sert data tuning help please
#21
08-16-2007, 07:49 PM
RE: sert data tuning help please
No. The length of the insulator/center electrode is what determines a plug's heat range. Too short and it sinks heat too quickly, too long, not quickly enough.
The ground electrode should be the same on both the coldest and hottest plugs in the range.
The color change on the ground electrode is indicative of the timing. There is one which should be over the center electrode indicating the idle timing and the other should be up into the radius for the overall timing. Too close to the base of the plug and it's too advanced.
I'm not disputing some of the other stuff you listed.
The ground electrode should be the same on both the coldest and hottest plugs in the range.
The color change on the ground electrode is indicative of the timing. There is one which should be over the center electrode indicating the idle timing and the other should be up into the radius for the overall timing. Too close to the base of the plug and it's too advanced.
I'm not disputing some of the other stuff you listed.
#22
08-17-2007, 06:06 AM
RE: sert data tuning help please
Thanks I will check that out next time I get on the bike to see if it accelerates when letting off.
ORIGINAL: glens
I just looked at the plugs pictures from that other post. Did you use those plugs much before the most recent tune? If so, you really should get fresh ones so you can see what's happening now without having to sort through all the other stuff.
The idle timing looks right, the total timing looks to be a bit too advanced. There's no way to see in the photos if the mixture is right or, really, whether the heat range is correct. For the mixture you look for a soot ring right at the base of the insulator down inside. You don't want much more than a millimeter-thick ring. To determine whether the heat range is correct you note the difference in the appearance of the insulator from top to bottom. Going by just the threads can be deceiving. The plugs don't look too bad, really.
You say it's a little hesitant above 4 grand. What's the initial response when you close the throttle while there? You can tell rich from lean by doing that. If you're lean it will actually feel like it'll accelerate for a split second as you close the throttle.
I just looked at the plugs pictures from that other post. Did you use those plugs much before the most recent tune? If so, you really should get fresh ones so you can see what's happening now without having to sort through all the other stuff.
The idle timing looks right, the total timing looks to be a bit too advanced. There's no way to see in the photos if the mixture is right or, really, whether the heat range is correct. For the mixture you look for a soot ring right at the base of the insulator down inside. You don't want much more than a millimeter-thick ring. To determine whether the heat range is correct you note the difference in the appearance of the insulator from top to bottom. Going by just the threads can be deceiving. The plugs don't look too bad, really.
You say it's a little hesitant above 4 grand. What's the initial response when you close the throttle while there? You can tell rich from lean by doing that. If you're lean it will actually feel like it'll accelerate for a split second as you close the throttle.
#23
08-17-2007, 06:11 AM
RE: sert data tuning help please
ORIGINAL: glens
No. The length of the insulator/center electrode is what determines a plug's heat range. Too short and it sinks heat too quickly, too long, not quickly enough.
The ground electrode should be the same on both the coldest and hottest plugs in the range.
The color change on the ground electrode is indicative of the timing. There is one which should be over the center electrode indicating the idle timing and the other should be up into the radius for the overall timing. Too close to the base of the plug and it's too advanced.
I'm not disputing some of the other stuff you listed.
No. The length of the insulator/center electrode is what determines a plug's heat range. Too short and it sinks heat too quickly, too long, not quickly enough.
The ground electrode should be the same on both the coldest and hottest plugs in the range.
The color change on the ground electrode is indicative of the timing. There is one which should be over the center electrode indicating the idle timing and the other should be up into the radius for the overall timing. Too close to the base of the plug and it's too advanced.
I'm not disputing some of the other stuff you listed.
The ground electrode should be the same on both the coldest and hottest plugs in the range.
I was replying to your statement above
To determine whether the heat range is correct you note the difference in the appearance of the insulator from top to bottom
and
The color change on the ground electrode is indicative of the timing
and
The color change on the ground electrode is indicative of the timing
No. The length of the insulator/center electrode is what determines a plug's heat range. Too short and it sinks heat too quickly, too long, not quickly enough.
You also made a statement as follows
You say it's a little hesitant above 4 grand. What's the initial response when you close the throttle while there? You can tell rich from lean by doing that. If you're lean it will actually feel like it'll accelerate for a split second as you close the throttle.
#25
08-17-2007, 12:23 PM
RE: sert data tuning help please
That was too easy a way out.
The ground electrode is heat-sunk to the threaded portion of the plug base, thus directly to the cylinder head. Everything else being right it will behave no differently with a short positive electrode that's sooty or with a long one that's blistered. The heat range of the plug is only to control the operational conditions of the positive electrode. Unless the plug is way out of range or there are combustion problems caused by that or other anomalies, the ground strap will behave and appear very consistently across heat ranges.
Lean down your (yes, it's very fast-acting) FI system, pour on the gas, then let off the throttle and see if you still don't detect the results of lingering fuel being combined with reduced air.
The ground electrode is heat-sunk to the threaded portion of the plug base, thus directly to the cylinder head. Everything else being right it will behave no differently with a short positive electrode that's sooty or with a long one that's blistered. The heat range of the plug is only to control the operational conditions of the positive electrode. Unless the plug is way out of range or there are combustion problems caused by that or other anomalies, the ground strap will behave and appear very consistently across heat ranges.
Lean down your (yes, it's very fast-acting) FI system, pour on the gas, then let off the throttle and see if you still don't detect the results of lingering fuel being combined with reduced air.
#26
08-17-2007, 04:01 PM
RE: sert data tuning help please
The ground electrode is heat-sunk to the threaded portion of the plug base, thus directly to the cylinder head. Everything else being right it will behave no differently with a short positive electrode that's sooty or with a long one that's blistered. The heat range of the plug is only to control the operational conditions of the positive electrode
I disagree.
Everything else being right it will behave no differently with a short positive electrode that's sooty or with a long one that's blistered.
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#27
08-18-2007, 09:31 AM
RE: sert data tuning help please
The porcelain is the insulator on the positive electrode and it was that insulator to which I was referring. I apologize for giving you the impression I'd thought the electrode itself would "blister".
What do you disagree with? That the negative electrode is heat-sunk directly to the cylinder head or that the heat range of the plug is to control the conditions of the positive electrode? They're both true statements.
What do you disagree with? That the negative electrode is heat-sunk directly to the cylinder head or that the heat range of the plug is to control the conditions of the positive electrode? They're both true statements.
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