Topic: interesting problem....

[J.Webster Designs]

hey guys.... i had my bike running about a month ago. was running fairly well despite being a little rich. I didnt ever drive it anywhere just around the neighborhood to check the brakes. I came back one time and it was spitting and sputtering like the timing was off on it. no big deal i will deal with the timing when im ready to tune it when its all put back together. i went to start it one day after it had been sitting for a couple weeks and it seemed as if the timing was even further off. backfiring and running roughly. a few carb backfires through carb 4. I went to start it again tonight and it is only running on 1 cylinder. #1. number 3 seems to be slightly warm but 2 and 4 are cold. I am getting spark i verified that today. that really only leaves air and fuel.... i checked that the carbs are getting fuel and they are. I also tried static timing with no significant improvements.

so what say you? what could be causing this deterioration like symptoms? carbs are freshly rebuilt, running stock jetting, Dyna S electronic ignition and 3 ohm coils.

[J.Webster Designs]

could a low battery be causing these symptoms?

[Industrial Cafe]

I think a rich running bike will make the plugs foul after sitting for a while.
that's what mine did till I rejetted.

after you try to start it, pull the plugs and have a look-see, bet they're wet

[J.Webster Designs]

i pulled the plugs earlier today and cleaned them. they were fouled. however, after cleaning there was still no improvement on the 1 cylinder running problem. only thing that i can really think of is that the carbs are getting fuel, but not allowing fuel to the cylinders. i dont see how this is the case as they are freshly rebuilt.

[Industrial Cafe]

eh... hmm.

I use an un-lit propane torch to test if fuel is coming out of the carb into the motor, or if it's the ignition.

even if the carbs were recently rebuilt, that doesn't mean some flakes of crud haven't left the fuel passages and made their way into the jets.

[hapakev]

eh... hmm.

I use an un-lit propane torch to test if fuel is coming out of the carb into the motor, or if it's the ignition.

even if the carbs were recently rebuilt, that doesn't mean some flakes of crud haven't left the fuel passages and made their way into the jets.

I have been told, a few times, that the pilot circuit handles up to 1/2 WOT or more?  You may have crud in the pilot jets from sitting.

[J.Webster Designs]

hmmmmmm....... so drop the bowls and check main jets?

[mlinder]

Pilot circuit handles up to about 1/4 throttle.

Fouled plugs seldom work right after they've been cleaned. I dunno, why, they just don't.

Your idle jets are probably clogged from sitting for that long, so clean them. Get new plugs. A whole set costs, what, 10 bucks?
SO yeah, clean carbs, new plugs, prolly run fine again. You running with the choke on all the time? Why is it running rich? Cleaned the filter?

[J.Webster Designs]

i have it on the initial setting that i set it on when i first got it running. I have been finishing putting it together so that i can tune it and get it running. just now getting to the point where i can tune it.

[mlinder]

i have it on the initial setting that i set it on when i first got it running. I have been finishing putting it together so that i can tune it and get it running. just now getting to the point where i can tune it.

'
What do you mean by this?

[Spanner 1]

Pilot circuit handles up to about 1/4 throttle.....and ADDS its rich/lean mix to the main jetting and needle/ slide open/ close variations...a cumulative effect...

[mlinder]

Pilot circuit handles up to about 1/4 throttle.....and ADDS its rich/lean mix to the main jetting and needle/ slide open/ close variations...a cumulative effect...

True, but the effect diminishes to pretty much nothing after 1/2.

[Industrial Cafe]

i have it on the initial setting that i set it on when i first got it running. I have been finishing putting it together so that i can tune it and get it running. just now getting to the point where i can tune it.

'
What do you mean by this?

yeah.... what do you mean by that?
are you running choked? cause once it's warm you push it down

[Jerry Rxman Griffin aka MuthaF'er]

could a low battery be causing these symptoms?

Low battery - YES  Bad battery - YES

Charge it well. Check the voltage. ~12.6V is normal in resting state. Let it sit and see how long it takes to drop. If you start getting a significant dropoff it may be new battery time. If the battery is suspect at this point remove the headlight fuse and see if your results improve when starting. Do your turn signals blink and beep at the normal rate? How well is the starter motor turning?

Doesn't take much to waste a good battery.

[754]

Open & close gas cap before you start in case vent is clogged, turn gas to reserve.
 Make sure you did NOT pinch fuel line, putting tank into place..

[J.Webster Designs]

What do you mean by this?

yeah.... what do you mean by that? Shocked
are you running choked? cause once it's warm you push it down Wink

ok.... when you rebuild the carbs... you set them to the initial settings... (e.g. 2 turns out, 1.5 turns out) that is what they are set at right now. I have not tuned the carbs. I am not running the bike in the choked position. only during cold start then off when the bike is running.

Charge it well. Check the voltage. ~12.6V is normal in resting state. Let it sit and see how long it takes to drop. If you start getting a significant dropoff it may be new battery time. If the battery is suspect at this point remove the headlight fuse and see if your results improve when starting. Do your turn signals blink and beep at the normal rate? How well is the starter motor turning?

Battery charged over night and will continue to charge until i get back from classes at 2 or so. it died last night after cranking for a while. starter motor runs fine when the battery is charged......

Open & close gas cap before you start in case vent is clogged, turn gas to reserve.
 Make sure you did NOT pinch fuel line, putting tank into place.. Cheesy

lines are fine petcock is flowing fine, no vent blockage. if the battery does nothing then i will pull the bowls and see if something has gotten into them.

[mlinder]

What do you mean by this?

yeah.... what do you mean by that? Shocked
are you running choked? cause once it's warm you push it down Wink

ok.... when you rebuild the carbs... you set them to the initial settings... (e.g. 2 turns out, 1.5 turns out) that is what they are set at right now. I have not tuned the carbs. I am not running the bike in the choked position. only during cold start then off when the bike is running.

Alright, that still doesn't tell us how you've set up your carbs. How many turns out? What position is the needle in? Does it have an air filter? Is it new? If not, was it cleaned? Etc.

[J.Webster Designs]

everything was set to the specs in my clymer when putting it back together (not sure what those specs are off hand as i am in classes.) either way, carb settings will not cause a problem like i am experiencing. the bike was running fine on the settings that its at when i first started the bike after getting the motor back together. It is a deterioration type problem and i just don't see carb settings causing that. air filter is a recently cleaned and oiled K&N.