93 600 question

[imprtkid04]

Ok, so i think i already know what my issue is, however id just like to possibly confirm it.

I got this bike about a month ago, it was wrecked and now im putting it back together slowly. I got to the point of starting it last week and it starts! However i do have to open the throttle (all the way) to start it, also after it starts up and it gets warm it stops responding to the throttle. (you cant let off the throttle, or it stalls out) I can open the throttle all the way, and the bike will only stay at about 1000 rpm. I know that the carbs need cleaning, but would this be the only problem?

I had a fuel leak from one of the float bowls, i ended up replacing the o-rings to stop the leak and it did. Thats as far as i felt comfertable getting into the carbs. Basicly id just like to make sure that its in fact the carbs before i drop 2-300, not something as simple as the drain plug at the bottem of the air box (which i need to check this week).

Thanks for any input.

[Newbie2it]

Gasoline engines require three things to function. Air, Fuel and spark. By your own admission twice, you stated that the bike will only start and/or stay running in a WOT situation. Basically your saying the bike will only be able to run, barely at that, When maximum air intake is afforded. Or no spark, but you know you got spark since it will run WOT.

More air intake (WOT) means theres too much fuel delivered to allow proper combustion. So that means you have two possible causes.

1. Air intake thats nearly blocked but relieved via a WOT.
2. Too much fuel allowed into the system for the normal combustion process.

Now, I am hedging on #2 as the problem. More than likely fuel levels set too high or floats that are sticking. Cleaning the carbs are all good, However, somethings causing you to get too much fuel. You know your getting enough fuel since adding more air to the mix is helping. However, each case might be a little different. What do your plugs look like? They alone will tell you a lot about whats going on with your motor since they are the ones responsible for doing what it does best! You will need to delve a little into the carbs to adjust the floats (covered here on Katriders) and once your there, you can do the extra cleaning you want to do. Take it a step at a time tho.

Give us a little more info and BTW, don't be afraid of the scarey carbs, they aren't all that bad to figure out *IF* you take them at your own learning pace.

No need to drop 2-300 on something we all can help you through.

[BigDub]

Unless you make 300 a day, I'de do it myself. It's pretty simple to do with a regular set of wrenchs, sockets, long screw drivers, and a pair of vise grips.

It's something you need to know how to do.



The carb rebuild is pretty easy, if you know how to use an impact screw driver. It's a screw driver that you hit the butt with a hammer and you push pressure while the driver unscrews your screw that you're in. It's used to unscrew screws that were installed with a thread locking agent(glue.)

I've made one out of the new hex screw driver bits by locking it at a 90 degree angle in the jaws of a vise grip and then putting my body weight down over the screw and using the length of the vise grips to turn out the screw(initially) with my weight bearing down into the screw. That's a little cheaper than buying an impact driver unless you have a good pawn shop nearby.

The long and the short of a carb rebuild is match up the orings with the right size from the plumbing oring section of lowe's, home depot, ace hardware, or any other plumbing supply store. replace the worn out orings as you dissassemble, inspect, clean, blow-out with can of air(computer ketboard cleaner from Staple's, Walmart, office Depot.)

The equipment to do a carb rebuild in the absence of a major part being damaged beyond normal rebuild costs less than 20 dollars. The time you give up to rebuild your set of carbs is less each time you do it but, probably will initially take you anywhere between 2-8 hours.

The hardest parts for me were getting the screws to break free. The screws that were installed with a locking agent/glue. The other hard part was getting a good leak free seal with the diaphragms and the airbox. Just leave out the diapragms for a good hour or so to give them a chance to reform to their original shape(especially if you have one pinched leaving an air/vacuum leak which will cause your bike to run funny.)

If you follow the instructions from Carbs 101 which is located at the link below, you'll do just fine to find any issues with your carbs along the instruction pathway.

Carbs 101:

http://katriders.com/vb/showthread.php?t=63557

Allow a whole night or day shift in case you run long or run into any problems left by a previous owner/carb rebuilder.


I highly recommend developing a strong grasp of the visual synchronization process. There are other posters who have done this as well as myself with excellent results.
I did mine by setting the 3rd carb blow-by hole/pilot circuit hole to the butterfly to the point where I coul just barely see it as a slit the shape of a cat eye. Then try to match the next carb to it to the same point. The key is balancing all the carb pilot jet holes on all 4 carbs to the same junction point with respect to the butterfly valves. Ultimately the idle adjust screw will leave these all at the proper point to idle the bike at approx 1350 RPM. As long as you have great close up vision and you visually synch those carbs to the same junction I just referred to and your carb routings are crystal clear and you have an excellent vacuum seal, in the absence of other issues, your bike will sing like a DIVA!


Just do it! Go for it and Good luck w!

[imprtkid04]

Honestly ive been workin on so much other stuff i havnt checked the plugs. Ill do that first thing wednesday when im off work and update this thread with what i find.

Edit, Ive read over carbs 101 actualy atleast 3-4 times. Ive also read over my manual that i printed from this site. I still dont fully understand all of it and thats why im hesitent on tearing the carbs down and then putting them back together. I mean i can do the tear down and put back together, but the patience and the settings is what gets to me. I guess this week ill dive head first into it, whats the worst that will happen? I have to take the carbs down to the dealer and have them finish up and ill have to eat the outragious costs.

[BigDub]

There's no telling what got dislodged in a wreck that's causing it to run rough. probably a float still stuck. Plus maybe some dirt. a couple of times when my floats got stuck on separate occasions, i just popped off the bottoms and tapped em up and down. that's a fast thing to do as far as a quick check is concerned. But once you've disassembled those carbs one time all the way, you'll wish you just did it from the start rather than taking them off and on until you actually end up going through the whole process

I highly suggest you just bite the bullet and get on with a complete step by step rebuild.
Just read Carbs 101 and knock it out. it really won't take you that long.