Right side pipe bluer than the left...why?

Hey all, hope your bike is coming along good or running titty!!
I was wondering if some of you could chime in on this.Here are some pics of my pipes. Notice the different colors (heat?).I was wondering if maybe the carbs are unbalanced or something is not right. My pipes are different colors and the right side,the bluer side, has more pressure coming out the exhaust than the left side.....why? What kind of checks can I do to identify whats going on. The bike rides seemingly fine and seems to have plenty of power aswell.

Side note: On a previous post , I displayed pics of the right side carb throat with some burn rings in the throat. bcware, you thought it might be from starter fluid. I was wondering if this is all rlated.Any ideas? Any and all info would be appreciated.

You could be running lean on the right side. I would start by doing a plug chop or a few (for different RPM ranges). If you are running lean on the right it could be as simple as doing a thorough carb cleaning to solve the problem.

Yep another way of telling your lean is reading the spark plug...whiter it is the more lean, dark is rich. and tan is just right

As the other have said- lean. Why does it blue? Leaner means hotter- more heat, more blue.

You guys beat me to every question I have an answer for >:|
Thats how I found out I was running lean on one side.

ok so this is what I found after pulling the plugs. 'Blue' side plug looks 'rich'
Left side looks tannish/white? What do you guys think?
Sooooo... what does this tell me and where is the adjustment made? I have a Haynes manual and will read up on tuning but nothing beats experience and first hand knowledge. Thanks guys on any input!
gapped @ .028/0.70mm

The white plug looks too white; too lean. The dark plug looks too dark; too rich. If the pressure is different on both sides you're probably not synched properly.

Synch first, then adjust idle screws.

Normal plugs are a darker tan/lighter brown give or take with no blistering.

Oh, and inspect your head gasket; it looks like there is oil on the white plug.

check the pilot settings, my right side runs a bit leaner than the left, i think due to the way fuel gets to the right carb.

I heard somewhere that the left cylinder intakes first, then the right so the charge going into the left has more fuel than the right. That would make sense. Then again, I could be talking out my ass.

that's probably me!

Okay this is the carbs,left and right.

...these are the plugs,left right

...and these are the headers.

So probably synch carbs and check pilot jets and re clean carbs. What about the needles and/ or floats? Could I have screwed somthing up when I had the carbs apart for cleaning the last two times? Thanks guys for all your help.

My right side also definitely runs leaner than the left. Plugs and valve color confirm this for me.

ok so this video is after Ive heated the bike up for about 10-12 min. She runs better cold than heated up and seems not to want to idle without choke in the first position. Actually she will idle just not rev up smooth or respond to throttle. There is some other stuff going on too and maybe you guys can get something out of listening to her. This is mostly in the second position choke and a little without choke.Let me know what you think. I made a video of her starting up cold but was to lengthy. This video seems to shoe a little run on and hesitation...thought that was more significant. Will make another video of her starting up and heating up proper but this is somewhat lengthy although may be helpful!

Colortune could help too.

Ok, I will try and make some suggestions.

White smoke usually means you're running lean.

Is that exhaust new? Did the exhaust gaskets get replaced if the headers were removed at any point?

Is the gas cap venting? Clean it and all passages thoroughly. This is often overlooked, but it's important.

Is fuel flowing through the petcock freely? A vacuum leak or clogged petcock can slow fuel flow significantly. Try running the bike on prime to test flow characteristics. Prime does not use any vacuum from the engine, but on and reserve do.

Are the carb boots new? You can check for leaks with propane gas by spraying it on/around the carbs. If the revs go up you've probably got a leak.

Is there a gasket behind the carb boots? There should be. When you tighten them against the engine they should be snug, but don't crank them down.

Have you pulled and cleaned the carbs completely? Blow out all air passages with compressed air or, better yet, an air compressor. Make sure all fitting are snug; I had a choke "plug" work its way loose on my bike. I am referring to the plunger-like plugs that the choke rod pulls and pushes on. Clean all of tiny pin holes in the pilot jets and emulsion tubes with a single brass wire from a brush. Make sure it's brass! Often wire wheels/brushes are brass-colored, but they are not brass.

