[akarob]

You can safely unplug the fuel line and no gas will come out, other than what is in the hose already. As said, it won't allow fuel to pass unless the engine is running.

You can run the bike without fairings. I suggest leaving them off until you get your issues figured out.

So you say it idles fine? Make sure all cylinders are working by spraying water on the hot (or not) pipes.

I'd replace the spark plugs for sure then check the following:
good spark
cylinder compression
carb synchronization

You'll probably find something obvious.

[Syndacate]

When I had fairings I'm pretty sure I could get the tank off without pulling the fairings by pulling the fasteners from the rear of the front fairings and pushing them out enough to lift the tank up.

By plug wires, I mean just the wires themselves. Not the boots and not the coils. If the coils test out fine, then there is no reason to replace them. The boots don't go bad very often, but if one is cracked or something then it should be replaced.

Yeah, that's what I was thinking (about the tank). I'll give it a whirl when I get some free time .

Well there was only 3k on the bike when I bought it and it was 13 years old..doesn't take a rocket scientist to determine that the bike had to be sitting a decent amount of time, even if it was claimed not to have been. Knowing that it probably sat at some point, it's quite possible that the rubber in and around the plug wires is dry-rotted. I was hoping to take the tank off and pull all plugs and wires and have a look-see.

You can safely unplug the fuel line and no gas will come out, other than what is in the hose already. As said, it won't allow fuel to pass unless the engine is running.

Yeah, I think I said that before I realized that the petcock was attached to the tank, not the carb side.

You can run the bike without fairings. I suggest leaving them off until you get your issues figured out.

Yeah, but it happens under load, and with time delay, that means time driving on the road - time driving on the road without mirrors *shutters*.

So you say it idles fine? Make sure all cylinders are working by spraying water on the hot (or not) pipes.

Yes and no. Before I dicked with it, when it was SOAKING outside, it would be popping a little at idle (misfires). Then when I get on and road I'd felt the power drop. After I pushed the wire back into the head, it idled like a champ (it was also bone dry), but after a 10-15 minute ride when I heard it pop, it was popping at idle.

Then I rode it back here and it was nasty misfiring until like 5k...

Then I start it up today before I went to class and it idled and ran 100% okay, just like new. WTF??? So I rode to class, and back, and not a single hiccup. It was bone dry when it was misfiring like a ***** the other day, unlike prior to the tear-down when it was only happening in the soaking wet..

I'd replace the spark plugs for sure then check the following:
good spark
cylinder compression
carb synchronization

You'll probably find something obvious.

Yeah, first I'm looking at the wires, and probably the plugs, as that's where I think the problem is. I don't see a carb synch causing this type of problem, but it's possible I'm wrong, same goes for a compression test.

To me, popping, misfiring, running on 3 cyl in the wet, popping on let off, those are all signs of no ignition. There's something with the ignition system for sure..

I was just thinking on my way home today, if I can get it to do it while it's idling like it was a few days ago I can hook up a timing light and possibly see which one's not happening. Help me hone in on the problem a bit...but for that, I need the tank off..as I can't get to the wires realistically..worth a shot though if I can catch it when it doesn't want to idle again.

[jimbowv]

you can have your plugwire coil checked at a dealer for about $25 but when they go bad ..they go bad check plugs for gaping...i had the kind of the same problem i pulled the carbs cleaned them check vac line and fix it right up...hope this helps

[downrangefuture]

Running too lean can cause all of the issues you described. I know carbs from my first truck were really sensitive. Dropping 15 degrees in temperature, or changing pressure from changing 2000feet in elevation can cause carbs to run lean. The barimetric pressure falls that far and the temp can easily drop that far when it's raining. I would have to reset my carb in the truck every time I went from home to college.

That's why everyone keeps saying to check the carb. I was going to say you could buy my spare set of coils, but I don't think pre/post crossover works there.

