81 XJ650 YICS SMOKING

MY 1981 HAS STARTED SMOKING, IT RAN OK, BUT ALWAYS HAD TO HAVE CHOKE PARTLY ON. PUT CARB KITS IN ALL 4 CARBS. NOW I DON'T NEED THE CHOKE ON, BUT NOW IT DOES NOT HAVE THE POWER IT DID AND IT IS BLOWING BLUE SMOKE OUT THE EXHAUST. WHAT HAPPENED???

 

Not enough info.

"Carb kits" why?

Stock airbox or pod filters?

Stock exhaust or???

Valves in spec?

Carbs cleaned when you installed the "kits?"

Float levels verified using fuel and clear tubing?

Bench sync'ed?

What method did you use to vacuum sync after all the carb work? Did you vac sync with the YICS blocked?

 

EVERYTHING IS STOCK, CLEANED AND SOAKED CARBS BEFORE KITS, I HAVE A BUDDY THAT HAS A MANOMETER TO SINC THE CARBS AS IT RAN, I PUT THE KITS IN BECAUSE I HAD TO HAVE THE CHOSE SLIGHTLY ON SO IT WOULD RUN GOOD. IT RAN GREAT BEFORE THE KITS OTHER THAN HAVING THE CHOKE ON. DOES'NT BLUE SMOKE USUALLY MEAN OIL?

 

NO I DID NOT BLOCK THE YICS OFF!!

 

Define "carb kits", I think people are going to get hung up on what you mean vs what you are typing.

If everything is stock, than you should be running the stock fuel jets.

 

NEEDLE AND SEATS AND GASKETS, ORIGINAL JETS.

 

Were the bowl floats set correctly? I don't have a YICS bike so I'm unsure if your buddy's syncing efforts were wasted by not having the ports blocked off.



Do me a favor and hit the caps lock too.

 

Big differance with or without blocking YICS. You need to block it.

 

How would i block the yics, my buddy set the floats he said he adjusted them to where there suppose to be, would that make it blow blue smoke, if the carbs are still not synced.

 

You can get a YICS tool from Len at XJ4Ever. Once you get it in sync then you need to colortune each one also. Blue and or black smoke is burning oil. If you haven't checked your valves then you will want to do that first before setting the carbs. Valves not set correctly can cause some smoke related issues. You do want to properly sync with the YICS tool and do a color tune twice to make sure everything is set corretly but do this after you do the valves.

 

If the bike ran fine except for needing choke all the time, chances are the carbs just needed to be cleaned.

That being said, now that you've messed with the carbs, everything I listed needs to be done, IN ORDER, to get it running right again.

Based on everything you've told us, your blue smoke is more likely due to "dumping" excess fuel than anything else; I suspect the float levels are now way off.

 

I have a x yamaha mechanic for a neighbor(he did not work on bikes much) but he is telling me the blue smoke is oil and that my oil filter or breather are clogged causing oil blow by. could this be true?

 

Check the floats.

 

Anything is possible, although I doubt that diagnosis. But if you rejetted the carbs, they need to be re-sync'ed. You cannot sync if the valves aren't in spec; and you can't adjust mixtures properly if the float levels are off.

There's no quick fix here; you started in on the carbs and now you've got to go the whole monty, it's as simple as that.

 

So you think if i check the valves (witch have never been touched) set the floats and sync the carbs using the yics tool, that it should be good to go?

 

I'd check the valves, then compression.

 

Do those and colortune it also then yes, I think that this may solve your issue.

 

Given the history of this thread, I think you will need to point the OP toward how to do plug chops, seeing as the likely hood of him having a colortune is slim.

 

There's nothing wrong with doing a Compression Test without Checking the Valves first.

The Compression Test is a TEST!

The Test provides answers to what condition the Engine is in.
If a Piston is Holed, ... a Valve Adjustment won't heal it.

The Compression Test is like a Blood Pressure Test.
What's ... going ... on???

Got Low Numbers?
Do it Wet?

No compression. = Priest.
Values increase? = Rings.
No improvement? = Valves.

You ran good with Choke?
Your Bike was starved for Gas.

Did you Punch-Out the Center Tubes and Probe the Air Metering Ports?
I'd guess, ... no.

Clean the Carbs, ... thoroughly!
Check that your AIR Jets aren't reversed.

 

Also make sure the mixture is right. A colour tune plug would help plenty with that.

 

What did you soak the carbs in? Did you replace the shaft seals when you did the kits?

 

I thought you have to rejet when you add kits

 

I have 125lbs is all 4 cylinders, that was the fist thing i did! i drained the oil last night and checked this morning, and i don't see any gas in the oil. i went to our lovely dealer and of course they are not to excited about touching it and tell me it might end up being a lot of hours put in it, at 90 an hour it might get a little spendy just for labor.

 

The most likely cause is the fact that most "carb kits'" float valves aren't exactly the same as stock, requiring the float levels to be readjusted.

However, as stated more than once, now that you've messed with the carbs you've got to put everything "back to square 1" to get it properly adjusted.

VALVES FIRST.

Then, IN ORDER:

-Float levels verified using fuel and clear tubing.

-Bench sync.

---carbs back on bike---

-Running vacuum sync

-Mixture tweaking as needed.

You're going to get nowhere "poking at" it the way you are now.

 

WELL THAT DID NOT GO AS PLANNED, PULLED OFF CARB BOWLS AND ONE OF THE CASTED ARMS HOLDING THE FLOAT PIN SNAPPED OFF. NOW I AM SCREWED!!

 

JB weld it back on, thats what I did and its good as gold

 

WILL JB WELD HOLD IN GAS THOUGH? ANY BODY OUT THERE KNOW IF A 1100 CARBS ARE THE SAME AS A 650?????

 

Yes it will hold. JB weld is good stuff

 

I used the jb weld that comes in a two part stick. JB STIK Its black in the center and a metalic grey on the outside layer. What you do is slice off a piece and knead it together until its a consistant dark grey. The working time on this stuff is probably like 10 mins. once you secured your float arm in the right spot dampen your finger and smooth it out to finish. make sure it doesnt get into any ports, jets or gasket surfaces because once its hard its near impossible to remove from them without damaging the part. Check out the link fro more info or google JB Stik