What is your float height set to? The manual values are generally wrong.

Have you observed the float needle opening and closing for any funky behavior? Their action can be adjusted, often this is done unintentionally when adjusting the float height.

The idle screws should be about 3 or 3 and a half turns out from closed for a stock-ish setup. Close them by hand or very slowly with a screw driver. Closing them hard will break them; they are usually made of brass and have fine tips.

If the back-pressure from the exhausts feels very different on each side you can do a ghetto-synch. Turn the synch screw very slowly until each side "feels" the same when you hold your hand up near the muffler outlet. You can't use a manometer to synch anyway until each side is reasonably close.

Inspect the head gasket with a flash light. It's located between some of the fins on the head of the engine. Look for signs of oil.

Any questions?

Thanks bc
Whit smoke is coming out of rightside only

The exhaust has not been touched but both mufflers have leaks on the bottom

The gas cap is intresting bcs I cleaned it before and removed all the rust and such but after I cleaned it, started making a whiney air escaping sound.When I open the cap it seems to release vacuum or pressure? Good call bc

Petcock did leak initially but sem to be working. I will run it on 'pri' to see if this makes a diffrence.

Carb boots are new and do have gaskets. tightened maybe a hair to tight.. maybe

Carbs are clean but not boiled clean. I took them apart and found the right side to be in very good condition. Emulsion tubes and mains is where I made sure ther was no obstructions. Where I had issues is with the drift pin on the float needle I could not get that pin out and did not clean the float needle or the filter that is in there. Also my fear is I may have distorted the float tang on that side where I tried to slightly tap the pin out.I am not sure how to get a measurement on float height. I did see the diagram in the manual but what do you actually use to get accurate (00.00mm.) measures?Needles seem to function fine unless like I said I inadvertenly bent the tang.
I will check the idle screw for sure seems like that could be where I might have issues.

I like ghetto checks and will do a rough ghetto check on the butterflys. There is definitely a difference in pressure coming out of the tail pipes.Do I loosen the crew or tighten? Just asking and do I lubricate anything on the mechanism for the butterfly valves?
Sadly the head gasket does have some moisture appearing all around. Very slight but definit moisture. The bike had sat for 28+ years. makes sense the head gasket would leak after sitting for so long then coming back under use.
Thanks bc

Leaks in the mufflers? Like holes? If you have holes they need to be sealed with some kind of muffler cement, but it won't look pretty. Holes will cause you to lose back-pressure and thus run leaner.

If the gas cap is making noise it's probably working fine. My 250 ninja blows off occasionally while sitting, even after long periods of time (cold), but I only notice it on my other bikes after they have been run.

What did you do to fix the petcock? You could pull the entire thing from the tank and get a good look at the inlets. You'll need something clean to catch the good gas though. Also inspect the vacuum hose that comes off the petcock and runs to the carb boots. If this hose has a leak you'll lose vacuum and flow will be hindered.

Hand tight is fine on the carb boots, but be modest.

Check out this thread/video for tips on the carbs: http://www.xs400.com/forum/showthread.php?t=6375

Try penetrating oil and heat to remove the float pin. Be careful as I have seen broken perches from trying to force them off.

Off hand I can't remember if you should tighten or loosen the synch screw based on your current pressure differences (the mechanism is also not intuitive when looking at it). The screw only adjusts one side though. You'll be able to tell right away which way you need to turn when you try it while running; the screw is potent and produces large changes in pressure, so move slowly. The bike could suddenly stop running if you turn too far; just back the screw up and restart. If you get way out of whack you can always pull the carbs and eyeball it close enough to get the bike running again.

Your head gasket looks to be leaking. I didn't notice my leak until I pulled the engine. When I exposed the gasket it was clearly leaking into the cylinder and the valve heads had a layer of oil on them. If oil is getting into the combustion chamber and on your plugs it will foul them and cause strange symptoms and problems running.