Is this too Lean??

[Guest]

Ok, long story short. Replaced drilled out Original exhaust with un-molested Original exhaust. Had put larger main's in for the drilled out, so went back to stock for the un-molested.

Have about 2 hours of riding on the new un-molested exhaust (my ears and I'm sure my neighbors are thankful) and this is what #2 looks like.

{click image to open larger in a new window/tab}


So, is it running too lean? I'm thinking it's right on the edge of being acceptable, but would like the collective thoughts from those on here to confirm or deny that.

1981 550T Stock intake and (now) exhaust.

Thoughts?

Amos

ps vacume line is suple and attached.

[mrbill5491]

Look way lean to me. should a tan color. Did you do a plug chop?

[TheBigRed]

Look way lean to me. should a tan color. Did you do a plug chop?

Not really, just took a look after it had cooled down from my ride home from work. The rest are more tan, just that one was more on the white side as seen. The flash may be making it a little whiter than it actually is in that picture, let me upload one that was taken without flash (though the camera had problems focussing on the plug in it.




Amos

[Nessism]

Doesn't look too bad to me. How does it run?

Assuming it runs well, has stock intake system, stock exhaust, stock jets, and everything is sealed well, I wouldn't worry too much.

If the bike is cold blooded in a serious way you might want to consider shimming the carb needles. The carbs can stay on the bike, just remove the top cover and pull out the slides w/needle. After removing the needle you want to remove the plastic spacer on top of the clip and replace it with a washer stack that is roughly 1/2 as thick as the spacer. Put the bike back together and see if it runs better. Another thing is to open the mixture screws until they are at 3 turns from lightly seated. Fine tuning steps like this (and vacuum sync of course) are what separates a really nice running bike from one that just runs decently but lacks refinement.

Good luck

[TheBigRed]

It seems to be running well, no noticeable stumbles or anything. I haven't gotten it onto the highway yet to see how it is for any sustained highway speeds. but I've had it.. Ok, close to not knowing how fast I was going.

It really isn't cold blooded at all. Actually, probably better since the switch. This morning I was off choke pretty much within a minute of starting.

Amos

[steve murdoch]

I wish mine looked that good!
That shade of tan looks fine to me.

[Griffin]

Gray or tan is fine. It's the chalky white that you don't want.

People get really hung up on plug colors, and while that's an important indicator of how your engine is running, it isn't the end-all, be-all indicator. Stumbling at certain rpms, throttle hesitation, backfiring, excessive vibration, exhaust odors, etc... all have to be considered when tuning an engine.

I think those plugs look ok. Perhaps a tiny bit lean on the first one, perhaps towards the richer end on the second, but your engine runs leaner or richer depending upon varying atmospheric conditions.

If the other indicators of engine tune are ok, I'd be satisfied with it. Ideally you want all four plugs to be identical though. Have you synch'ed the carbs lately? Adjusted the individual air mixture screws to attain the highest rpm?

[TheBigRed]

I think those plugs look ok. Perhaps a tiny bit lean on the first one, perhaps towards the richer end on the second, but your engine runs leaner or richer depending upon varying atmospheric conditions.

Griff, Those are both the same plug, one pic with flash, one without.

If the other indicators of engine tune are ok, I'd be satisfied with it. Ideally you want all four plugs to be identical though. Have you synch'ed the carbs lately? Adjusted the individual air mixture screws?

Sync was done last year, but not since this latest change.

Amos

[Griffin]

Griff, Those are both the same plug, one pic with flash, one without.

Amos,

Then you're good. I'm assuming that it looks lighter in the first pic than in person, and darker in the second pic than in person.

You're golden.

[mrbill5491]

Okay this is the pic with no flash, the plug looks fine. Guess the flash tends to wash things out white huh.

Not really, just took a look after it had cooled down from my ride home from work. The rest are more tan, just that one was more on the white side as seen. The flash may be making it a little whiter than it actually is in that picture, let me upload one that was taken without flash (though the camera had problems focussing on the plug in it.




Amos