plug color...

my first ride owning the bike was great, i had new plugs in it. went about 20 miles. took the plugs out and they have a slight white residue on them. its running lean. its about 45-50 degrees out. should i put bigger jets in or should i drive it more. i cleaned the carbs twice before driving.




here is some of the bike. the seat needs to be covered.

 

Have you checked for air leaks in the carb boots? That would make it run lean too.

 

i havent recently checked but they should be on their good. all the plugs look the same. not sure if its just the temperture that is doing it or what. it runs good. its not running dangerously lean.

 

Nice looking bike! Does that seat hurt your butt? lol

 

Critically Lean!
The Mixture is going-off like a Flash-bulb. Hot and fast.
The performance is F-A-S-T.
That's what get's people into trouble.

Try a "Short-cut"
Cut the point off a Golf Tee nice and flat.
Measure 11/32nds from the Bottom and MARK the Tee's shaft there.
Pre-Set ALL four of your Pilot Mix Screws that deep.

If the Bike STILL runs CRITICALLY Lean from this Short-cut Preset.
a) get a ColorTuner
b) Bump the Pilot FUEL Jet up a notch.

(( Make sure that the Passages are clean and you are actually getting Pilot FUEL up from the Bowl.

 

EEEEk! WAY too lean amigo! You NEED to tweak your air/fuel screws out pronto or you WILL burn a piston or two.
Get to work with Rick's guidance straight away!

 

When the Insulator of the Plug is pure white and the Ground Strap ... Clean and Bluish-looking ... the Mixture is so Lean that the Condition is dangerous.

When the Plug is that Clean it means that the Combustion is so complete that the "Burn" is using all the Fuel in a Hot, Clean, Explosion that likely consumes the Oil Sheen needed to LUBE the Hole.

Insufficient Oil Sheen will play havoc on the Rings and after a time; cause the Block to be heated beyond what AIR COOLING can effectively dissipate.
The resulting factor is Cylinder Wall Damage or Seizure.

If the Insulator show signs of Hairline Fractures or Deterioration, ... the "Burn" will reach temperatures that exceed what Air Cooling is capable of handling and liquify the aluminum of the Piston Crown.

IF you cannot adjust the Mixture to provide a less explosive Mixture by Adjusting the Pilot Mixture Screws to provide sufficient "Supplemental Richness" to lower the Explosive nature of the Air~Fuel Mixture ...

ADD a Suitable Top Cylinder Lube to the Fuel until the cause of the LEAN Condition is rectified.

One such product would be:

Marvel Mystery Oil ... added the Fuel Supply.
-Or-
2-Stroke Oil

3 Oz of Oil added to 3 Gal. of Gas would be 75~80:1

 

marvel mystery oil is less lubricative than the fuel you are mixing it in.

2 stroke oil is perfectly acceptable, and even helps stabilize the fuel for long down periods.

 

The carbs are all stock. still have the plugs in them. I did put a different exhaust on

 

got this from our good friend chacal's page, i went to a 116 for my Mac-ish 4-1

 

If they still have the plugs in them then they aren't clean. You can't clean the pilot circuits with the screws in them.

 

If your plugs look like that, OH YES IT IS.

And iwingameover is right. If your carbs still have the mixture cap plugs in them, they're not COMPLETELY clean; especially the PILOT circuit that those screws control.

The pipes very well could have leaned it out; however if you haven't fully cleaned the carbs then you're not going to have much luck tuning the mixtures.

 

Everyone seems to think the best way to Enrich the Mixture for the Lean Condition presented when the Airbox is removed is to concentrate on the size of the Main FUEL Jet and the Placement of the Needle Valve.

The Problem is NOT Fuel.
The Problem IS AIR.

Increasing the Size of the Main FUEL Jet DOES NOT necessarily increase the Quantity of Fuel supplied.

The Problem to be overcome is DELIVERING Main FUEL Supply.

Before any quantity of Main FUEL Jet Supplied Gas can be drawn-up to exit the top of the Emulsion Tube ...
There MUST be A SUFFICIENT SUPPLY of AIR SURROUNDING the Emulsion Tube.
The Main FUEL Jet can be as Big as the Nozzle of a Fire Hose, ... but if there is NO AIR Surrounding the Emulsion Tube, ... The FUEL is just going to sit with little entering the Intake Stream in an atomized state for efficient Combustion.

The NEGATIVE Pressure on the Intake Horn's Atmosphere Port:
a) Prevents AIR from Surrounding the Emulsion Tube.
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b) Creates a Low Pressure Variant in the Atmosphere Chamber, ... thereby causing a condition that Negates the Vacuum within the Diaphragm Piston.
(The lowered pressure makes is difficult for the Diaphragm to collapse.)

In Turn, ... Causing:
a) A Lean Condition because the Diaphragm Needle does NOT rise enough.
(Often combated by shimming the Needle)
b) Insufficient Main AIR Supply:
Causing:
Not enough AIR to be circulated within the Main AIR Passages to assist in SIPHONING the Main FUEL Supplied by whatever sized Main FUEL Jet.

Resulting in:

Lean Mixtures because insufficient FUEL is released to blend with the ENORMOUS amount of Unregulated and SLOW MOVING Intake Air swirling in a Turbulent Vortex at the entrance to the Carbs.

 

He didn't install PODS (eliminate the airbox) all he did was change the pipes. But he also didn't get the carbs truly clean.

Regardless, it is running horribly lean.

 

Idk guys put over 100 miles on it today, ran great. I did put about 3-4oz of two stroke in but the plugs are the same. I need to check the plugs again but I will be takin the carbs apart again to truely clean them.

 

When you get around to Cleaning the Carbs, ...

Inspect EVERY Jet for "Proper Size" ... and ... "Placement"

Somebody might have swapped-out:

The wrong Carbs
The Wrong SIZE Jets
Jet in the wrong PLACE

I need a Magnifying Glass to see the Number etched on the Jet.

Do a TEST to insure that the Diaphragm Pistons are actually RISING in their Bores.
If they get stuck 1/2 Way UP, ... that will make it run Lean, too.

 

How do you test to see if the piston rises.

 

Do a "Clunk Test"

http://xjbikes.com/Forums/viewtopic/t=1 ... +test.html

 

what plugs do you remove to get to the pilot screw. the carbs have a handful of plugs which ones do you take out.

 

The PLUG is hiding THIS Screw



As You can see from this Illustration showing MIKUNI, ... The Mixture Screw is NOT far Below the Plug.

DO NOT let the Drill breach the Plug and Damage the Screw!!!



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