Idle problem

[KEITH KRAUSE]

Hi Joe. I only mentioned the air screws (which I have) as a possibility, just like the accelerator pump idea. I can see the confusion over air, idle, and mixture screws. Your description of your screws sounds like the pilot/fuel screws on my bike, very sharp tipped. Mine fine tune the fuel flow for the pilot circuit, and have nothing to do with air flow, I have seperate air screws to adjust the air intake. I don't know if your mixture screws adjust fuel only, or both fuel and air? Do you have a factory manual? I called Dynojet a couple of times and they were helpful with my questions. By the way, if you did'nt know, never tighten down those sharp tipped screws, the tips can break off in the carb body. Just seat them lightly.
You must not have seperate air screws on the side, they are obvious.
Also, I assume now you don't have an accelerator pump either?
What about checking the plug caps/leads/coil connections? Anything?
A weak spark due to a poor connection(s) can show itself sometimes only when hot and/or at low rpm's. A weak spark can easily be confused with a rich condition. How are your plug reads? I have heard it is difficult to get accurate reads at idle rpm's, but have you let the bike idle when hot (with your assistance) and then taken a read? How about the hot and cold resistance/voltage reads?
Going by what you say you've checked, I'm really wondering about your electrical connections. It only takes 1 cylinder to mess up the idle.

[Joe Nardy]

Keith,

Yes, I do have a Haynes manual for the bike. I plan on looking into plug caps/leads/coil connections. I am familiar with volt/ohm meters but I could use some help with what I should be looking for. I'm guessing cold and hot resistance measurements of coils and wires. You mention voltage readings..........what voltages should I be checking? I also have a timing light that I plan on using to see if any wires are firing irregularly. Any guidance is appreciated.

Thanks,
Joe

[KEITH KRAUSE]

Keith,

Yes, I do have a Haynes manual for the bike. I plan on looking into plug caps/leads/coil connections. I am familiar with volt/ohm meters but I could use some help with what I should be looking for. I'm guessing cold and hot resistance measurements of coils and wires. You mention voltage readings..........what voltages should I be checking? I also have a timing light that I plan on using to see if any wires are firing irregularly. Any guidance is appreciated.

Thanks,
Joe

Hi Joe.
I have been lucky over the years when it comes to most electrical problems, so I really don't have a lot of experience with trouble-shooting.
I would have to look at my manual and try to follow their test procedures too. If you do a search here, I'm sure you'll get some help, or maybe someone else can join this topic.
I do know that hot/poor connections can increase the resistance reads, and decrease the voltage reads. I'm just not sure where the correct places are to take the tests. If you can't find help, I'll try to check out my manual and help you. Maybe I'll learn something. Talk to you later.
PS: To me, a poor connection/coil makes sense. Once the connector/coil gets hot, the resistance builds up, and your spark at the plug decreases.
Also, at idle, the voltage can drop, which can decrease the spark. A weak spark will not ignite the mixture well, so you'll get a "rich" condition.

[Joe Nardy]

Keith,

As always, thanks. I'm hoping to get some time today to look into this. I'll see what the manual has to offer and take it from there. I'll post my (hopefully successful) results.

Joe

[KEITH KRAUSE]

Hi Joe. Just had a thought, you never know.
Have you checked the choke assembly? If yours is similar to mine, they are all connected to a shaft, and with vibration, is it possible they are not all adjusted the same? Could 1 or more be hanging up and not fully closing when you turn the choke off? Vibration or dirt/varnish could cause this. Also, if your choke plungers are part rubber (like mine) 1 or more may not be sealing. This would give you a rich condition and it would be most noticable when hot and at idle.

[AOD]

Keith, i dont know if you're CV carbs are the same, but my choke assembly is a bar, yes...but its tapped for the choke screws...meaning they all sit in the same place...and shouldn't stick or go out of alignment unless they are not connected to the bar.

my bike fires up only only 3 cylinders with full choke...it has done this ever since i got it...carbs have been cleaned twice, so i don't know why this happens.

~Adam

[Joe Nardy]

Feeling rather stupid

Keith, C.I.,

I worked on the beloved 'Cane yesterday. After my last ride, not only did I still have the idle problem, the electric cooling fan had ceased to function and the brake light on the GIVI top trunk had failed also. I found a loose connector for the fan and a broken wire for the light. Then I went into the idle thing. I checked the coils and wires for resistance per the manual. All were on the high side of the range but okay. The book says the readings are for 68 degrees and it was around 80 so that may have something to do with it. I pulled the wires off the coils and cut a small piece off each wire so there would be clean wire to contact. I cleaned all connections with a contact cleaner/protector I got at an electronics supply place. Everything looked okay so I put it back together and started it up. The idle was rather low and rough, although not as bad as it gets when hot. I started re-thinking the 'AIR' (big hint right there)screw adjustment and my handling of the 'RICH' condition. It occured to me that I had been adjusting the WRONG WAY! I should have been turning them OUT to get more air and lean it out. I adjusted the AIR screws OUT for highest idle and ended up with them out 4 turns. I went for a pretty long ride and rode hard and fast, then slow in stop and go traffic. I made sure it got good and hot. The idle is still just a bit lower when hot than when warm but much cleaner and stable. I hate to think this whole thing was due to my own stupidity but it sure wouldn't be the first time!

Hopefully this will close this problem. Once again, thanks to everyone who helped, especially Keith. It is all greatly appreciated.

Joe

[KEITH KRAUSE]

I just hope it's fixed! There was some confusion earlier about what kind of screws you have. Right now, your description makes me think you have 1 screw, a mixture screw. When you turn a mixture screw out, you get an equal increase in both air and fuel. On my older carbs, I have a seperate air screw and pilot (fuel) screw. Turning either of these out also increases their volume. Again, hope it's fixed!