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Discussion Starter · #1 ·
My GT has been a little hard starting lately, often timing out on the first try and the other day it even did so after two tries. I'm no mechanic, but I thought I'd take a look at the plugs since I've always heard they're a good indicator of engine health. I've got about 6200 miles on the bike, and am running the stock ECU. No FatDuc 02 manipulator (although I plan to get one) - just have the stock setup with the evap canister removed.

Three plugs were all quite light in color (off-white), while the fourth - the one on the left of the front cylinder as you're sitting on the bike - was mostly medium brown with about 1/4 of the insulator and the area of the electrode above it the same light color as the other three plugs.

I know the bike runs lean with the stock setup, so I'm guessing this would account for the light color of three of the plugs. What I'm wondering is:

1) Could the color difference between the two plugs in the front cylinder be due to a difference in their gap I don't have a tool, but just by eyeballing I could tell the lighter color plug had a slightly larger gap. If not the gap, what would account for the color discrepancy between two plugs in the same cylinder? I didn't look at all four plugs at the same time to compare all their gaps.

2) Is there any reason to rotate your plugs to different positions and\or different cylinders?

3) Is it normal for the plugs of a bike with the stock setup to look lighter than the classic golden-brown I was told is the ideal color?

4) Finally, I realize a number of things could account for the harder starting, but are there one or two most likely causes?

Thanks in advance for any input.
 

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I know the bike runs lean with the stock setup, so I'm guessing this would account for the light color of three of the plugs.
No, it's not just the lean mixture, although that's part of it. Modern unleaded gasolines just don't throw nearly as much color as in the old days.

1) Could the color difference between the two plugs in the front cylinder be due to a difference in their gap I don't have a tool, but just by eyeballing I could tell the lighter color plug had a slightly larger gap.
No. The color of the sparkplug is an indicator of mixture and plug heat-range. The tip of the plug stays the same heat whether the spark is firing or not.

If not the gap, what would account for the color discrepancy between two plugs in the same cylinder? I didn't look at all four plugs at the same time to compare all their gaps.
Are you saying you didn't look at the color either at the same time? That would make this a complete non-issue.

2) Is there any reason to rotate your plugs to different positions and\or different cylinders?
No.

3) Is it normal for the plugs of a bike with the stock setup to look lighter than the classic golden-brown I was told is the ideal color?
Yes

4) Finally, I realize a number of things could account for the harder starting, but are there one or two most likely causes?
Failed/failing temperature sensor or failing fuel pump hose clamp would be my first two guesses.
 

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Hard starting can be caused by all kinds of tuning issues, valve adjustment, worn valve guides, low battery voltage, etc. I know mine starts much easier when I keep it on a battery tender. Sometimes it gets a bit hard to start when it's cold out, but if it otherwise has been running great I just crack the throttle a couple times while it's cranking and that usually does the trick.
 

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Discussion Starter · #4 ·
Are you saying you didn't look at the color either at the same time? That would make this a complete non-issue.
Major - thanks for the info. Let me clarify too about the above quote. I did check all 4 plugs at the same time by starting on the left (kickstand) side, then the right. However, I only compared the gaps between the two plugs on the left side.

dietrich - thanks as well for the info re the hard starting. It'll probably be due for the 7500 mile maintenance in 6-8 weeks so the dealer can check the things you mentioned then. The starting issue hasn't gotten to the point where I feel reluctant to ride it to work for fear of it not starting for the ride home, and hopefully it won't get that way before I take it in for the maintenance. In the meantime I'll try the throttle crack when it's being stubborn.
 
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