Is this a good spark plug colour ?

[Guest]

Long long time ago, I came across an interesting website regarding motorcycle education. www.dansmc.com. I think most of you will recognize this site. Written in a humorous way, you will spend lots of hours reading and smiling, ánd most of all learning a lot of very interesting information regarding our passion.

In one of the topics, ‘reading spark plug’ is dealt with. My spark plug is ressembling a lot like number 22/23 in that list. Unfortunately, the information is not decisive whether or not this is a good condition for my beloved spark plugs…

Can you please comment if OK or not ?

Modifications to the bike ? yes, I was forced to go to a 4-1 as the original headers were rusted. Stock airbox, K&N replacement filter, no changes to the carbs (so OEM jets and settings).

Feel free to make suggestions to new carb settings for the GS1100GL. I will do anything to make this bike run in an optimal way...

[gert du prez]

For what it's worth:

the bike runs great
synched 2 months ago
idles OK at 1,200 rpm
pulls strong in all areas

[7981GS]

Take your fuel screws out about a half turn and change the main jets a couple of sizes larger.

Daniel

[gert du prez]

changing jets like in
'buy a stage 1 dynojet kit'

or stage 3 ?
or just some loose jets ?

[7981GS]

http://www.z1enterprises.com/SearchResult.aspx?All=True&KeyWords=Mikuni%20jets

Daniel

[Rover]

"bike runs great"

Why do anything?

[Tom R]

The plug color indicates it's running a bit on the lean side, which you'd expect with those modifications. It's probably running hotter than it needs to - and that's not good for the bike.
Also, though I don't have the same bike, I'm pretty sure the instructions with that pipe and air filter recommend making the changes 7981GS posted.

[gert du prez]

and by any chance, you guys know by heart what main jet I would have currently ?
have not opened the carbs yet, but I was just ordering some stuff at Z1 so this can easily be added...

what do I need to buy as main jet ?
no other pilot yet ?
and no 'raising the needle' as I often read on the forum ?

thanks for the assistance so far,

Gert

[rustybronco]

How about some real pictures of your plugs? (nice big ones)

[gert du prez]

Hi,

went out for some pictures, and now I'm sure, photography tips and tricks is probably another forum...

sharpest picture that I could take...sorry for the quality...
I can re-assure you, this looks like picture n°22 as mentioned above...

In reality the spark plug tip looks a bit more brown than shown in the picture.
The 'shaft' under the tip is plain white...

If you can tell me how to make sharper pictures, then I'm interested in that too. But do the jetting first please,
more interested in the GS than in the Sony...

[rustybronco]

from what I can see, I'd raise the needles one half step. what colour do you see way down deep where the center insulator meets the outer shell? brown/ black/ none?

how many miles are on those plugs?

[gert du prez]

can answer the colour question tomorrow (it's late here in Belgium)

The spark plugs are new. 500 km (350 miles or so)...changed these
when I went from the OEM 4-2 to the 4-1...

[rustybronco]

Gert, the only reason I suggested raising the needles is because you said there was no colour on the center (insulator). if there is a light tan or gray colour, by the way it runs, personally I'd leave it alone.

[gert du prez]

does raising the needle always goes hand in hand with a larger main jet ?
or are there reasons why you would only do one of the two changes ?

[rustybronco]

Main jetting, part throttle and idle are three different circuits. they should be checked and adjusted as such. I would not group them as having to wholesale change them all when adjusting one.