At my wits end

[JamieK]

I was also wondering if it could be something to do with the throttle cable?? It has to be something that affects all 4 carbs so it really does kind of limit what the issue could be...is the choke stuck partially open or closed?

[okbandit]

Hey Waldron, before you do all that, if you send them to me I will get them going for you.  I have three b-12's and I have been through this stuff many times.  No charge, except you pay the shipping both ways.   If I can't fix them, I'll pay to ship them back.  For some strange reason, I actually like this stuff (problems with engines and machines).

[pmackie]

Now there's an impressive offer - free labour from an experienced member who will even cover some of the cost if he can't fix it...Wow, okbandit, you're the man!!

Hey Waldron. Most of the guys here are pretty happy with their Bandits and want to see you have a successful experience with your bike, because they're great in my opinion. Stick with it a little longer, and you may be pleased in the end.

[Waldron]

Here's what I did:

http://www.tinynet.us/bandit/problems/

[pmackie]

Your pics all look good. I don't see anything amiss (but your carbs are different than my 600's). I hope one of the 1200 guys can spot something.

But one thing occurred to me. Have you checked the TPS unit bolted to the side of the carb? It's possible it got bumped and moved while you were working on the carbs. It's worth checking. There are instructions on the board here - http://forums.banditalley.net/viewtopic.php?t=3447&start=0&postdays=0&postorder=asc&highlight

Also...maybe see if it runs any better with the air filter removed. Your comment about the pint of fluid in the airbox has me a bit concerned.

It's possible the dirty carb issue has got you off the real problem. So confirm a few basics:
1. Battery state - should measure 13.2-13.4 volts if it's in good shape. Make sure it's up to charge.
2. Check all the plug to cap and cap to wire connections on the plug caps, as well as coil connections.
3. Make sure the throttle cable is pulling the butterflys all the way open.

I hear your frustration...but remember your training...with the correct spark timing, approximately correct fuel/ratio and enough compression, by the laws of physics, it HAS to run (properly).

[Waldron]

The thing to keep in mind here is the bike ran FANTASTICALLY! Really...carbureted without a problem until I took them apart. So things like the air filter or the coils CAN'T possibly be the problem. It's the same air filter that was in it when it ran GREAT. They're the same coils that were in there when it ran GREAT - they didn't both go bad at the same time, and instantaneously. The sequence:

It ran GREAT.
It clogged a pilot jet.
I took it apart and cleaned it.
It ran VERY VERY POORLY.

[Red01]

Rule #1 of troubleshooting: Never rule out those things you think it can't be because they were fine a few minutes ago - or just replaced.

I can't remember how many times my violation of this rule has caused me hours of extra work & frustration because the problem was what I thought it could not be.

[02blue]

I had similar performance problems after a shop re-worked my jets.  I took it back and they fixed it by cutting a portion of the air box away that was sucking into the carbs under throttle.  Not sure if you have an air box or pods, but this could be a cause.

[vwkaferman]

I had similar performance problems after a shop re-worked my jets.  I took it back and they fixed it by cutting a portion of the air box away that was sucking into the carbs under throttle.  Not sure if you have an air box or pods, but this could be a cause.

Pssst, that was back in August 2007. ;)

James

[CWO4GUNNER]

Although you can use some deductive reasoning to locate a problem quickly based on when symptoms occurred, i.e (it was running fine before I cleaned the air filter), you cannot rule out step by step deductive trouble shooting which I haven't seen posted on this thread, but mostly hop around attempts at fixes without proofing any of the basic trouble shooting theories. When I have these problems a put on my emotional blinders and work systematically through combustion therory and fault isolation until the gremlin is found.

[Rocketjock]

Then there's air leaks. Older, cracked rubbers can do the trick. OK till you remove them and then the air leaks begin.

[Ranger]

I'm placing bets:
1. Trashed petcock
2. Vacuum leak
3. Cracked and brittle (inside) fuel line

any takers?

[Rocketjock]

I dunno, Ranger. Is that your poker face?

[Ranger]

I dunno, Ranger. Is that your poker face?

Yeah, a brief moment of sobriety 

[Blade]

Guys, I am totally stumped.  I'm begging; I'm on my knees...PLEASE HELP ME!

Ok, me:
   15 years as an automotive tech, 3 years  as a motorcycle tech. But I haven't worked "in the field" for about 10 years. I'm rusty, but I should  know my arse from my elbow.

