Which spark plugs
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Road Master
Joined: Dec 2006
Posts: 1,200
Likes: 3
From: Simpsonville, SC
Which spark plugs
I have a 95" with about 10.5:1, and carbed. I have an adjustable timing curve on my ignition and have a very tame curve but still get a slight ping when there is a load on it. I wonder if changing plugs would help. Would I want a colder or hotter plug? Any recommendations? What about gap? Narrow or wide?
K. I run nitrous in my mustang. We use copper plugs because those precious metal plugs(iridium,platinum) get hot and will cause pre-combustion which would blow the engine up when spraying. I think a hotter plug will also cause the same issue.
Maybe 1 heat range colder. Plugs are cheap. Give er a shot.
Now I will probably get flamed but whatever. Acetone mixed in a ratio of 2 ounces per 5 gallons of fuel will reduce the surface tension of the fuel. Allowing for a more complete burn. And at such a low concentration it does not harm anything as far as fuel lines,pump,gaskets etc. I added acetone for the first time at the track. An old racer who has been spraying nitrous for 20 years told me to try it. He said it prevents detonation. So when I looked into it I found a wealth of into on the net.
I now use it in every gas motor I own. Along with 1 ounce of low ash 2 stroke oil per 5
gallons of fuel. Every single motor from my air compressors to generators to all 4 of our vehicles and 3 bikes have all seen a decrease in consumption. Your results may vary
Maybe 1 heat range colder. Plugs are cheap. Give er a shot.
Now I will probably get flamed but whatever. Acetone mixed in a ratio of 2 ounces per 5 gallons of fuel will reduce the surface tension of the fuel. Allowing for a more complete burn. And at such a low concentration it does not harm anything as far as fuel lines,pump,gaskets etc. I added acetone for the first time at the track. An old racer who has been spraying nitrous for 20 years told me to try it. He said it prevents detonation. So when I looked into it I found a wealth of into on the net.
I now use it in every gas motor I own. Along with 1 ounce of low ash 2 stroke oil per 5
gallons of fuel. Every single motor from my air compressors to generators to all 4 of our vehicles and 3 bikes have all seen a decrease in consumption. Your results may vary
Grand HDF Member
Joined: Jan 2012
Posts: 4,445
Likes: 2,822
From: Oklahoma
My understanding of spark plug heat range deals more with controlling deposits on the plugs, rather than controlling pre-ignition. Check your current plugs and look for evidence of overheating, blistering, and color appropriate to plugs running too hot. If they have much in the way of deposits on them, they might even be too cool for the way you drive. A "hotter" plug doesn't bleed off the heat from combustion into the surrounding metal so it keps the tip area hotter. A "cooler" plug bleeds off the heat faster so the tip runs cooler. Retaining just enough heat so the scavenging agents in the gas will keep the plugs clean is the ideal heat range. You can try a cooler plug if you wish, if it is too cool, it will foul quickly. A few hundred miles to perhaps 1500 miles and you will get increasing missing. Too hot a plug can cause real damage, but so too can pinging/knocking.
Pinging, pre-ignition, knocking or whatever folks want to call it is more a factor of the octane of the gas you are burning.
Is your "mild" advance more aggressive than the factory advance curve? If so, you may just be too far advanced and retarding the spark a bit more will fix the problem. Perhaps you should be downshifting when you feed in as much throttle as when this happens. Have no idea how you manage your gears/throttle coordination.
Pinging, pre-ignition, knocking or whatever folks want to call it is more a factor of the octane of the gas you are burning.
Is your "mild" advance more aggressive than the factory advance curve? If so, you may just be too far advanced and retarding the spark a bit more will fix the problem. Perhaps you should be downshifting when you feed in as much throttle as when this happens. Have no idea how you manage your gears/throttle coordination.
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Road Master
Joined: Dec 2006
Posts: 1,200
Likes: 3
From: Simpsonville, SC
Is your "mild" advance more aggressive than the factory advance curve? If so, you may just be too far advanced and retarding the spark a bit more will fix the problem. Perhaps you should be downshifting when you feed in as much throttle as when this happens. Have no idea how you manage your gears/throttle coordination.[/QUOTE]
When I called Dyna about the pinging and ignition module, they said that I was running very conservative. I tried richening it with bigger jets but that didn't really make a difference. I'm gonna try a colder plug and see if it helps, unless some other suggestions.
When I called Dyna about the pinging and ignition module, they said that I was running very conservative. I tried richening it with bigger jets but that didn't really make a difference. I'm gonna try a colder plug and see if it helps, unless some other suggestions.
Grand HDF Member
Joined: Jan 2012
Posts: 4,445
Likes: 2,822
From: Oklahoma
Hope the plug change works for you. If not, I'm thinking the stock engine already requires premium fuel and your compression ratio is higher (I guess). What is the highest octane fuel you can get? Perhaps some octane booster might help, though I have no personal experience with it. Any chance you might have some sort of exhaust restriction?
Stage III
Joined: Jun 2012
Posts: 3
Likes: 0
From: SW, NM
hmmm, i recently installed iridium plugs on my stock 'o6 softail, tc/88-b, live in a very hot climate(SW, NM) I typically use 91 octane. No pinging but I'm getting shitty gas mileage, ( don't ask exactly what i'm getting, i just know when mileage between tanks is low.) Should I return to stock type plugs? I also climb to high altitudes in Colorado (over 10K'). Any experienced riders comments would be greatly appreciated. Be safe y'all.
WFO 1955
WFO 1955
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Ultimate HDF Member
Joined: Jul 2006
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From: Nashville, TN
My Sporty is running 10.5:1 compression, with some other engine enhancements. It's a carbed bike, and the Champion plugs work just fine.
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Joined: Aug 2011
Posts: 68
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From: St Charles, IL
Having a similar issue with my 01 RKC. It has the motor built but by a previous owner so still digging and finding out what all was done. Running a HSR 45 carb and Rienhart Duals. What did Dyna recommend to you for the advance setting? I have been playing with jets to try to also get rid of the pinging.
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