of white smoke slowly moving down the road. As it got closer, you could just make-out an an old Buick inside that cloud. My father remarked: "He just had a Bardahl treatment". (Thick/pasty ring/cylinder treatment poured down the carburetor).

The reason BonAmi was used was because it contains feldspar instead of vulcanic glass. Vulcanic glass is far too abrasive and will too deeply scratch the cylinder and ring faces. Feldspar is actually used to polish glass. The goal is to mate the ring faces to the inside of the cylinder, not remove material. DON'T use any abrasive that contains vulcanic glass (Comet, Ajax, etc.) I think Bar Keepers Friend also contains feldspar, but I'm not sure. This trick is still used to seat stuborn rings, like chrome faced.

Have I personally tried the baking soda? No, but I have a lot of faith in the things XSJohn had to say.
I agree that a max ring gap on any engine is not the best thing to use.
I would have gotten the cylinders bored out for the next over size or at least the next over rings and fitted them to minimum specs.
Leo