spark plugs 9 vs 8

[konarider94]

So i recently put in new spark plugs. I went with the DCPR9EIX plugs against my better judgement. I know its one heat range colder than stock but so many people on here swear by them. Well it runs like garbage now I was much happier with the factory heat range. I will be switching back to my buell performance plugs and will be getting the 8 heat range after these wear out.

 

[snrusnak]

you're the first I've ever heard say they ran worse. Did you gap them?

 

[konarider94]

yes and i gapped them with the correct tool. not that crappy disc kind.

 

[snrusnak]

ok was going to say maybe you broke the iridium tip but sounds like you know what you're doing.

Where do you live? (what temperature?)

 

[konarider94]

Michigan. Its been in the 40's in the morning and 60's in the afternoon

 

[konarider94]

My thoughts are the plugs suck which i can verify by putting my old ones back in. Otherwise maybe i damaged a spark plug wire.

 

[nazark_18]

Michigan. Its been in the 40's in the morning and 60's in the afternoon

Where in Michigan. I live in Muskegon. 40 min North of GR.

 

[konarider94]

kzoo, brandon(xtremelow) lives in muskegon too, although he doesnt have buells anymore

 

[nazark_18]

Do you live in the apt. by KCHS?

 

[snrusnak]

you're climate might have to do with it.

 

[konarider94]

you're climate might have to do with it.

doubtful. ambient conditions have little effect on the combustion quality. the tip of the plug is cooler on the 9 than the 8. the theory behind it is that the tip of the 8 is getting too hot causing pre-ignition which is what causes the engine to get hot. the spark plug directly does not change the engine temperature. the colder plug will resist pre-ignition better. i had heard some top end noise i thought could have been attributed to pre-ignition but i didnt really think it was. i figured id give the colder plug a try because of happy results across the forum. im pretty convinced now that it is not necessary.

i do still plan on looking into my plug wires though.

 

[konarider94]

you dont need a colder plug unless you have a pre-ignition problem. what doesnt make sense is one step colder shouldnt run this poor right away, usually it will take time for the plug to develop deposits if its too cold. i will investigate the plugs and the wires and post up results if i figure something out. i posted this a little too hastily before i really thought about what was happening.

 

[snrusnak]

I understand the difference in design with the heat ranges. You are right the heat range of the plug doesn't much effect the operating temperature of the bike but if the plug isn't getting hot enough(engine in cold climate, takes long time to warm up, or doesn't warm up to the same temp as in a warm climate) the plug may be too cold for your ambient temperature. I think you'd agree the operating temperature of the engine in 40degF vs 100degF would vary somewhat(probably greatly).

 

[buellbradski]

huh ? [confused] mine ran like a bag of crap with 8's and it runs great with 9"s even in 40-60degree weather.different tune maybe?

 

[snrusnak]

Surely there's some variation between every bike, rider, conditions, etc.

I just know my bike when stock ran way to hot and lean, and the race maps and colder plugs were NEEDED, in my case. My bike was nearly unridable before. I regretted buying it until I did these few easy/cheap mods and then realized how much I loved the bike. I typically ride in 90-105 deg F weather though. Sometimes in traffic.

 

[konarider94]

update on the situation. went back to my old plugs and it ran great again. classic case of me needing to learn to leave **** alone. anyway the "old" plug is a buell pro-series performace plug with ~6-7k miles on it. the one on the right is the new DCPR9EIX with about 60 or 70 miles.

 

[snrusnak]

That NGK iridium plug on the right appears to be missing it's center electrode...

 

[konarider94]

i assure you it is not missing....this would be a good time for the super macro picture

 

[snrusnak]

maybe another picture for proof

It is odd that it ran so poorly. Almost looks as if it wasn't even sparking with all the black carbon buildup.

 

[konarider94]

i will with my camera when i get home. this was a quick cell phone pic but im in ottawa,on until tomorrow.