question about syncing carbs... or lack thereof

[twiggy2cents]

Okay i have tried to sync my carbs using the ATF in tubes method that someone else did. but anywho say i havent done it yet, here is my situation.

I had a problem with flooding on cyls 1 and 2 at like 30 to 50 mph in 6th gear(about 3000-4500 RPM). These carbs are siemese carbs and there is only a 1and2 sync to 3and4 setup. I have replaced the carbs with ebay ones with a dynojet kit. Same cyls still problem. at 60 and up midrange looks good, maybe a tad lean. I am on 3 up from bottom on the clip. But when it malfucntions it is coal black on 1 and 2. This bike will idle till it starts to get hot then gets rough. The sync is constantly changing on the gauge. As dramatic as setting it even on the tubes then revving the engine and its out of sync. I replaced the coils with used coils and still have the same problem on same cylinders. also it idles rough under 1200 rpms. I have set the carbs for highest idle and have tryied way lean on the screws with same problem and way rich with same problem. Also when it screws up it affects the idle portion too. Im guessing because i dont notice it untill its drowned out the cyl's. Then you let it set for a bit then run it for a while and it clears up

Ive bench synced both these carbs and the others i had on before.

So my question being could a sync be out far enough to do this yet it idles somewhat decent?

Should i be able to idle at like 800 or lower smoothly( i know not to, just wondering)

Is sync usually hard to consistantly set or no?

[Roland]

question about syncing carbs

Hey Twiggy,

According to the manual carb syncing should take place at 1500 rpm less than that you can expect it to be a bit rougher of an idle. I would be very surprised if it would idle below 1,000. The longer you idle the faster your plugs will foul out.

Did you calibrate your meters on the same carb before you started the actual syncing?

If you can get it to idle properly syncing becomes very easy if you have the special carb wrench

[twiggy2cents]

man i wish i wasnt too cheap to buy that wrench it really sucks with out it!! and also my idle spec is 1000 +-100 and i was just wondering if it should struggle down low or if that was a symptom

[twiggy2cents]

http://www.thegsresources.com/_forum...40&postcount=1 this is my sync tool except with two tubes instead of 4 and the lines are the same length

[Killer2600]

Your too rich on 1 and 2, need to fix that before trying to sync the carbs...A bench sync will get you close enough to diagnose running issues.

If the same two cylinders have persistently been a problem after trying two different carbs on them then you probably have an ignition or exhaust issue.

Like roland said once you get the bike idling and running right, syncing the carbs will be easy.

[twiggy2cents]

i think its sync again i can screw the screws in all the way and it just makes it run real rough at idle but still goes rich on those two. Also i have dropped the needle all the way and it still does it. I have replaced the coils and there is nothing electrical pairing 1 and 2. The exhaust has a crossover piece in the middle i can plug off either tail pipe hole with no difference between the two

[Steve]

You changed the carbs.

You changed the coils.

The problem is still there, meaning it wasn't the carbs or coils, but something that you did not change.

Did you adjust the valves? That should be the first step of any tune-up.

.

[twiggy2cents]

yes i have adjusted the valves and compression was at spec, even across.