Plug Check with Pictures

[ryonker]

I drove my bike tonight and it was awesome. Thanks Steve, Earl, BikeCliff and Dave and so many others!!!! You guys have been so helpful.

I checked my plugs after the ride. Plugs 2, 3 and 4 looked really good. However, 1 was dark and a little sooty looking. It was wet or oily. Just darkened. They are layed down in order 1,2,3,4 in the photos.

What does this mean again? Too lean?

Here are some photos.... any comments would be great! Thanks!

[ryonker]

Sorry, the pictures are not that good.

Here's another one.

[ryonker]

One last photo. Sorry I have to spread these out...I don't think I can put multiple photos on a single post.

[lee1rbc]

its either too rich or it could be ignition related, weak spark. Prob just a half turn back on the idle air screw and try again. 2 cents.

[Nessism]

Dark plug mean it's running rich on the cylinder or has a weak spark - assuming it's not burning oil. Maybe the float height needs to be adjusted or the needle is leaking a little. Weak spark could cause the same problem; maybe a plug cap is getting old and/or the wire is burned on the end.

Good luck.

[ryonker]

So open up the air screw a little? ...as in a small turn counterclockwise?

Or am I closing the screw and lessening the air?

Thanks!

Rick

[TheCafeKid]

I agree. Were I you, id start by pulling the carbs and checking the float hights to make sure they are all the same. Another problem with the VM carbs is that occasionally, if youve started to get some varnish build up in the float bowls, it may not necessarilly mess up the jets, but the floats will sometimes get stuck. After checking float hight, check your fuel screws (the ones on the bottom of the carbs) with no mods, one turn out should be stock i believe. Then check the air screws. 1.5 to 1.75 turns out is generally a good baseline, then once the bike is warm, tweek each slowly, listening for highest idle, and then leave them there, and adjust your idle adjuster back to 1kRPM or so. After that, pull your plug caps off (unscrew them) and trim back the plug wires so you have fresh clean wire exposed (bout a 1/4 inch or so is good) and replace the caps. Then, one at a time check your plugs for good spark. If you have that, you should be good to go. If not, you might look at your points and condenser. It looks TO ME, that the two plugs on the same side there are the darker, so that means its likely NOT coil related, as they are seperate coils, and the same goes for the points. Never hurts to check tho. I think some simple maintainence will solve problem however. Another thing, when is the last time you've adjusted the valves?

[TheCafeKid]

So open up the air screw a little? ...as in a small turn counterclockwise?

Or am I closing the screw and lessening the air?

Thanks!

Rick

Turning the screw OUT (so it starts coming out) will LEAN the mix on your carbs. I would suggest checking all of the above in my previous post, simply to assure you have a proper baseline for tweeking the airscrews. Leaning it out TOO much can have detremental effects on your motor.

[ryonker]

Just got done cleaning the carbs and setting the screws exactly as you mentioned. They are very clean inside)

I just finished adjusting the valves.

I also just put in new points and condensors and set the timing just a little advanced.

I also did the coil mod and I am getting 12v at the coils.

However, I haven't done anything with the plug wires. I am not totally sure if I follow how to trim the plug wires...?

I probably shouldn't be so finicky...the bike ran great tonight,,,, lot's of power, shifted well, sounds great.

I will play around with it and get back.

Thanks for all the help!

Thanks!!!

[TheCafeKid]

Just got done cleaning the carbs and setting the screws exactly as you mentioned. They are very clean inside)

I just finished adjusting the valves.

I also just put in new points and condensors and set the timing just a little advanced.

I also did the coil mod and I am getting 12v at the coils.

However, I haven't done anything with the plug wires. I am not totally sure if I follow how to trim the plug wires...?

I probably shouldn't be so finicky...the bike ran great tonight,,,, lot's of power, shifted well, sounds great.

I will play around with it and get back.

Thanks for all the help!

Thanks!!!

Its simple. The caps, ( the boots that go over the plugs) unscrew from the wires themselves. It takes a lil bit of twisting, but dont worry, you're not breaking it. Once you have them off, what you will likely see is that there is no wire exposed at the end of the plug wire. Its usually, after lots of miles, burnt off and recessing into the rubber. Simply cut some of the rubber off, bout a 1/4 inch or so, to expose fresh clean wire for the contact inside the plug cap. Then screw the cap back on. You might consider, if they are still the stock caps, replacing them. You might find them at Autozone, but if not you can get them from Z1 i do believe. Ive been kinda suprised at the stuff i can find for my bike at the autozones around here. They carry my oil filter, tho its a FRAM, which im not fond of, but in a pinch it will work. They carry my plugs, they can ORDER brake pads and KN filters for it as well.

[psyguy]

it's great you're taking detailed interest in your bike

and looking for best performance

i see tck and others have got you sorted so rest assured that sparkplug IS going to change color

I probably shouldn't be so finicky...

[80GS750]

it looks like 1 is too rich, and 3 is too lean...

just in case no one already mentioned that... lol

[ryonker]

So if 3 is too lean, tighten up the air mixture screw?

Thanks!

[lee1rbc]

Just to clarify.... If You turn the idle mixture screw out (loosen)(counter clock ) that will allow more fuel (richer).

IF You turn the screw in (tighten) (clockwize) that will allow less fuel. (leaner).

I am assuming the idle air screw blockers have been removed, if they have I would first check the setting on all four.

example: screw in #1 cyl idle screw and count exactly how many turns. Then write that down on paper. go to the next one until they are all checked. this will let You know if maybe #1 is way off etc. You might get get a reading like this.

#1 2 1/8 turns #2 1 1/2 turns #3 1 1/8 turn #4 1 3/4 turn.

Then You have a good idea were You want to set Your idle screws. One thing, if Your carbs are not sinked this is a waist of time.

[ryonker]

"Just to clarify.... If You turn the idle mixture screw out (loosen)(counter clock ) that will allow more fuel (richer).

IF You turn the screw in (tighten) (clockwize) that will allow less fuel. (leaner).

I am assuming the idle air screw blockers have been removed, if they have I would first check the setting on all four. "

Hi Lee. If you are talking about the air screw, I just confirmed with CafeKid that tightening it in is richer, and loosening it out is leaner. (opposite of what you stated if I understand you correctly).

I have left my pilot fuel mixture screws right where I set them; 1--turn out. I suppose opening these up would allow in more fuel; if that is what you are saying, thus making them "richer".

Yes, I bench synced and manometer synced the carbs.

Thanks for you input!

Rick