Quote from: mustangGT90210 on January 29, 2013, 10:48:31 AM
Sounds like it. To check the stuff for a vacuum leak, I get the carb cleaner in a can and spray that, right?

Hell no ... atleast not unless you're wanting to start a fire.
WD40 preferably the squeeze spray kind and not the pressureised can ... though that also is pretty safe.

You're vacuum line runs to the frame petcock.

Hanging idle = lean. It can be lean wihtout having a vacuum leak, or can be the result of a vacuum leak.

Adidas - that cat buddha is one unholy bastage.

Cool.
Buddha

...Alright, anything volatile you use to check for vacuum leaks is 'dangerous'... but that is also why it works.  Brake cleaner is a little 'safer' than carb cleaner... and WD40 is 'safer' than both of those.  However, they are also less effective in detecting a leak as you go down.  Heck, I've also heard of people using an unlit propane torch to find leaks...

Regardless, know that any checking like this carries danger.  Also remember that carb cleaner and brake cleaner aren't nice to rubber or plastics, so it is always a good idea to try WD40 first, anyway... But if that doesn't work, don't rule out a leak.

- Bboy

Edit: I'm waiting for sledge to reply to tell us the way to do it by the book, using smoke in the vacuum circuit or something like they do at a shop with the right machine...  Just waiting for it because I do appreciate the balance his comments provide.

Also, the unlit propane torch sounds more dangerous than it is... you just don't want to get a pool of it in some nook or cranny and then....

Quote from: The Buddha on January 29, 2013, 08:45:23 PM

Quote from: mustangGT90210 on January 29, 2013, 10:48:31 AM
Sounds like it. To check the stuff for a vacuum leak, I get the carb cleaner in a can and spray that, right?

Hell no ... atleast not unless you're wanting to start a fire.
WD40 preferably the squeeze spray kind and not the pressureised can ... though that also is pretty safe.

You're vacuum line runs to the frame petcock.

Hanging idle = lean. It can be lean wihtout having a vacuum leak, or can be the result of a vacuum leak.

Adidas - that cat buddha is one unholy bastage.

Cool.
Buddha

Looks like I'll definately be keeping the hose close while I check this today lol. And I don't think the bike is running lean, the plugs are a brownish color with a tiny bit of white. That and the hang up is sporadic. The bike will run for days without, then it comes back with a vengeance, and it happens way more when the bike is warm. I thought a lean problem would be most noticeable when the bike is cold? It'll rev great, and come back down just as good until it's up to temp (when it wants to hang... it's inconsistent too often!)

So last night, problem re-surfaced big time. Left plug is black as night, and when I really get on it the bike just makes the same noises as when you try to give it gas when it's on empty, that real low, struggle sound. The bike will cruise fine, but it's got no balls as soon as I want to get up and go.

I think it's flooding the left cylinder with fuel when I lay into the throttle. This would also make me want to check the float height, correct? I have yet to do that while I've owned this bike. I'll also be checking the operation of the choke later today, may have to bend the lever on the carb a little bit because it does seem to always rest just slightly on the plunger for the left as well

If it suddenly comes and goes it could be electrical.

Try swapping the plugs - see if problem moves to the other side
Check the coil wiring - maybe loose wire. maybe spark plug cap not on good. Those do unscrew from the coil and the caps unscrew from the wire.
Possible an ignition pickup is going bad - intermittent due to heat or vibration.
Possible the ICU is going bad from heat or vibration.

Check all connections for those things. Unplug them. Spray come contact cleaner. Plug back in. if a connection looks bad, plug & unplug a few times to wipe the contact clean.

I had a plug go bad once. Engine ran then sudden;t loss of power. Then suddenly it came back. On and off. Plug had some internal crack that opened & closed making the left cylinder work then go dead. Then work. The go dead.

I feel if it was a carb issue, the problem would face in and out rather than sudden;t cut in and out.

I discovered mine was the plug when I swapped the plugs when putting them back in and the problem went to the right cylinder.

The only reason it doesn't seem electrical in my mind is because it's been a progression. One of the cylinders - presumably the left one, would not fire when I started it, but give it some gas and then it would come alive as well. Last night is the first time it hasn't seemed to have come back.

I'm about to go out there now, clean the plugs, check the float height, and adjust the choke. I'm really hoping the choke is just out enough that it's dumping way too much fuel in. I hate electrical work lol I'm wishing and hoping it's a mechanical thing!

Have you checked the choke (actually "low speed circuit" not choke)to make sure it is closing fully when you push the lever all the way forward? I found out early on this engine will do all kinds of weird stuff if the choke is not fully de-activated when the engine is warmed up
running too fast at idle is for sure one thing that it might do. I was used to riding fuel injection motorcycles and forgot all about this "choke" stuff! (DOH!) I left the house for a ride, the bike was running perfectly, 15 minutes later the idle was all over the place at a stoplight. I rode straight home, all freaked out over it cuz I had just been through a carb problem...the left hand carb needle valve/seat got some trash stuck in it.  Gas flooded the cylinder and ran out of the carb throat while the bike was just sitting in the driveway. After cleaning the carbs and doing a "static" carb synch, the engine was running incredibly smooth! Then the choke thing happened on the first post-repair ride. I sure was relieved when I realized what it was,,DOH!

