Okay, what's white with brown specs?

My Sparkplugs. :roll:

I did about 2 hours of forum searching and didn't see a word about white speckled insulators.

Now, I understand white is lean....but brown specs? :?:

Also, adjusting the pilot mixture screw only effects the color of the plugs at idle, right?

What if the plugs are lean at 5k rpm? Float height?

Cleaned my carbs today. A lot easier then I thought it would be.
set the pilot mixture screws at 2.5 turns, and the damn thing ran like a champ. great idle, and lots more power then it had.
Did a plug chop, and all the plugs were white with brown specs?

 

it is lean, and yes, the pilots do have an impact at higher RPM, just not a lot.

do you have the stock jets and stock air filter?

 

Carbs aren't truly clean, float heights could also be a factor.

You're probably right in the ballpark tuning-wise, but your fuel isn't "atomizing" into small enough droplets; you've got a tiny orifice still plugged somewhere.

 

Yup, stock jets and stock filter.
4 into 1 exhaust.

 

Not sure why I didn't set/check the float height when I had the carbs pulled?
I guess I didn't do it because I assumed the carbs would take so much longer to clean. Took me about 7 hours straight. I haven't checked the valve shims yet either.

It ran really really good after I cleaned the carbs, and set the pilot screw to 2.5.

A tiny orifice on three of the four carbs?

I actually decided to rip it apart when I realized riding normally was stressful because I was never sure how the bike was going to run that day.

 

Specks on white insulators is generally a pretty bad sign. It's usually an indication that the engine is going quite lean under load, with the resultant high temperature in the cylinder and excess of air causing the bike to start burning the aluminum of the combustion chamber and piston crown.

Mid-band lean is probably related to the jet needle height or profile (too low and/or too thick). A vacuum leak could also cause problems here, by letting in too much air and by messing up the behavior of the CV slides.

Are there any mods on your bike (pods, different exhaust, etc)? What altitude are you at? Do the carbs have stock jets and needles?

 

Only mod is a 4 into 1 exhaust.

Did some plug chops at idle....and 1&2 (from left to right looking towards the front of the bike) and 3 & 4 were a light black/brownish.

I just checked my float heights dry.....and they were way off off that 17.5mm spec?
They were hanging WAY WAY down?

 

You gotta check the float heights with fluid, the other method is only a starting point.

 

I'm not sure what's right..... I read that 6 page float height thread, and it's is confusing.

When the floats are hanging right side up.....should the float needle be being pulled out slightly by the tang??

 

I'd agree with Fitz that you want to measure these with fluid, rather than dry. I'll go further and say that that fluid should be gasoline, because other fluids have different specific gravities and you'll end up with incorrect float height.

I still think the service fuel level test (bike level on center stand, clear tube used to check fuel level with carbs on bike) is the best bet. If you replace your float bowl screws with allen screws, you should then be able to remove a bowl and tweak a tang if needed without removing the rack.

How about the other two questions I asked:

1. What altitude are you at?

2. Do your carbs have stock jetting, or do they have a "jet kit" in them?

Cheers,
Paul

 

I'm in central WI, so normal attitude.
The bike is stock other then the 4 into 1 exhaust. 8O

Okay, I just reset the floats to 17.5mm dry and reset the pilot screws to 2.5 turns.
I had the idle screw a little too far in, was idling at 3k....had to back that out a little too.

I checked the float levels before I reinstalled the carbs, using a jig and the clear tube method. All appear to be within spec.

It's idling and starting really good right now, took it for a spin around the block. Seems to have decent power.......kinda sluggish. chopped the plugs after idling in the garage for 30 seconds. Running pretty damn hot.

All bone white.
The ground electrode looks a little white.......appears to be running extremely hot.
no color, no speckles, no nothing?

 

back the mixture screws out to three and see if you get any color


mn

 

That was my thought too....so I just went and did that.

No color.

After I changed the float height, any color at idle I did have, disappeared.
(3 and 4 were decent colored)

I will say that my floats, set dry were around 13-14mm.....rather then 17.5mm. When I checked with the clear tube....they were all within approx. .5mm.
Seems like that would make a huge difference.

 

Again, the main things for mid-band power will be the needles, not the idle jets. I'm back to the vacuum leak theory.

 

White with Brown Specs means you are running too Lean.
You could burning Piston Wall sheen as Fuel.
This condition needs corrective measures to avoid serious problems.

Examine the Ceramic surrounding the Center Electrode under a magnifying glass.
If the Ceramic shows Hairline fractures or erosion ... Don't run it.
You might be at Combustion Chamber temperatures which will liquify aluminum.

Protect yourself!
If you cannot adjust the Mixtures Screws to provide Supplemental Richness to reduce the Explosive Lean Mixture ...
TAKE PRECAUTIONARY MEASURES !!

Add a Top Cylinder Lubricant to your Fuel.
Enough to slow-down the "Flash-Bulb Type" of Fuel Ignition you have going-on in there at the present.

This is a good time for you to introduce yourself to:
Marvel Mystery Oil.

http://www.marvelmysteryoil.com/index.php/site/faq/



Specific Gravity Test for Float Height Settings.
Blue = Windshield Washer Fluid > (A non-flammable, pleasant smelling, cleaner; requiring little or no ventilation)
Amber = Gasoline. Stinks and goes "Boom"

 

When I was trying to find a vacuum leak on my bike I was spraying carb cleaner all over the boots I couldn't find a leak until I got spray above the mixture screws. The fluid got sucked right in, even filling the space above the screw head. I pulled out the screw and the little rubber o-rings were gone, might be worth a look.

 

I tried to determine if there was an air leak with a propane torch, but I didn't notice any change in RPM.

I've just pulled the carbs completely apart, and re-cleaned everything.
All of the parts are there. Even with the pilot mixture at 3 turns out, no color.

I suppose absolutely bone white is better then specs, right? 8O

Re-checked all jets, and openings. taking a break now.......but will be reassembling soon.

Still wondering if I should return my floats to the 13-14mm setting they were originally?

 

Air leaks that great would be the Intake Manifolds themselves.
Where they fasten to the Head; leaking under Vacuum.
Manifolds split where the Hose Clamp affixes to the Carb Neck
(or missing clamps)

You might want to check the Size of the Jets
Consider using a Bigger Pilot FUEL Jet.

 

"Specks" only occurs when the engine is lean under load. That's where you have the combination of heat from high power combustion and excess air that leads to aluminum burning. At idle, there's not enough heat to burn aluminum, so you just get white, or maybe glazed, insulators.

 

I get it now. Thank you for the info!

I just went through the entire rack again. Cleaned everything.

Reset the float heights again.
When tested with fuel and clear tube......the levels are nearly level with the bowl seam. Back to adjusting them again.
Which way do I have to go? + or - 17.5mm?

My bike has always ran fairly lean.......not sure what to do?