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Old Jul 31, 2009 | 03:07 PM
  #11  
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The 93 octane may contribute to the carbon build up. There is no benefit to running a higher octane than needed if it runs good on 89 then run that. Running a higher octane than needed will result in am incomplete burn leading to carbon build up.
 
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Old Jul 31, 2009 | 04:03 PM
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I beleive the SE plugs were pulled because Splitfire quit making the plug and I heard a 110" engine swallowed some pieces of the SE plugs. Can you go a tad leaner on your mix?
 
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Old Jul 31, 2009 | 04:43 PM
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I was under the impression to always use 93 and the reason was for better combustion. I'd like to hear more about this.

This was the plugs & pistons from my 96" SE Stg 1 map. I have a PC V on my 103 build, so yes I can adjust it after I monitor a new set of plugs. The map is pretty rich from Fuel Moto.

I'm still concerned about the build-up and whether I should use mystery oil religiously and/or try 89/91 octane (and avoid quicky marts).

Thanks for all the replies guys.
 
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Old Jul 31, 2009 | 05:11 PM
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The higher the octane rating the greater the fuels resistance to combustion.
High octane fuels were develop for use in high compression engines.The only way I can see you getting that type of carbon build up is from unburnt fuel.
It would be a good idea to have have the AFR on your 103 checked rather than trying to tune it by reading the plugs.

By the way how was the fuel economy on your stage 1 96?
 
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Old Jul 31, 2009 | 05:45 PM
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I've got about 300 miles to go then I'll hit the dyno and check afr.
My mileage on the 96 was 40+ but not positive exactly. I could go 200 mi before needing gas (running hard usually).

If I try lower octane will pinging and detonation be REAL obvious?
The bike is pretty freaking loud now with the 103 & V&H.
 
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Old Jul 31, 2009 | 06:07 PM
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Looks like you have a combination of issues going on here. The octane of fuel, your spark plug gaps being too wide, you hard the bike hard, perhaps your AFR. What type of air cleaner are you running? You may need more volume of air. I see you have other tha OEM plug wires, do you have different coil or the factory one? The pretty colored wired do almost nothing to boost your spark without a advanced after market coil. So a good coil may also help
 
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Old Jul 31, 2009 | 06:22 PM
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13:1 across the board is a rich mixture and will carbon up like that. No reason to be at 13:1 on a light load cruise. Lean it into 13.8:1 to 14:1 in the regular cruise ranges 1000 through 3000 rpms MAP kpa 30 through 75-80 and you will have less carbon build up, better fuel efficiency and a cleaner running bike. Leave the rich 12.5:1-13.5:1 ratios for the heavy loads, full throttle and high rpms.
 
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Old Aug 1, 2009 | 04:36 PM
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I have the S&S air cleaner which flows mega air (is too much a bad thing?)
and the wires are SE. Yeah, I've read that they can cause issues so I may go back to OEM. No cure for the riding hard part.

man4mopar - you had me till here "MAP kpa 30 through 75-80" can you translate for dummies?

The 103 is hauling *** but has decel popping with throttle roll-off after getting on it. My V&H pipes probably don't help that but I preferred their sound over the 2>1's. I've been going between FuelMoto and Dynojet maps to pick one before dynoing. I don't want my 103 looking like the 96. I see a tune in my future if I can ever find somebody worthy.
 
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Old Aug 1, 2009 | 05:19 PM
  #19  
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[quote=pelliott6;5359278]I

man4mopar - you had me till here "MAP kpa 30 through 75-80" can you translate for dummies?

quote]

Fuel mapping for the delphie system is AFR for a given rpm at what MAP(manifold absolute pressure) in kpa. The higher the load or wide open take offs will have a higher MAP kpa.

Alpha N systems like T-max and DTT TCFI's use TPS % at RPMs. Those it is ideal to be 13.8:1-14.1:1 in the 0%-40% ranges. If your hard on it you will be past 40% thorttle and the richer mixture can help.

Hope that helps out.

Oh and for the air cleaner flowing too much, theres no such thing. Unless of course your cylinder pressures get too high and blow something off like a head. Which unless you are running forced air of some sort you should have no worries.
 
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Old Aug 1, 2009 | 05:31 PM
  #20  
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does your bike use any oil? I've always wondered how much carbon buildup can be attributed to the head breathers routing oil mist into the intake to be reburned in the engine.
 
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