Idle circuit plug chop

[dailydrifter]

I'm trying to dial in my idle so I did a plug chop. Installed fresh plugs into the warmed up engine, let idle for ten minutes then shut it down.

 

 

And from the other side of the same porcelain

 

 

I'm now running k&n pods DMC 916 exhaust, vf4 , stock carbs without tors, 30 pilot 290 main and needle in the 4th position from bottom, 2.5 turns out on air screws 800ft elevation 68*

 

I thought a 30 pilot would put me on the rich side but looking at the chop I would say it looks lean right? Also only one side of the porcelain has color and I'm not sure why that is. Any help would really be appreciated. Thanks

[dailydrifter]

Also it kicks over easier then when I was running 27.5 pilots. Usually 1st or second kick

[dave5.0]

Interesting. Do people actually do plug chops on pilot circuit? I just tweak the screws till I get the highest idle. And or change the jet till I'm in range with turns out and then get the highest idle. I'd think doing a plug chop would be a waste of plugs. Wait and see what somebody smarter than me says.

[dailydrifter]

Most people probably wouldn't but I tried adjusting the air screw for highest idle and I can't notice a difference either way so I decided a plug chop would take the guess work out of the idle air mixture

[dailydrifter]

Now 2 turns out on air screw and 12 minutes of idle

[trickedcarbine]

Stop.

 

Any knowledge you have of jetting needs to be put in the trash can. There is no way you can do a plug chop like that to determine a pilot jet. You are spending money that doesn't need spending. Idling a bike longer then it should with no airflow over the radiator. And wasting time doing things that make no sense.

 

Leave the 30 in there.

[dave5.0]

I think with the VF4s you might run a little richer on the pilot. Not from experience just what I've read. With no more than you have going on you should be pretty close with that 30. You should be able to notice a difference adjusting your Air fuel screws. You'll probably end up chopping plugs all day and wasting $50 worth of plugs. If you can't get it with the 30 try the next size up and see if the fuel screws make a difference. If you aren't ported or anything though I can't imagine you would be too much more than that.

[dailydrifter]

I was following the direction of this link http://www.dfn.com/agservices/jetfaq.html and it specifically states that a plug chop for the idle circuit can be done and I followed it to the letter. Since I cannot hear a difference in idle speed while adjusting the air screw (keep in mind my hearing is not the greatest) I need another way to verify where its at. That's why I tried the plug chop. Is there a reason why theres no way to plug chop the idle circuit? Is there a better way to go about this?

[sprinklerman]

If it idles good, that's all you need an idle circuit to do.

Yes, all the circuits are cumulative, but the idle circuit really just needs to idle. Very little measurable impact on the rest of the jetting in the grand scheme of things.

[dailydrifter]

OK I will leave it where it is at then. Thank you for the replies

[trickedcarbine]

I was following the direction of this link http://www.dfn.com/agservices/jetfaq.html and it specifically states that a plug chop for the idle circuit can be done and I followed it to the letter.

Copied and pasted from that link:

"To verify your pilot/airscrew circuit jetting, start the motor and let it warm up fully; install fresh spark plugs, start it (without using the choke) and let the motor idle for about 10 minutes; pull the plugs and look at the center electrode and base ring; they should be a light chocolate brown color if you're dialed in."

That is not a plug chop. There's a little over interpretation going on......

[dailydrifter]

I see where I went wrong now. I thought the base ring was the ring on the porcelain but its actually the ring at the end of the plug closest to the piston at the end of the threaded portion. However I'm now confused because if you look at the first pic I posted the base ring has no color at all. It seems to run fine though so I'll stop beating the subject to death

[dave5.0]

I'd say your fine. If you spend that much time dialing in the mid and upper range that thing should run pretty good. I've never spent a lot of time messing with the idle circuit. If it's not close you can get a bog off idle and other crap like that. But if you don't have that goin on move on. Set it up so it revs clean of idle and head to the needle.