[Syndacate]

you can have your plugwire coil checked at a dealer for about $25 but when they go bad ..they go bad check plugs for gaping...i had the kind of the same problem i pulled the carbs cleaned them check vac line and fix it right up...hope this helps

Really? Mucked up carbs caused a cylinder not to fire? The thing is due for a carb cleaning come spring, though I'd like to get this issue resolved before the snow hits the ground. Right now on the to-do list for spring tune-up is:
- front brakes
- oil
- clean chain very thoroughly
- flush both brake fluids, new DOT4
- change oil in cooler if different from lube oil (still not sure if they're separate systems)
- chain adjust (*chatters*)
- clean carbs
- sync carbs
- clean filters/air boxes

I think that's all that's on the agenda before I sell come spring..even if I don't sell in Spring, the carbs probably have never been cleaned nor synced, probably original chain at 5k miles, wouldn't surprise me if it was the original oil..same for everything else. A lot of Suzuki stickers won't surprise me on this tune-up. Not to mention the previous owner only front braked .

Either way, I'd like to get this ignition issue cleared up before I get to the tune-up, those things can wait a few hundred miles, this can't .

Running too lean can cause all of the issues you described. I know carbs from my first truck were really sensitive. Dropping 15 degrees in temperature, or changing pressure from changing 2000feet in elevation can cause carbs to run lean. The barimetric pressure falls that far and the temp can easily drop that far when it's raining. I would have to reset my carb in the truck every time I went from home to college.

Why I'm looking to upgrade to FI...

My camaro sucked in its snow, it's the only carbed vehicle I've owned..so it was only out in the Summer months.. I can definitely see the altitude changing having a same effect, but the bike is in the same environment..

I ****ed with the left side spark plug wire through the fairing the other day (dry as a bone) and it started up and ran 100%. I rode it for like 10-15 min extra after class and noticed a serious bog under 3k that wasn't there before class. I'm definitely leaning towards something with the coils or wires (more likely the wires) as I definitely think vibration has something to do with it (something loosening up or something..not to mention it was a whole 1" out when I first looked at it..it has to be there... ).

I'll keep in mind, though, the sensitivity of the carbs. If they can wait until Spring to be cleaned than I hope I can leave them until then.

That's why everyone keeps saying to check the carb. I was going to say you could buy my spare set of coils, but I don't think pre/post crossover works there.

So if I do get new packs, they have to be from a '91-'97 Kat?

Also, for $25 a coil at the Suzuki dealership, they're like $80 / pair on ebay :-\.

[JimmyNoShow]

keep petcock in on position. Fuel should not have to be removed. that is what the petcock is for.
I had my plastics on and off twice today and tank on and off 4 times.

keep petcock in on position. Fuel should not have to be removed. that is what the petcock is for.
I had my plastics on and off twice today and tank on and off 4 times.

Bikes are some work . Antifreeze your funny

[Shaded02]

why has no one yet mentioned spark plug wire to spark plug cap connection when i bought mine it ran on 3 maybe 2 cylinders when i found out the "boot"/cap was a completely separate part i checked all of them and sure PO was an idiot and tried hooking them up like speaker wire so i clipped the ends of the wire screwed them onto the caps and it idled perfectly when it was warm but you can get a set of dc1-2 dyna performance coils and a set of wires on ebay for $140

[hardlydangerous]

Plug caps usually fail before the wires do.
The wires will corrode if moisture is allowed in.
the plug caps have built in resistors, remove the caps and test them with an ohm meter and make sure they are within specs. replace is not.
Trim off the ends of the wires before you re attach the plug caps. Usually 3/8" or so. Be sure to add a dab of dielectric grease to the ends of the wires before you thread the caps back on. Its often very hard to get them on, so i like to mark them 1/2" up on the wire so I know when they are threaded on all the way.

[Syndacate]

So today me and a friend got around to ripping it apart.

I was hoping it was just the plugs, thinking one got fouled up when the spark plug wire popped off of the plug. It was definitely looking like this was the issue as it seemed the last person who changed the plugs didn't screw 3 of them in, and there were 2 different spark plugs used. My hopes were quickly shot down, though, when none of the spark plugs looked horrible, especially on cyl 1, where I expected it to.

