Lean? Rich? I'm confused....need help before I break it
 

Okay, some may remember almost a month ago I posted about doing a carb sync. I got lots of help, tackled it myself and all was well. Then, I received my K&N block off's about a week ago (already had K&N filter in but no block offs allowing dirty air in) and installed them. Over the past 5 days my bike has been exhibiting a lean situation between 3k and 4K RPM (kind of a stutter,stumbles or misses, subtle, not real bad). It has also been popping more on deceleration (yes the pair valve is removed and all the caps are still in place). These items would make me think of it running lean. So, this evening I do another carb sync, I thought maybe my first attempt wasn't so good or maybe somehow the K&N block off's made a change.
The sync is good but strange, at idle the rear cylinder tends to pull more fluid during the sync (very slowly) and at 4K RPM the front cylinder pulls more with it still stumbling (stuttering, missing, etc.), again the fluid in my manometer is pulled very slowly. Now this is what really confuses me, when I blip the throttle (after carb sync) I get a little black smoke out my pipes (this is between 5k-7K rpm). I thought black smoke meant a rich condition. Also, when I blip the throttle it sounds like ass, like when you have a cold and you have some crap in your throat your trying to cough up. Sorry, that's the best explanation I can give. Other than that the bike idles awesome, no dying but a little hesitation at 1800 RPM when coming down from 4-5k RPM.
So, I'm lost. I'd like to get this correct so I can ride this weekend with the New England group. Any ideas, suggestions? Should I just suck it up and bring it in to a shop? I'm a little leary of that though. Any help is appreciated.

What are your current settings?

:oops: little embarrasing but I don't exactly know how to check/remove the needles or the number of turns for the adj. screws on the carbs. They haven't been touched in the 5000 miles I've had it for. I do have the downloaded service manual but to be honest, I'm a little scared of messing with the carbs more than a carb sync. Guess I should educate myself and dig in or plan on paying someone for there services.

Take it out on a "spirited" ride, bring it home and pull the plugs. Or if you are really anal, and where you live allows for a full throttle run and then pull in the clutch and hit the kill switch coast into garage kind of thing, do a plug chop on it. That'll tell you if you're rich or lean.

what about seafoam? Think this would be a good option to see if it'll help clean out the carbs? Also, anyone think I should spray vacuum lines with WD-40 to check for leaks?

Personally I would just ditch the K&N and run a stock.
Maybe that would be a good place to start.
have you checked all the plug wires?

3k to 4k would be your needle setting. The other thing it could be is your carb slides are hanging up. Since you had been running it with the block offs not in the air box, you could have sucked some dirt into the slides. You can pull the slides out the the carbs with out removing the carbs. When you pull the black cap off there is a spring underneath it. Not a high tension spring by any means, but it can suprize you if you are not aware of it. Take a look at the slides and see if they move freely and that the slide dirafram is not torn. If you pull the needles just note what order the washers are in. If you need to change needle height, raising the clip (lowering needle height) will lean things out, and lowering the clip (raising needle height) wil richen things up.

The way you describe that the bike stumbles make me think more a rich condition. If the bike was surgering that is more like a lean condtion.

if you aren't sure how to remove the needles/jets, or I'm assuming, remove the carbs, it might be a tough go on your own. If you've done it before on other bikes, just get a manual and go at it, if not, you'll want some help.
If you've had it 5k, was it running fine before? did you put the K&N in? if so without jetting changes and it won't run well - lots of fiddling required. So if that is the case, just put a stock filter back in and see. If the K&N was already in place and it used to run well until something you did, try to backtrack and see where you might have changed something. were the 'choke' cables removed or twisted - they are delicate and have been know to break or hang up causing problem as well and easy to check. If the K&N was already in place and its always run poorly then it probably was never jetted correctly. So, need more info here, and just try to backtrack to when it ran well and whats been done since.

I bought the bike with K&N filter installed. I've made no changes to the bike except adding the K&N block off's (were missing from PO). I'm thinking (hoping) it sucked some dirt in the carbs and the seafoam will clean it out. We'll see, if this doesn't work I'll check what FTMS said above.

Might sound stupid but are the velocity stacks in the air box .... i forgot to put them in once and it ran like crap until 5 k :)

Shot in the dark....i put in a flo commander and have not had any tuning issues or sync problems since nice to just lean over and turn a screw to lean or richen the bike out.
There kinda spendy thou 135 bucks i did see one on ebay for 50 bucks the other day
(there all the same just diff lengh hose)

Did it run right when you got it? I don't think that question has been answered.
A K&N requires radical rejetting and if that hasn't been done you are definitely running lean. But you need to know what your settings are now. It's time to learn.
Getting the jetting right can take a little while, but nothing about it is all that difficult. You will get plenty of help here if you decide to tackle it.

Yes, It ran fine for my first 5000 miles I owned it. Starting going bad in the past week.

It's something in New England. Mine is doing the little surge thing as well.

simplest thing then is to remove the KN blockoffs and see if that cures it. I don't know what they are but if they affect how much air gets to the carbs, it may have to be rejetted to work best with those in place, as it originally sounds like it was set up without them. I think any dirt getting sucked in would have gone straight through to the engine without altering your jets or passages in any way. The timing of the new blockoffs and thenew surge, sure point to that.

UPDATE!!!

I tried seafoam this morning and went on a spirited 80 mile ride. By the time I got home there was no more surging, very little popping on decel (maybe one pop out of every 10 times decelerating) and no missing or anything. Seemed to have cured the problem, must have been dirty carbs? That's what i'm hoping. I'm going to go for a 200 mile ride tomorrow and change the oil afterwards. If all is good after that then I'm gonna see the New England guys in VT on Sunday, Yippee!!!!

Glad to see it is running better. You may still want to pull your plugs after the ride. I have a feeling that the sea foam cleaned the carbon off the plugs allowing it to run better. Which would mean it is running rich.

Got it, I'll check that out today. Thanks.

Ok, edumacate me. What is "seafoam" and where is it available. I can infer that it is a carb cleaner, but why is it being recommended over something else?

Thanks.

Erik

I've just heard about it on other forums but it was talked about somewhere on here also. Seafoam is a fuel system cleaner but it can be added with oil also (at least it says so on the bottle). Everyone I've heard of using it says nothing but good things so I thought I'd try. You can find it at any Autozone, Advance Auto Parts or any other auto parts store. The bottle looks like it's from the 1960's. Mine was about $9 for a bottle. You only are suppossed to add about 1-2 oz. per gallon of gas. I had a little over 2 gallons in the tank so I added 4 oz. of it and went for a ride. My bike progressivley ran better as I went along this morning. The bottle says to use once every 2000 miles to maintane a clean fuel system. I think adding it with an oil change will be what I'm doing from now on.

FTMS - I still haven't checked my plugs but I will. One question though, depending on how rich I may be running wouldn't I see a change in fuel mileage? I'm still running between 130-140 miles per tank of gas.

[/QUOTE]FTMS - I still haven't checked my plugs but I will. One question though, depending on how rich I may be running wouldn't I see a change in fuel mileage? I'm still running between 130-140 miles per tank of gas.[/QUOTE]

Your not running that rich that you would see a difference in fuel mileage. You mite be running rich in mid range not top end. If you were changing main jets and running at WOT all the time then yes, you would see a difference.

In snowmobiles when I put twin pipes on a sled and you jump from say #380 to #500 then you see a difference. With most bikes you go up from say #170 to maybe a #185. You mite see a difference in fuel mileage if you are very acurate in the way you measure fuel mileage each time.