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Discussion Starter #1
Pulled the plug and here it is -> What do you folks think? Have not checked the mixture screw position yet. I live at 1753 metres (6,000 feet) above sea level - apparently ;)
20150815_120733.jpg 20150815_120745.jpg 20150815_120805.jpg 20150815_120824.jpg

Thanks
 

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If I looked at only the first pic I'd say it was normal.....if I looked at only the last pic I'd say it was too lean.:confused: I'll bet you used flash......therefore I can't tell anything about your plug color. Idle mix screw (pilot jet screw) will only affect your plug color after extended idling. The only way to get a good check of plug color (and main jet suitability) is to get up to 60 or more with wide open throttle for at least 2 minutes, pull in the clutch, kill the engine and brake to a stop. THEN look at the plug. Maybe you did that but you did not say.

If you have a post 2001 stock TW with NO carb work, I can tell you unequivocally that your main jet is not too lean...with a 126 jet at 6,000 feet that would be impossible. You would have to have about a 118 jet in there for it to be too lean at that altitude.
 

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Discussion Starter #7
Hi guys, Thanks for all the feedback.

I took another look at it this evening, and despite the flash in the photos, the images are actually fairly on the money, at least to my humanoid eyes.

To answer some questions... I took the plug out after the bike had been standing for at least a week (depressing I know). I had no idea the plug might 'change' appearance depending on where you are on the 'power band'.

The bike seems to run fine to me. Again, I'm a novice here but the throttle response seems ok once she's warm. No flat spots that I can really notice.

The bike used to live at the coast before I got her. No idea if anyone has ever been inside the carb. I would like to clean it one day when I have the time.

So for now I think I'll wait a bit and see. Put in a brand new plug this evening. Kind of hoping to pull it out in a while and see the nice 'holy grail' tan colour that everywhere is recommended

Thanks again.

Sent from my LG-D855 using Tapatalk
 

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Well, don't put too much reliance on a plug reading, because that will only tell you if you are really rich or really lean. If the bike has good throttle response and top end speed, you are fine. If it tends to miss a little on a long gentle climb in 5th it might be a little rich. If it's really lean, you will have all sorts of other issues like hard starting, poor idle, stalling, no top end speed, etc.

Most likely, coming from sea level, it either has the standard 126 or was re-jetted to 130, in which case it will start to get really rich by 7 to 8,000, whereas a 126 will run fine up to 9,000.....mine does. I only go to a 122 above 10,000, which is rare. (2001 onward carbs) It's actually pretty easy to check the jet size without removing it. Replace the JIS screws with SS Allen bolts while you have the float bowl off.....all future jet changes will be much easier.

No need to pull the carb, just loosen the rubber intake bands, rotate the carb to the right about 25 degrees and take the screws out, look at the jet with a magnifying glass and note the number. DO NOT USE A REGULAR PHILLIPS DRIVER! Be careful not to dislodge the gasket, it should stay on the bowl.

If you don't want to buy a set of JIS drivers go to a shop and have them just start the screws (make sure they have JIS drivers first!)...... once broken loose you can use a Phillips without buggering them, then put the Allens in on re-assembly. Or just pay them to pull the float bowl off and record the number of the main jet and replace using the Allen's you hand them.
 

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If my plug looked like that and my bike ran well and I lived at 6,000 feet, I would be a happy camper:rolleyes:!

best regards, MAC
 

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The answer to your question, Am I running too lean, IMO is NO! Maybe just a tad on the rich side, Dark, if I am seeing correct but I would not change anything as long as the bike is running fine.

I don't know anything about being a mile above sea level so I must pass to those who do but your plug looks OK to me. I just pulled my plug yesterday. Bike has 155 miles on it and I do have a flat spot in the throttle response. I did it the way Rocky suggests and coasted into the garage. My plug is way too light to almost still white so I will turn the pilot screw out another 1/4 turn and do the checks until I see toast color and hope the flat spots disappear.

GaryL
 

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To the OP - your plug is fine (and sticking a new one in there means it won't get any colour for a few hundred miles anyway) - leave it alone

GaryL - you're running dangerously lean - next stop is a hole in the top of your piston (seriously) - check you have the right numbers on that plug (NGK/DR8EA) - if it is correct, you need to tweak the carb

Everyone - what difference to plug colour do you think hitting the kill switch and coasting to a halt going to make ?

Fred - bring it on .......
 

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To the OP - your plug is fine (and sticking a new one in there means it won't get any colour for a few hundred miles anyway) - leave it alone

GaryL - you're running dangerously lean - next stop is a hole in the top of your piston (seriously) - check you have the right numbers on that plug (NGK/DR8EA) - if it is correct, you need to tweak the carb

Everyone - what difference to plug colour do you think hitting the kill switch and coasting to a halt going to make ?

Fred - bring it on .......
I certainly agree that my bike is running too lean and this is not good! You can ask anyone here who has been around the TW for a while, this is the way they come adjusted from the factory and the carb pilot adjustment screw is then plugged with a brass cover so you don't mess with it. I have no idea why they do this but since my bike has just 150 miles on it I could not accurately inspect a brand new plug in a brand new engine until I did get some miles on it. It will be adjusted a few times in the next couple rides to be sure I have it richened to where I feel good.

GaryL
 

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GaryL - figured you were on top of things - mentioned as much for anyone else reading this as anything - sorry mate, (comms fault on my side) :rolleyes: ........
 

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No worries, I'm just a friendly civilian squawking code three as I fly through your airspace, littletommy is the experienced guy with plug chopping.:rolleyes:
 

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Yeah – but LittleTommy is more likely to tell you to dive the boat to 200 fathoms, trim the tanks - and then check the plugs …….
 

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The only way to get a good check of plug color (and main jet suitability) is to get up to 60 or more with wide open throttle for at least 2 minutes, pull in the clutch, kill the engine and brake to a stop. THEN look at the plug.
Originally Posted by Purple


Everyone - what difference to plug colour do you think hitting the kill switch and coasting to a halt going to make ?


The difference for me is I have to ride five miles to US 101 to find along enough stretch of road to go over 60mph for two minutes. Then I have to pull over on the shoulder to pull the plug hoping all the while I don't get run over by a logging truck or get a friendly visit from our CHP or Sheriff:rolleyes:. One of these days I'm gonna do it !


best regards, MAC
 

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The difference for me is I have to ride five miles to US 101 to find along enough stretch of road to go over 60mph for two minutes. ......
The only reason to mention 60 mph is that is the approximate speed WOT in 5th will give on the flat. If you found a moderately steep hill you could wind it out in 4th for 2 minutes without going over redline and get about the same result. The whole point of a WOT cut is so that the plug shows almost completely main jet mixture.....as the carb tuning thread indicates, the first part of tuning a carb is to set the main jet size correctly. Everything else follows after.

Sorry, I can't do anything about logging trucks! :eek:
 
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