The bike:
   2002 GSF1200S K2. About 4600 miles; I bought it about 3 months ago. From all indications, the bike sat for about 2 years or so, possibly after being dumped. There is not one single thing on this bike that isn't factory stock.

The history:
   When I first got the bike, I switched to reserve (on the ride home). Right away, it started running poorly; it felt like a pilot jet was clogged (it would lose a cylinder at cruise, and get it back under throttle). It got better after I filled up and switched back to "On", so I kept riding it. It started running poorly again a few days later, this time it wasn't just one cylinder...it was across the board. I was going to pull the carbs then, but I saw the airbox drain in the manual, so I pulled the plug. There was about a pint of liquid in the airbox; after I drained it, the bike ran well again. A few days later, back to a clogged pilot. This time I pulled the carbs and cleaned them. I know I should have flushed the fuel tank, but the bike ran well (fantastically, actually), and I put it off. Weeks later (and after an 800-mile trip), I brain-spasmed and had to switch to "Reserve". At first it was no problem, but after a few days it started running like a pilot jet was clogged again. I took the carbs out and cleaned them, and it hasn't run right since. In looking for the problem, I noticed that there was water in the tank, so I flushed the tank, took the petcock apart and cleaned it out, and pulled the carbs and cleaned them (again)...THOROUGHLY! I figured I had found the problem, but I was wrong...it still runs the same.

The problem:
   When I start it, it seems "normal" enough. But when I rev it, it just won't go over 3000 rpm...if I give it more throttle, it dies. If I give it full choke I can get it as high as 5000 rpm, but that's it. If I try to drive it around the block, it has power until about 1/4 throttle, and then it falls on its face. It did this before and after I cleaned the water out.

Troubleshooting:
   I had a set of plugs I wanted to put in it anyway, so I went ahead and did that. The old ones were a bit on the dark side, but nothing terrible (pretty normal, actually). The new plugs are gapped to .026". No difference. After it ran for a minute or two, I touched each exhaust pipe lightly with a wet rag...all 4 are hot. I ran it with the fuel tank lid open. No difference. I put a tube on the drain of the #1 carb and drained off some fuel...it looks great, clean and dry. I blew through the overflow hose and the vent line for the fuel tank, and there were no obstructions. The vent lines for the carbs are open and un-kinked. I held the tank over a bucket and set the petcock to "Prime" and plenty of fuel flowed. The floats are set to 13mm. The pilot screws were 2 1/2 turns out; I bumped them up to 2 3/4 turns to richen it up slightly. The fuel in the tank is now 2 days old. I pulled the vacuum line that goes from the #4 carb to the petcock and PAIR valve, sucked on it and then covered it with my tongue; it holds vacuum for more than a minute. When I was putting the carbs together, I blew into the fuel line and rocked the carbs to shut and open the needles; when they shut, no air flowed. Nothing drips or runs. All 4 slides move to the top of their travel freely with a fingertip, and return easily as well. All jets are open; I sighted through all of them. With the petcock in "Prime", nothing overflows, and the airbox stays dry. The air filter is a little dirty, but nothing that could explain this behavior. Every passage that I sprayed carb cleaner into did the same thing on all 4 carbs.

Thoughts:
 I figure it has to be something I did to the carbs...it ran really well until then (except for the clogged pilot jet). The rest of the fuel system seems fine, the ignition system seems fine...all signs seem to point to the needle circuit. I had some question about which way the needle jet went in, but it sure seems like it only goes one way. I have the main jet (#100) on the emulsion tube, and the starter jet (#60) in the hole in line with it. The pilot jet is in the offset hole.

   At this point, I'm totally stumped.  If I had the cash, I'd take it to a shop (hang the embarrassment), but I just don't have it right now. What I DO have is the wolds largest paperweight, and summer is passing me by. Again, I'm begging...whatever it takes, I'll do. Go ahead and brainstorm; you can't insult my intelligence (at this point, I don't think I have any left). HELP!

Based on this post and the one with pictures, this is what I see:

1. I saw one thing wrong in the pictures, the air fuel screws should be 3 turns out.
2. Also you did not say what your float level is. Should be 13mm just as the float touches the needle.
3. If the bike set for a long time, I would venture to say that a lot of varnish has built up and everthing may need to be boiled out with a good carb cleaner and fuel hoses replaced.
The carbs looked clean, but were all the jets clear? The stock pilot jet is a 15 and that is a very small hole.