Dropped a cylinder

[scfshon]

Hi, new member here. I have a 2001 Bandit 1200S, 23,000 miles on it that I picked up a couple months ago. Is there any way to know if it has a jet kit in it? It does have a Yoshimura pipe on it but I don't know if that necessarily means it has any jetting changes.

The real reason for my post is I was running her through the gears last night on my way home from town and in 3rd at about 8,500 RPM I dropped the number three cylinder. (The reason I know I lost #3 is because when I got home that exhaust header was noticably cooler than the others) There was no clunk, no noise, and the motor continued to run smooth afterwards but when I rolled on the throttle it seemed to cut out again. I started it this morning just to doublecheck if it was running on three or four cylinders and all exhaust headers were equally hot.

Of course, my main concern is that I didn't do major damage to the engine and I don't know if I have given enough info here for someone to have any ideas what could have happened.

[pmackie]

Is there any way to know if it has a jet kit in it?

Check out this thread:

http://forums.banditalley.net/index.php?topic=10813.msg86800#msg86800

[Red01]

From your description, it doesn't sound like any damage occurred.  If you dropped #3 one day and the next day all is well, my guess is something clogged a jet and managed to clear itself.  Might not be a bad idea to disassemble the carbs and give 'em a good cleaning and inspection.

[scfshon]

Thanks for the reply, sir. Would you recommend that a person who isn't very experienced in working on carbs chew into this?  I don't have one yet, but is the Bandit repair manual detailed enough to walk me through it? I had a Yamaha Fazer I tried working on the carbs myself and the instructions were like:
 
Step One. Remove carbs. 
Step two. Clean them out. 
Step three. Replace.
 
Um...Hello!? 

I'm the type of person who knows just enough about a lot of things to be dangerous, and after most repair jobs I have done in the past I have parts left over.. 
 

[scfshon]

One thing to add; I took it out for a short ride yesterday and when I took it above idle I lost the third cylinder again so it would appear as if something is restricting flow or spark to that cylinder. I did order new plugs this morning but am dubious about it being that easy of a fix.

[rider123]

9 times out of ten it's usually a wonky spark plug. For fun replace the number 3 cylinder plug with number 4(or 1 or 2) and see if you have the same problem. If so then you should look to either water rusting the leads or some other simple electrical problem. It's very rare that a carb stops totally functioning. It would be a real bummer if you take aapart the carbs for 12 hours and all it is is a 30 sec spark plug change. Since you got it used who knows when the plugs were changed, if ever. Try the simple stuff first.

[pmackie]

Try the simple stuff first.

Good advice... I would start with (after the plugs)
1. Check plug wires and caps for cracks and damage
2. Drain each carb bowl - there is a drain you can get at, AND put the petcock on PRIME and make sure you get flow through each carb bowl.
3. Check the air filter, change if necessary.

However, it IS possible it is a carb problem. OK at idle, but not with some throttle. You may want to put some seafoam or techron through it first, but pulling the carbs isn't TOO difficult. The hardest part is usually reconnecting the throttle cables, which is NOT explained in most manuals.

It is best to take some pictures as you take things apart for the first time, so you know where hoses, etc go.

[scfshon]

Thanks to all for your advice and guidance. One other thing to note is that when I start the bike and idle it in the garage it smells very gassy and rich. That seems like a good sign to me that it's spark plug related. 

Shon

[longislandbandit99]

Definitely start easy and work to difficult.  Put new plugs in it and make sure they are torqued properly.  Find a torque wrench and learn how to use it.

Check the wires for something dumb like a loose connection.  Just because it has an aftermarket pipe doesn't mean it was jetted.  The bike has a ton of miles on it, you may want to just take it to a mechanic and have him do a slight overhaul.  The valves need to be adjusted I'm sure, the carbs should be cleaned out properly with new float needles and stuff.  Without asking the previous owner what kind of maintenance he had done you'd be smart to just have it done.  Do you trust the person you bought it from?  Do you know them?  Ask them what scheduled maintenance they had performed and when.  It sounds to me like bad gas gunked up the #3 carb and the needle in the float is stuck closed.  But who knows.  Usually carb problems show their ugly face at idle when the really small inlet ports and orifices are used.  At open throttle the bike should run well since you are using main jets and orifices.  The carbs could be out of sync as well.

[Dink_1170]

Your symptoms point to the carbs, most likely the emulsion tubes above the main jets. does the fuel petcock draw vacuum off #3 from the left of the bike as seated, if it does it is very likely the fuel petcock, split diaphram allowing excess fuel to that carb. Plug colour should tell you if that is the case as the plug at the appropriate plug will be a lot darker.

Dink

[Red01]

does the fuel petcock draw vacuum off #3 from the left of the bike as seated,

It should draw petcock vacuum off #4.  While any carb would work, #4 is the one the factory chose.  The other three just cap off that vacuum port.