99 kat 750 fuel issues

[Jhorsley471]

So i bought this last year and rode it till october. Got it out last month and cleaned the tank and carbs out. Not I have to clean carbs everytime I have to start it. Checked the bowls for gas the other day and i have nothing coming from tank to carbs. Help me please....

[Van winkle]

My thoughts go to the petcock. Do you have a vacuum diaphragm style petcock? Another than that I’d look for bad fuel line or a really dirty tank and fuel system. If the vacuum diaphragm is bad it won’t open the petcock. You can pull one fuel off at the petcock, put on a line into a container. Then crank the bike over for a few seconds that should allow the petcock to open and if it does you’ll have fuel run into the container. If you have a vacuum pump you can connect it the the petcock, this will take away the need to crank the bike over. Best of luck.

[Dylan Katanabruin]

hey did you try turning the petcock to pri for prime, the fuel petcock will only flow on reserve or on if the engine is running check that out ,next would to make sure theres no blockages or kinks in your fuel line if theres an inline filter make sure thats not restricting any flow

[Jhorsley471]

I tried it in pri. Still would bog out. I took the tank off and put it in pri and gas comes out

[Dylan Katanabruin]

alright what i would do next would be check the fuel lines for kinks or blockages is it a good flow coming from the petcock when its on prime ? or just a little trickle ? if theres any t fittings on your gas line make sure theres nothing blocking them try taking your gas line off your tank and see if you can blow through it let us know what happens the next step would be to take the carbs back off and insure the float valves arent sticking and prohibiting flow into the bowls

[Van winkle]

J horsley In your first post you said you checked your (bowls) for fuel. Did you check just one or all ? If all were dry it’s unlikely that all 4 floats are stuck. I’m not sure prime will give you enough flow rate to keep the bowls full. Prime the carbs by awaiting a few minutes and tipping bike side to side to insure fuel gets to all the carbs. After that run it. Does it bog right way or only after you have run it for a bit? If bog right away it is like an in carb issue as Dylan posted.

as a thought to be sure you don’t have a flow issue at the tank. prime it, pop a fuel off run a longer one to a container switch petcock back to res or on, restart bike and see if you have fuel flow. This will insure that state of the petcock and tank are good or bad.

[Jhorsley471]

Ok I'll try all of this and let you guys know what's happening. It's been raining here in ohio all week so hopefully this weekend I can figure it all out. I checked the left side carb and nothing was in it. I didnt start the bike with the fuel line off though so that's one thing I will for sure try this weekend to see if it is a petcock issue. All of the needle jets looked good a week ago when I cleaned the carbs for a 4 time in the last month in a half....thank you all for the advice

[Jhorsley471]

And when it is in pri it's a steady flow...I think I'm going to buy a rebuild kit and just rebuild the petcock. And buy a new fuel filter as well. I just want her to start and run like she use to

[mektek]

This sounds familiar. With the petcock on prime, try spraying starting fluid into the air filter and see if it starts and stays running.
I found that a coating can form on the fuel filter element and the pressure from gravity feed is insufficient to break through the surface tension and allow fuel flow.. Certain brands of gas are more prone to this than others.
As a temporary fix I punched a small hole through the paper element to ensure that fuel can always flow. I found this problem would occur in the OEM metal mesh filter too.
For a permanent fix I bought a small filter with a removable element so that if the problem returns I can just remove and clean the element and not have to buy another filter.
I think that the gel that forms in ethanol fuel under certain conditions slowly coats the element. With unpressurized fuel systems the kats have a greater risk of ethanol problems.