99 Kat dies when given throttle

[eatmycrackers]

I have gotten my kat running fine and it idles well, but when I give it throttle, it dies. I had to buy a new set of carbs to switch out the old ones, so I was thinking the air fuel mixture screw? It has a yoshimura exhaust so maybe these new carbs aren't set to the right position? I'd rather have someone more knowledgable offer advice before I take it all apart again!

[92xjunker]

Are the new carbs "new" or used? If they were used, you should have cleaned and set them before install. Had the same issue with my flat slides, cleaned them, now they are running well.

[Stumpy]

+1 on the cleaning and set before install, sync after.

Now you'll have take them apart, clean them up, reattach and sync

[eatmycrackers]

They were used off of a 2006 but very clean I was able to have them opened and I took a good look before buying. I just adjusted the screws, they were set to FIVE full turns out I think so I readjusted them to 2.5. It still doesn't throttle for some reason. When I go ahead and give it throttle it dies still.

[Stumpy]

It will continue to do that forever until you clean them

[arsenic]

If it dies when you give it throttle, it's not "running fine".

[eatmycrackers]

for some reason thought the previous owner cleaned them, but now that I think back, he only showed they were "Pretty clean". Im guessing some jets are clogged. I'll update you guys once I clean them. Thanks.

[crazycraven420]

there are several small passages that need to be cleaned also so do yourself the favor of reading the carb cleaning how to. If those screws were turned to 5 turns he was prolly trying to make his run without doin it right.

[1998katana600]

Hi, I have a 1998 Kat600 that I'm trying to get running also..I spent days cleaning the varnished carb, installed the rebuild kit, put everything back as carb 101 video showed (awesome video by the way..thank you! life saver!), but the bike starts with only the choke on (halfway) and when you throttle it just dies...I can put about couple inch turn while the choke is halfway and drive it 25mph in 2nd but thats all. when I turn the choke off or throttle it..bike dies. Also..after the bike warms up the idles goes up and down sometimes. Do you guys believe I should take everything apart..start all over and clean them again? what specific area should I be looking at? I brushed, dipped, and cleaned so much...thank you for your help

[Stumpy]

Sounds like another round of carb cleaning for you

Check your needles too. If it idles fine, and runs in the low range, may be a problem with the mains. Make sure everything is within spec, especially your annulus (annuli? I forget the plural). If they are not perfectly circular, replace.

[crazycraven420]

check for air leaks as well, when you open the throttle you may be sucking air thru an overly leaning out the air fuel mix. Get a flammable spray (starting fluid etc) an slowly spray every joint or seal between the airbox an motor as it idles, if it revs up, drops idle or dies you have a leak. Eliminate that a problem then dive back into carbs