Bonneville America Forums Forums Technical Forums General Tech 04 America Issues

Hi everyone, Thanks in advance to anyone that attempts to help. This is going to be a little long winded to accurately give the symptoms and performed attempts to remedy this.

6 months ago I decided to add to the fleet and grabbed an 04 America with 700 miles on it in mint condition for a song and a dance. I know the guy and he took great care of it and was sad to let it go but times were tough. He left it sit with fuel in the tank and the carbs and it wouldn't even run. I will preface this with I am auto technician and I am pretty good with bikes (not saying I know everything) so I proceeded to research the hell out of this bike using these forums and whatever else I could find. My starting point with the bike was an in frame cleaning of the carbs and install of a stage 1 dynojet kit, removal of the AI system. removal of 3 baffles per pipe and a K&N filter. After completion the bike came to life right away, idled great, you could snap the throttle and it reved fine but if you tried to maintain a steady rpm at anything less than half throttle it would stumble and sometimes huff a little black smoke. I assumed that I had missed something so i removed the carbs entirely, stripped them and soaked them in a vibrating dunk tank and reassembled them to dynojet instructions but got the same results. I have since then checked all of the fuel screens, removed the anti tip over valve, checked that the fuel vent and cap are correctly venting and made multiple carb adjustments to try and figure this out. It is currently sitting with a 124 main, 42 pilot and needle set in the middle, float heights are verified at 17mm per the manual. I am at loss no matter what I do the problem persists, it idles great I can ride it from stop light to stop light perfectly fine but if i try to cruise at any mid range speed people look at me funny cause it bumbles over itself but if I crack the throttle she wakes right up, I can accelerate from a dead stop with a little hesitation at take off but then all the way to highway speeds and cruise at 70mph and up seemingly perfectly fine. I know that these bikes tend to have electrical problems but the fact that its only between 1500 and 3500ish at steady throttle and runs great beyond that makes me have a hard time pointing at anything ignition related. I just want to ride this beautiful machine before it starts snowing.

from what you describe I would check the pick up coil gap and make sure it is set to the updated spec of .8mm. I would also take a close look at the slide diaphrams since it sounds like they may not be lifting the slides right causing a rich condition. Be sure the choke is closing (enrichener actually). Sync the carbs, and check the float level with a piece of clear tube, put the clear tube on the bowl drain and hold up along side the carb then open the drain and the level should be just about even with where the bowl meets the body.Could try dropping the needle a notch too. these are not necessarily in the order to tackle them in just ideas to check. Make one change at a time and look for results so you can determine what works and what doesn't.

This may be weak at best considering the advice Ian suggested and the fact you've checked the filters. But what about the hidden filter? I don't think it would matter much in this but.......

How many turn out are the pilots?

Hidden filter is a very good idea if it has not been removed, pilots too. Sometimes I overlook the simple stuff assuming the person had already done them.

I have removed the hidden filter, verified float height twice, I have gone up with the main jet and down with the main jet as well as up and down with the needle and in and out with pilot screw and nothing shakes that hesitation at 1/4 throttle. I have intentions to remove the slides tonight when I get home from work and make sure that I did not install the retainer for the needle over the vacuum hole(great info I found from a few guys in another thread) as well I was going to swap the pilot for a 45 and adjust my main and needle accordingly from the jet calculator seeing as through all of this the only thing I haven't changed is the pilot jet.

If you are blowing black smoke you are rich so don't increase the pilot especially if you still have the stock air box in place.

May want to disconnect the TPS also, may not help but for sure wont hurt.

Hello Richard and welcome to the forums.

Assuming you are running rich as Ian stated (black smoke) the first thing is to verify the float height with a clear tube. I know you already checked it twice but the tube test doesn't lie. You will see how much fuel is actually getting into each bowl and might notice one or both are too high.

Did you forget to install the needle collar or put it in backwards?

Is the Dyno jet kit the right one for your bike? You might want to get the original needles and install them as a test since the original usually run a little lean in the midrange.

You didn't state whether the snorkels were removed?

You also could pull the filter and install a mirror in the air box to see if the slides are opening when the throttle is blipped. Never tried it myself but just trying to think out of the box.

Are your plugs black?

Ok i just came in from the garage and i took off the tops ad the needle retainers are lined up right, i have already disconnected the tps and there is no difference either way.The snorkels are still in, stock air box with k&n filter. And Gregger I put all of the stock equipment back in the carbs and got the same results. My whole problem is I never heard this bike run without modifying the intake and exhaust so I have no base point to start from. I did not end up trying the larger pilot because the dealers around here are useless and although they said they had the jet they didn't. I was only thinking of increasing the pilot because there was a lot of info I found in reguards to changing the pilot because of a more open exhaust.The other thing that boggles my mind is that yes the Dynojet kit is correct and the trouble shooting guide with it says that if I have a problem during cruising that I am lean, but my plugs seemed a little dark to me but the richer I seem to set everything the better it runs just still has the same stumble. I punched everything into the Jet calculator I found and even if I leave the pilot alone I am according to that running to lean of a main jet but basic carb theory says that isn't causing my 1/4 throttle issue.

