Plug colors

[D-Max2012]

Hey guys,
Yesterday, I finished up working on my 91.
Changed out: valve cover gaskets, coolant, oil, oil filter, and plugs.
I Changed out the plugs last summer, around this time of year.
I let her warm up till the fan kicked in and took her for a little ride up and down the block.. can we say "disturbing the neighbors", boys and girls..

Anyway, this pic is that of the old plugs..
Just wondering what the color tells you about how each cylinder is running.

 

[Lew L]

Hi,
Looks a bit (?) rich to me ----but your only seening how the bottom half of the rev range is fueling. Get out some place where you can open her up some and do a "chop" ( = high RPM, pull in clutch and cut ignition, coast to a stop) Have a smoke, drink, whatever and then pull lthe plug and read it.

You'll get a much truer picture of the carb tune where the motor is making power.

Lew

 

[D-Max2012]

So I should do this now that I have the new plugs installed.
I've been running these plugs (in the photo), since July 2013.
I have ridden her hard countless times. This test must be done on new plugs?

Yes, it was running rich.. My buds riding behind me said they could smell raw fuel.
yesterday I re-adjusted the AF screws from 3.75 turns out, to 2.25. I'm wondering if I should adjust the needles from center position from blunt end, to 1st position from blunt end, to make the needles sit a bit further in.

 

[MaxMidnight]

You can spend a lot of time and effort doing plug chops...far easier in the long run would be to get a baseline dyno reading which will give you the air/ fuel ratio throughout the rev range.

 

[06VMAXIMUS]

#4 looks way richer than the other 3.

 

[davesax36]

I vote for #2,but I'm bad at this stuff, and the other guys are correct about reading after a chop.

 

[DMAN999]

They doo look rich.
This is what they should all look like:

 

[D-Max2012]

I did a test ride today to Bear Mountain from my home. About 38 miles one way. After adjusting the AF screws to 2.25 turns out, I noticed that raw fuel smell at idle is gone.. Also, I no longer have a slight lag when the engine is warm and roll on the throttle to start moving.. So, riding 76 miles round trip, I only used $10.00 in regular gas @ 3.35 / gal (2.98 gallons). Not bad at all.
Last weekend, the same trip made my fuel light come on near that same gas station.. Bike pulls hard, and that's a bit addictive.. I normally keep her around 75 on a nice stretch of highway (no cops- LOL).. I got a little crazy today and took her up to 114. Felt good execpt for a little handelbar wiggle at that speed. I need that spanner wrench to tighten up the forks a bit.
Anyway, I plan to pull a couple of plugs to take a look at em tomorrow.

 

[Lew L]

Leaned it out and it runs better---Happens often here.:eusa_dance:

Sounds like a carb sync. is in order. I have a Morgan carb tune and it works great!!!! Easy to use also.

Lew

 

[davesax36]

How far out were the screws when you started?

 

[D-Max2012]

From Lew L
"Sounds like a carb sync. is in order. I have a Morgan carb tune and it works great!!!! Easy to use also.",
I have the Syncmaster Pro (blue fluid).. I didn't re-sync them since i did not touch the carbs during all the work over the past couple of days. but i did sync them about 2 weeks ago.

DaveSax36 - They were 3.75 turns out. Now I have them at 2.25 turns out. I plan to lean it up just a touch more to see how she responds.. maybe 2.125 or even 2.0.
I have Mikuni 152.5 all around.
The Previous Owner put the adjustable needles (5 postilion). I have them on the third from blunt end. They seem to be fine, so I'll leave them in there plus i like being able to adjust them if needed.