91 600 starting issues; getting ready for spring

[XXWoodmanXX]

Well, I got the airbox off and I just recently rebuilt the petcock (damaged O-ring was leaking gas out the knob), and was looking to turn my bike over. I tried several times, but she just wouldn't turn over, so I used some starter spray, and she fired right up, revved, and eventually sputtered out.

Is the removed airbox the culprit? She ran good back in the fall before I put her away and put some Sta-bil in the fuel. I cleaned the tank out and am running some new fuel, with a slight dash of Seafoam in it.

I used to be real good with these, but I forget just how important a role the airbox(w/ stock filter) plays. Are these REALLY that sensitive without the airbox on????

[Wild-Bill]

The bike won't run well at all without the airbox. Put it back on.

[92xjunker]

did you check the petcock for proper operation? did you prime first?

[XXWoodmanXX]

Yeah, I made sure I was in the prime position. Took me awhile to remember the positions for it. lol

I even went as far as replacing the fuel lines with clear fuel lines so that I see the fuel getting down to the bowls.

Tomorrow, I will pull the plugs, clean or replace them, and get the airbox back on. Will see what that turns up. Thx

[Wild-Bill]

Don't worry about the plugs. Put that airbox back on, plug the petcock vacuum line and try starting the bike. You've got enough fuel in the bowls to see if the bike's going to start. Then if you feel like messing around with plugs, knock yourself out. More likely you'll feel like buttoning her back up and going for a ride to clean those plugs off.

[XXWoodmanXX]

I like your thinking, sir! Especially since they pushed the rain predicted tomorrow back till early Monday, and it's going to be close to 60F. *big thumbs up*

[Wild-Bill]

It went over 70 today and I needed to take something to my son who was out camping with the Boy Scouts. Better believe I was on the bike!

We've got thunderstorms rolling in now and it's supposed to rain all day tomorrow. Gotta enjoy the nice weather while you've got it.

[XXWoodmanXX]

Ok, got some tuning to do I guess. She'd fire up and I can rev it, and she'd hang, then fal down around 2500-3000rpm, but if I dialed the idle down any, it would eventually fall off and stall. Think I am running too lean.

*sigh* And since I have a friend using my carb tool and busted it, I just had to buy another online. Ugh. Oh well. Beats pulling the carbs.

[Wild-Bill]

Sorry but it sounds like you're pulling the carbs anyway. Your symptoms indicate a clogged idle circuit or a bad vacuum leak. Most common place for that bad of a vacuum leak is the boots connecting the carbs to the airbox. If one or more of them isn't fully seated on the carbs then that would cause your problems. Easiest way to make sure those are right is to pull the carbs, reseat the airbox onto the carbs and then install them together. If that doesn't solve the problem then it's going to be time to clean the carbs.

[XXWoodmanXX]

Think I might pull them, yeah. Been about 9 months since I rebuilt them, and its basically sat up until yesterday. BTW, they have not been syncd, and I haven't gotten to the mixture screws oncarbs 2 & 3. If they are like the outside carbs, then the screws are approx. 1.5 turns out.

[Wild-Bill]

Pull them. Set all 4 mixture screws to 2.5 turns out, bench sync, reinstall (put the airbox on first) and vacuum sync. If the trouble goes away then you're OK and you got lucky. You might be able to get them clean by running a tank full with half a can of Seafoam. If not then it's time to clean them again. 9 months of sitting isn't good for those carbs.

[arsenic]

Bill, it's not half a can in a full tank. This is the second time I've said that. Read the directions and do what it says to do. Dumping a half a can in a tank doesn't make it better.

[Wild-Bill]

Seafoam recommends 2oz/gallon and comes in a 16oz bottle.
The math says that half a can (8oz) is the proper amount to treat 4 gallons of gas.
The Katana 600's tank holds about 4.5 gallons of fuel.
Unless you're suggesting that people should be measuring out 9oz of seafoam (9/16 of a can) to put in the tank, half a can is close enough.



Don't be a twit.

[arsenic]

A 1/4 of a can works a lot better. But go ahead and dump 1/2 a can in, it's not my bike, I don't care.

[XXWoodmanXX]

Pull them. Set all 4 mixture screws to 2.5 turns out, bench sync, reinstall (put the airbox on first) and vacuum sync. If the trouble goes away then you're OK and you got lucky. You might be able to get them clean by running a tank full with half a can of Seafoam. If not then it's time to clean them again. 9 months of sitting isn't good for those carbs.

Gotcha. Weather's gonna be pretty decent, so I've got a good bit of time mapped out to be in the garage this week. Thx.