Need Fuel system help

[bconley]

So, I bought my 96 Katana 600 about a month ago. The guy told me when I got it that the fuel petcock is in the on position when it faces the rear of the bike, off when facing the ground, and reserve when facing forward. This goes against what the manual says, and what the fairing says. Here are my questions.

1. So for the last month I've been riding with the petcock facing the rear. I haven't really had any problems with it, except for some erratic idles and the engine stalls occasionally, but this is only after the bike has been in rain (I live in FL, so...yeah). Is this caused by water in my fuel line, or air intake?

2. I put the petcock in the down position for the first time today, as per suggestion by a mechanic. It was fine for 2 miles or so, then I started to loose power and eventually the bike stall. Could it be that the last owner changed the settings of the petcock so that it IS in the On position facing rear, or is it a problem with my vacuum.

I'd really appreciate the help.

Thanks

[ICEG]

ur bowls were filled up so it used that fuel first

leave it on the setting that works the best for you sometimes if they took the petcock apart thy put it 180 degrees off so it wont be like the manual sais

[cleankat96]

you need to check your vacuum line that goes from the fourth carb to the back of the petcock without it the fuel wont flow in the on position-which it should be in all the time- facing downward is on and there is no off setting the fuel flows when vacuum is applied-

[jbo197]

you need to check your vacuum line that goes from the fourth carb to the back of the petcock without it the fuel wont flow in the on position-which it should be in all the time- facing downward is on and there is no off setting the fuel flows when vacuum is applied-

[Kreylyn]

The answers you seek are here....

http://katriders.com/wiki/index.php5?title=Petcock

Krey

[bconley]

UPDATE!!! Thanks for the suggestions by the way.

So I went out this morning, and fuel was all over the ground. After a quick inspection, I found out that fuel had backed up out of the carbs and filled the bottom of my airbox (I'm assuming this is from the petcock being in the Prime Position. I'm a moron). So I took the carbs off, cleaned out the airbox, cleaned the rubber gaskets and reattached it. That problem solved. I then noticed that the vacuum hose from the 4th carb was not attached at all. So I bought a clamp and sealed it up, but my tank back on and started her up. Got it running, but it sounds more like it's chugging. This could be that it sounds this way without the fairings to deaden the sound, or something could be wrong. My idling is still erratic. It does seem to do better with the petcock in the on position, but will eventually stall. My theory (no matter how noob it is) is that my air filter is effed and need a new one. Any thoughts??

[waffenampt]

hows your air cleaner ?

[bconley]

Again...noob..but are you're referring to the black box that houses the filter?

[bconley]

Problem solved !

So I did some poking around under the tank and found a tube with a that had a piece of tape over the opening. Upon further inspection I found a screw had been placed in the opening. When I started the engine, I felt vacuum pulling into the tube. So I placed that tube on the petcock for the on position and started it up, and it sounded 100 times better. So thanks for the help guys.

[kevin2502000]

Change your oil, it probably has gas in it.

[Astro4x4]

Change your oil, it probably has gas in it.

+1000
Change it fire it up and warm it up then change it again. Gas doesn't lubricate too good.

[Court93kat]

Not only does gas not lubricate very well, but it can also go "BOOM" dealing with the heat inside the motor. That would be bad.

[bconley]

+1000
Change it fire it up and warm it up then change it again. Gas doesn't lubricate too good.

Would poor lubrication cause the engine to sound a bit rougher like it is knocking?

Alright, Update. So with the vacuum tube secured I was getting what I thought was decent idle. Now the idle is erratic, and when decelerating, the tacho dips below 1000 and wants to stall. I know that suction is coming from the carbs. My guess is the petcock valve itself is dirty. Any thoughts? Also my throttle seems a bit sluggish now.

[Kreylyn]

Would poor lubrication cause the engine to sound a bit rougher like it is knocking?

Alright, Update. So with the vacuum tube secured I was getting what I thought was decent idle. Now the idle is erratic, and when decelerating, the tacho dips below 1000 and wants to stall. I know that suction is coming from the carbs. My guess is the petcock valve itself is dirty. Any thoughts? Also my throttle seems a bit sluggish now.

Several possible issues going on here...

• Petcock - Needs at the least cleaned, probably rebuilt. The_CyberPoet sells rebuild kits for around $25 that are super simple to use and fix your petcock issue... make it just like new. Cleaning the petcock during this process is highly recomended. I would pick up a can of carb cleaner dip (about $20 at the auto store) and fully clean the petcock prior to installing the rebuild kit.

• Carbs - Most likely need cleaned and adjusted. The fuel flowing into the airbox/crank case shows that the needles for the floats were not seating correctly. This could be due to dirty or misadjusted settings there. Irratic idle or low/jumpy/hanging idle can be caused by lean pilot circuits due to dirt or bad gas deposits clogging the circuit. Use the carb dip mentioned previuosly to clean them as well really well. Don't put rubber gaskets or pieces in the solution.

• Vacuum Leak - The rubber parts on the bike have a tendency to eventually dry out and become non pliable/hard and or crack. This causes leaks to occur on otherwise "good" looking parts at general inspections. Simple way to look for vacuum leaks is to spray/mist rubbing alchohol focused on parts of the carbs and the boots connecting them to the engine and the air box. If the rpms pick up when you spray a spot, there is a leak there.

There are detailed rebuild threads for both the carbs and the petcock to walk you through doing it, and are simple enough for almost anyone to follow... even if you have not done it before.

Krey

[DarkOwlFAU]

So, I bought my 96 Katana 600 about a month ago. The guy told me when I got it that the fuel petcock is in the on position when it faces the rear of the bike, off when facing the ground, and reserve when facing forward. This goes against what the manual says, and what the fairing says. Here are my questions.

1. So for the last month I've been riding with the petcock facing the rear. I haven't really had any problems with it, except for some erratic idles and the engine stalls occasionally, but this is only after the bike has been in rain (I live in FL, so...yeah). Is this caused by water in my fuel line, or air intake?

2. I put the petcock in the down position for the first time today, as per suggestion by a mechanic. It was fine for 2 miles or so, then I started to loose power and eventually the bike stall. Could it be that the last owner changed the settings of the petcock so that it IS in the On position facing rear, or is it a problem with my vacuum.

I'd really appreciate the help.

Thanks

Ive had the same problem with my 2002 Kat 750...and it seems to be water in the fuel. What i would recommend is to make sure that you are not running the bike on Reserve - since water is thicker than fuel, it will sink to the bottom of the tank and get sucked in to the engine causing the engine to idle harshly or completely cut off depending on the amount of water in the tank.

Empty the tank out and make sure that there is no more water in the tank. This SHOULD take care of the situation if there is water in the fuel. You can also add a little bit of fuel anti-freeze (yes, there is such a thing) which will allow the engine to burn off the water, but may soot up the engine, so use caution.