Anyway, something about what you are going through sounds awfully damn familiar! Curious to hear what it is.

Quote from: mustangGT90210 on January 29, 2013, 10:34:45 AM

Which vacuum line are you talking about? I've still gotta check the carb boots for leaks as well. This bike has never really liked to idle. Requires constant adjustment, like every couple rides. It always fluctuates, stalls when I get hard on the brakes, and the weird part of it - I've tried setting the idle the proper way, but then as soon as I give it throttle it'll hang... a lot. But if I leave the idle low enough it'll idle badly but the revs won't hang up.

And by hang up I mean it'll sit at what feels like 4-5k rpm for 30 seconds and then come down. And go back up there again

We shall see! I'm hoping it's that simple. I didn't get out there to adjust it the clutch lever the other day because I was just too tired to get off the couch before class and tear into it. It'll be getting much needed attention tomorrow evening. The guy that filled in with me at the drag strip last weekend happens to be a motorcycle engine builder by trade, and drag races a realllllly nice GSX-R. So hopefully we'll get this all figured out!

Alright well I have kind of an update. I've removed my broken choke cable, choke operation is once again proper. I need to get a new rubber hose for the float height, seem to have lost my old one. Took a thermal gun to the exhaust pipes right as they were leaving the head, and it tells a big story. Right side (good one) was up to about 400 in exhaust temp in about 10 seconds it felt like. Left side maxed at around 300 during the same time frame.

And I'm shooting both orange and blue flames about 8" out my exhaust pipe when this thing backfires, which is does A LOT right now. And I found an air leak as well, it's on the right side carb boot, left side boot didn't yield any results to carb cleaner, but we'll see.

Now that sounds pretty cool, shooting flames out the back, for some reason I dont think you would pass emissions here in AZ tho lol.

No emissions in Florida 

Did a little more work today. Went out there, tore it all down, gave the carbs a quick spray with some cleaner (had 'em open, may as well even though they were pretty clean). Got the float height JUUUUUST right using the U-bend method. Less backfiring.

Brought it back, cleaned the plugs - more power, more backfire. I don't know about flames this time lol

Now while it cools, what should I look for next? I want to do that spark plug boot thing where you re-do wires but I have no idea where the stuff separates and I don't wanna destroy my entire wire/boot out of ignorance. I'm getting back close to stock power, and if I rev it slowly, the revs will climb well. Floor it and it bogs down a bit.

And finally... if my valves were waaaay tight, could they cause this?

Update:

I've disconnected every electrical connector, and used contact cleaner for each, then re-connected. Plugs were cleaned and re-gapped again. Tore open the top part of the carbs also just for shits and giggles, and this is where the fun starts. My left side diaphram has about a 1 inch tear down where it meets up with the plastic part for the spring and needle. But I also slipped a little when taking the cover off the top, so I don't know if I caused this just now, or if it was there before. Regardless I need a new one. So would that tear in the diaphram cause some of the symptoms I was having, or what? I'm not even really sure what it does to be honest

You did a double post! MISTER - it is time to discipline the sheep.

Does a carb even work with the diaphragm torn?

I doubt you tore it opening it up. Either it did it on its own or a cat got in there and scratched it.

Quote from: jestercinti on January 11, 2013, 01:30:40 PM
You need 3 things to make an internal combustion engine run.

Spark
Compression
Correct fuel/air mixture (carbs, injection).

Start with spark.  Is it strong, or weak?  If none, swap coils and plugs and see if the problem follows.
If it's not the spark, coils, or ignition...move to the carbs.  One side may be dirty or not synched.  Baltimore GS has a nice video of synching carbs.
Compression is the last thing...but most likely it's fuel or ignition.

Excellent advice, especially in the order listed. Do what he says. 

Just ordered a new diaphragm for $25  from Suzuki! How do I go about removing the old one? I didn't know they could be separated

Quote from: mustangGT90210 on February 07, 2013, 11:13:16 AM
Just ordered a new diaphragm for $25  from Suzuki! How do I go about removing the old one? I didn't know they could be separated

If you're referring to the ones on the carb slides, they go on and off just like an o-ring... stretch them over the lip and they hold themselves in place.

Side question for people with more experience, is this something that you should replace as a pair?

If I had the extra money I'd pony up for the pair. Broke college student I am can't do that lol.

Thanks very much on the how to on install! Last thing I want to do is break the $60 slide.


And finally, I have a good update to make to this thread, just save the redneck jokes for later  I took some black RTV instant gasket maker, and smeared it all over the rip in the trouble diaphragm. Let it cure on there, then reassembled everything. This bike runs great. Still has a leak somewhere (or is now making the proper noises and I think their wrong cause I haven't heard them) but the bike pulls great in higher revs, the idle is steady, and also I don't have a hanging idle problem anymore!!

What, no duct tape?

(Sad to say, no cat pictures this time. Only cat + duct tape pictures I found were of animal cruelty.    )

Quote from: adidasguy on February 07, 2013, 09:04:02 PM
What, no duct tape?

(Sad to say, no cat pictures this time. Only cat + duct tape pictures I found were of animal cruelty.    )

I shouldn't have looked that up on google images

I did find a pretty funny one though, how to punish a kitty for eating forbidden foods...



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Haha very nice. He bested you adidas.