Just opening up the exhaust will not make a huge difference if you don't open up the intake side too. You may have a bad needle or seat on one of your floats, or some varnish or dirt not allowing them to close properly. Trouble with this type of problem and not being able to hear/see things for myself is it is hard to diagnose.

I can understand I am banging my head against the wall. I replaced the needle and seats and have soaked these carbs twice.

You have to figure out if the bike is lean or rich in that throttle range.

How many turns are your idle mixture screws out? 2 to 3 is ok. More than 3, go to larger pilots. The idle screws are good up to around 1/4 to 1/3 throttle.

Next are the needles. Were the needle collars put back in place after the carbs were pulled apart? Are the slides opening? You didn't say?

Next is carb balance. Have you checked to see if the vacuum is the same between carbs with the engine at fast idle? The balance screw is situated between the two carbs. This can cause your engine to feel like it is running on one cylinder if out a lot or vibrate/buzz if out a little. Check to see if both pipes are the same temperature while idling.

You need to perform one change at a time then test.

My 03 is set up with 135 mains, 42 pilots, 2.5 turns out on the idle mixture screws, TBS needles (richer than stock) flow through TOR pipes, all three snorkels removed with the filter retainer opened up to increase airflow complete with a UNI filter. Your setup should be the same or similar to mine.

As Ian stated, it is very hard to help diagnose the problem not being able to hear, or determine if the engine is running rich or lean. Do the simple things first.

Still would like to know what your float height is using some tubing. This takes all the guesswork out and is very simple to do. (piece of clear tubing placed on the float bowl drain then run it up beside the carb. Open the drain screw and measure where the gas climbs to.)

I will try to locate some tubing and check that way tomorrow after work, I think I saw somewhere that 1/4 inch is the magic number.

The slides were opening before (I haven't checked since th e last assembly I just assumed because I can ride on the highway)

The pilot screws actually seemed top settle the idle best at 3 1/2 to 3 3/4 turns out

The needle collars if those are the two shims on each needle than yes

Am I correct in assuming ths there is a thread on how to sync by vacuum because that is one thing I haven't done

Are you referring to the emulsion tube that the main jet threads into our is there another piece above the emulsion tubes for the needle?

Is that collar supposed to come out with the emuslion tube because from the first time I took these carbs apart I have never seen that collar piece. Son of a... I will piss myself laughing if it is that stupid.

Is it possible to just order the collars if that is the case.

that collar ,in my experience, generally doesn't fall out but in some cases it does. I have to wonder if it is because they are not manufactured as well as they used to be.

I will check that when I get home tonight but if they are missing do I have buy carbs or can I get those collars? Would those also be referred to as the needle jet.

I think needle jet refers to that whole assembly.

The collar will stick. Or may not. Being as how you soaked your carbies, with majic fingers, err a vibrating tank, and if you did so with the main jet emulsion tube kit removed, well never mind. Look in the tank for them!

Read this over at ThumperTalk.com.

I called my buddy and he didn't find them on the bench or in the carb soaker at his shop which means that when the guy tried to do them the first time he lost them. I am going to take a ride home on lunch and take a second peek but I am almost sure that there wasn't anything protruding into the main bore of the carbs at least on the left side that I looked at this morning before work. Oh well gives me an excuse to pull out old faithfull(02 CBR954rr) and ride it back to work because the weather got nice.

If they are missing you found your problem.

I was going to embed that pic here but not sure if that would be allowed since Moe didn't. Is there something about TT that they don't want the pix embedded here?

It is good practice to copy a picture from a website to a site you use. Like photobucket. Showing it in a post linked to the site (in this case Thumper Talk) uses there bandwidth and is frowned upon.

btw, ours don't protrude as much as that one does.

Well low and behold there is no brass collar staring back at me when I look down the slide bore. Thank you so much to everyone,I am so exited to enjoy this beautiful machine. I found the collars in England should be here mid week. I also ordered the appropriate jets necessary for the air box mods I will do while I'm waiting for the collars lol.

He's a shot from B02S4's post on CV Carb Tuning.

Yeah they definitely aren't there, and they couldn't have been there since the point that I bought the bike because it has had this issue since day one. I am just glad that we found it. I am going to pull the carbs again for hopefully the last time, I have to helicoil one of the bowl screw holes and I am going to drill the airbox and remove the baffle inside. I will keep everyone posted. Thanks again.

Glad you got it figured out, wish I could have been more help. Well, at least I learned something.

I am still waiting for parts, holy crap I hope they show up soon I am running outta nice weather.

I know what I'll be lookin for tonite,thanks guys this thing with Nanci's bike has been buggin me fer a couple years.

Ok collars came in! I assembled the carbs and threw everything back together. It was running better than before so I synced the carbs and set the pilots. Holy crap were they out of balance. Either way the collars did it I have about 100 miles on it now and it runs like a dream. Thanks everyone that tried to help. It is going to be 80 degrees here this afternoon. Can't wait.