Okay, so after a few hours of work, I got the carbs synced evenly while at operating temperature and while at idle. It took a lot of adjusting of the 3 screws to get it right and it seemed like as soon as I'd test it by giving it throttle, the vacuum across all 4 carbs would deviate from the "equilibrium" that was just present before! What a pain..

I felt like I needed to do this carb sync because my idle, since purchasing the bike, has always been "rough." I mean that in the way that once the bike is warm and off of the choke, the needle for the tachometer wouldmove side to side within about 300rpm and would never stay "fixed" at let's say 1200rpm. Instead it wouldcontinually 'bounce' within 1100-1400rpmand I never knew what caused this.

Aftermy first carb sync, Irode the bike and it felt smoother than before. However,the sync did not get rid of the rough idle. The bike starts well but this pestering idle bothers me. So what's causingit? Is this what all carbureted engines do?

I feel that one of the following is the cause, but I want to hear from others what it might be, whether from speculation or experience:

-coil packs
-vacuum leak
-A/f mixture
-fuel pressure
-carbs not synced accurately

 

it may be a slight vacuum problem but carbed bikes will never sound as controlled as an EFI bike...my f3 fluctuated a little bit but i don't think it was as much as yours is

 

carb sync #2, and still rough idle present

 

my f3 bounces between 1200 and 1500 rpm and i was told i need a tune up... havent gotten around to it cuz i dont have the cash right now for myself.

 

Can someone take a video of their bike's tachometer @ idle? I couldn't find any close shots on Youtube.

 

i'll post a video tomorrow to dark right now.

 

Thanks a ton. Have it be for 30 secs or so, I want to pay attention to any fluctuation of the tach needle and the sound of the exhaust and all.

I've done 2 syncs and now the spark plug colors have evened out acceptably. I've sea-foamed the carbs via the throttle bodies and via the gas and I still have this rough idle.

I';m now pulling towards ignition issue. My bike rides too well for it to be dirty carbs or something like that. I just don't want to buy two coil packs if mine are working properly!

Any way to test them out for resistance or something?

 

seafoam isnt a sufficient cleaning of your carbs. pull them off the bike and dismantle to clean them physically with tools. seafoam can only help to a certain extent. it is NOT a 100% guarantee your carbs are clean.

have you tested the spark on the plugs? connect the plug to the wire, and ground it to the engine, while holding a rubber part of the plug boot far from the plug and you should see a fat blue spark.

99% of the time coil packs dont just go bad. plug wires can and do get old and not work as well as they should, plugs get older and start to act wonky after awhile, and gummed up carbs will do this too.

a low end power issue indicates to me that your pilot jets need to be cleaned most likely.

 

Again,my bike runs fine through all the gears except when leaving a stop. When taking off from a redlight, for instance,it will be "jumpy" at slow speeds and at small throttle openings.

The idle is smooth for a sec or two then a little sputter, then back to smooth then sputter. Its not a miss though, because if I idle it without a plug wire connected then it's way worse than this. Plugs, fuel filter, airfilter are all good.2 carb syncs(at diff. idle speed each time to try it out) and no difference.When the engine iswarm and idling, if you grab the throttle and rev it, sometimes it will have a little hesitation before it revs up, or sometimes stall out. But sometimes you do this and it will rev right away. Also, it has after fire "popping" when I close the throttle.

I've searched about this and heard aboutpilot screws needing adjustment. Are these on the carbs externally, by any chance? How about an Air/fuel adjustment anywhere?

I'll do this tomorrow then!
Will I see this fat blue spark in the daytime ? Also, will it be okay if that spark plug hole is open while checking this? The motor will still run, but then wouldn't that pump gas up out of the plug hole?

 

from the angle of your plugs..your other ones actualy look like your running really lean..What size jets are you running do you know?possiably time to take the carbs out and cleaned..the idle jet in your carbs have alot to do with your idle..maybe adjust your idle screw if you havent already..Wait till your bike is at operating temp. and slowly adjust that screw to about 1200 rpm's until the idle is just right...an improperly adjusted idle screws can actualy effect plugs in a bike way.