New spark plugs in, runs exactly the same as it did .

I'm really ****y about this b/c I need to sell this bike ASAP but it's hard as **** to sell a bike that's not running right for a decent price, even if it's just a small issue like this. I kind of just want to buy a wire/coil set from somebody on here but I feel like that's just throwing money at the issue.

I guess the next step is to borrow my friend's timing light, and latch it onto one of the wires, see if I can find a particular plug wire that's not getting juice or something. It's able to run and it looks like it's a wasted spark ignition system....so in theory it couldn't be running if an entire coil was bad, as it would reduce it down to two cylinders. Not entirely sure where to go if everything looks good there..possibly the juice going to the coils?

Anybody have any input?

EDIT:
I guess I shouldn't say "impossible" - it could be an alternating mis-fire between two different cylinders if the coil is broken in such a way that it's having trouble reaching a high enough voltage to arc the plug :-\

[5forty2]

Really? Mucked up carbs caused a cylinder not to fire?

Ummm, yeah! How is it supposed to fire if it's not getting enough/any fuel?

Also, the oil for the motor and cooler is the same oil.

[Syndacate]

Ummm, yeah! How is it supposed to fire if it's not getting enough/any fuel?

Also, the oil for the motor and cooler is the same oil.

I'm thinking it's not a fuel starvation issue.

It's popping sometimes when I let go of the throttle, that points to an ignition issue, unburnt fuel in the pipe. Gotta figure out why the hell it's not firing on that cylinder . Kinda stuck....blah....

[Kreylyn]

I'm thinking it's not a fuel starvation issue.

It's popping sometimes when I let go of the throttle, that points to an ignition issue, unburnt fuel in the pipe. Gotta figure out why the hell it's not firing on that cylinder . Kinda stuck....blah....

The real problem... you don't know why the bike is not running right and your grasping at straws for "fixes" and they are not working, or resolving the issue. This causes frustration and unclear thinking... (Been a victim to it myself... )

You need to take specific... methodical steps... to eliminate possible issues. Right now you have no idea if it's fuel, spark, or even an air issue. Take steps to narrow it down.

Fuel: (the most likely cause of most running issues). Clean the carbs. Clean them seriuosly well, use a carb dip, disassembly them entirely, soak them at least 24 hours when you do the dip, use compressed air and carb cleaner spray afterwards to finish cleaning them and dry them out. You have to make sure you remove the a/f screws as part of this. After the dip, use the cleaner through the passages followed by compressed air. Replace your fuel lines if they are hardened, or not real fuel line (vacuum line is a problem as it will collapse on it's self and slow the fuel flow). Put all the parts back in, make sure you have the jets in the right place (if you have variable sized jets in your bike), make sure the a/f screws are in right, and make sure all the rubber put back in is in good condition. Bench sync the carbs.

Air: check for vacuum or air leaks. Make sure the orings on the carb to engine boots are in good condition. Replace if they are flattened. Make sure the boots have no cracks. Replace if damaged. Make sure the airbox boots are sealed to the airbox. Re-seal them with gasket sealer if they are not. Make sure the airbox has no holes, the drain tube is in good shape and plugged off, and make sure the air filter is OEM filter. If not, replace with OEM. Check compression on each cylinder to make sure the engine is pulling air through. A massive difference in compression between 2 cylinders can't be adjusted out with a carb sync.

Spark: Use known good/new plugs. Inspect the plug wires and plug caps. If damaged, replace it. Wires should be soft/flexable over the entire length. You can test the coils to make sure they are working right, but if it's only 1 cylinder your having an issue on... probably not a coil issue.

Tests to do after all that if it still won't run right...

If you think it's a spark issue on a single plug, swap the wires from the same coil. Did the problem follow? (if no, it's not electrical). If yes, look further at that specific plug wire and it's connections all the way to the coil.

If no change, and it is still the same cylinder causing the issue... It's probably a fuel issue.

Krey