Plug chop - any suggestions?

[Guest]

Aiight, here's the dirt:

Plugs have a good year or better on them. No vacuum leaks, no issues at all other than the bike just seems weak in the upper rpms. I pulled a good long hill at WOT around 7500-8000 rpm for this plug chop. What would you guys recommend, if anything? Thanks in advance!

20170813_165237.jpg

[mmattockx]

Well, it certainly isn't rich. Since you say it has no power then I would try one size up on the mains and see how it feels.


Mark

[posplayr]

You might want to read the factorypros running guide

http://www.factorypro.com/tech/carbtun.html

before you do anything select the mai . Then before you move on make sure to select the main.

make sure to get the main right !!!

[JJ]

The insulators look just a tad lean to me....

[Ric]

Thanks yall! I'm about to make some more pipes for the bike and maybe swap in a set of 250 cams, so I may be a little extra judicious on that main jet.

I downloaded a guide to reading the color of plugs, and I know black is rich, coffee colored is dead on, gray is lean, and white is too lean. That guide said to read the base ring of the plug, but then this machine has been a little confusing to nail down at best.

[GregT]

Two unknowns - what grade are the plugs, the NGK number please. And what fuel are you running it on ?

What I see in the pic is a typical unleaded, possibly ethanol containing, modern fuel.
The old colour guides are no longer relevant. As long as the center porcelain isn't blistering and you've got the typical modern black outer ring it's pretty close.

[mmattockx]

What I see in the pic is a typical unleaded, possibly ethanol containing, modern fuel.
The old colour guides are no longer relevant. As long as the center porcelain isn't blistering and you've got the typical modern black outer ring it's pretty close.

Great info, thanks. At what point does it start being lean on that ring? Grey? Dark grey? Some other colour?


Mark

[GregT]

Great info, thanks. At what point does it start being lean on that ring? Grey? Dark grey? Some other colour?


Mark

Never seen it lighter than dark grey on the unleaded here in NZ. For some reason, the modern fuels have a very narrow range of carbon colours. The coolest part of the plug - the outer ring - will invariably be dark even if the inner porcelain is dead white.
It's an annoying fact of modern tuning that for absolute best results you now need a dyno and gas analysis...The old days of plug chopping it on a run up the road still get you close but unless you're lucky, not to the optimum.

[mmattockx]

It's an annoying fact of modern tuning that for absolute best results you now need a dyno and gas analysis.

That is an issue for those of us not doing it for anything beyond a hobby on our own bikes.

Thanks for the help,
Mark

[Ric]

Did not know the gas would make a difference like that, thanks a lot!

I just filled up with 89-octane(R+M/2) with ethanol. I can get 100% gas here, as well as where my family and in-laws live. But then I'm torn between tuning for 100% gas for performance, or E-10 for availability. Is there a noticeable difference?

[Ric]

Oh! The plug number is DE8A. I run 7s in the winter.

[GregT]

Did not know the gas would make a difference like that, thanks a lot!

I just filled up with 89-octane(R+M/2) with ethanol. I can get 100% gas here, as well as where my family and in-laws live. But then I'm torn between tuning for 100% gas for performance, or E-10 for availability. Is there a noticeable difference?

For your use and the level of tune on the motor, not enough difference to matter. Whatever's cheapest and available.

[Ric]

Cool, thanks a lot yall!

Oh, and I was wrong on that plug - D8EA, not DE8A.

[Ric]

Time to revive this old horse again LOL!

Anywho, here's my plugs after a good high-rpm chop about an hour ago. This was with my homemade pipes and the old #130 jets I drilled out with a 1/16" bit. Looks much better than the last one - I'm thinking put a pair of #150s in once the pipes come back from being ceramic'd and calling it done. At least till I put the 250 cams in.

20170904_160554.jpg

[Ric]

Here's the other side of the plugs.

20170904_160635.jpg