Start but pops (backfire) after letting off throttle

[a17322a]

Sorry to start another thread, but i'm lost.

First of all, i have a 94 kat 600. stock everything i believe. i haven't ridden it in 2 months, but i do start it every week to get things running through (even though somtimes i would have to crank 5+ times with choke on for it to start, but it ran after that), choke was on it for a while to let it idle, usually running 2k for a few minutes till it idles normally, last week, i went to start it and it backfired since it didn't start, so i looked into the spark plugs and they were flooded. Now, i have changed the plugs with iridiums, and went ahead to change the air filter too to a OEM one (old one was a Uni branded one that was quite dirty). Now, it takes a few tries for it to start with choke on and still its hard to get it to start sometimes, it cranks but it seems hard for it to just start. IF and when it does start, i have to hold the thottle steady or choke it for it to even stay on. And when i let go of the throttle slowly, it would stall or it would back fire(popping noises). so am i running rich or lean or soemthing?

how can i go about fixing this or diagnosing whats wrong, any ideas?

Thanks a lot, sorry for the newbie questions.
I'm not too great with motorcycles, but i am kind of handy, i know a little bit about cars and can do regular maitenance items, but thats about it.

Thanks KR for all the help for me to even get this far on changing spark plugs.

[arsenic]

it's not a back fire, it's an after fire, your running lean You can fix it by turning the a/f screws to 2.5 turns out. The a/f screws are under brass caps as Suzuki's feeble attempt to appease the EPA. Drill out the brass caps and adjust them to 2.5 turns out. Stock is 1.75 and that's too lean.

[DOCTORNITRO]

You're sure getting alot of mileage outta that pic lately chris!

[arsenic]

it's page 13 in my photobucket crap. You know that's the same damn pic on Factory Pro website if people would just go there. yeah, like that's gonna happen

[Jerkeife]

what is this Factory Pro that u speak of?

[a17322a]

Arsenic (Chris?) thank you so much, i'll give it a try tomorrow, do i just tighten it all the way down (turn it clockwise) then loosen (counter clockwise) by 2.5 turns? is this the correct way? also, when u say drill out the brass caps, do u mean drill it out with an actual drill bit like removing a rivet, or to unscrew or pop them off?

again, Thanks a ton, i would like to show some appreciation, but i don't know how haha, should have a reputation system like the other forums i am in...

[The CyberPoet]

it's not a back fire, it's an after fire, your running lean You can fix it by turning the a/f screws to 2.5 turns out. The a/f screws are under brass caps as Suzuki's feeble attempt to appease the EPA. Drill out the brass caps and adjust them to 2.5 turns out.

+1

I would also like to point out that the choke is not an on/off control -- it has a lot of in-between positions that can be used as needed (referencing the wet plugs)

Cheers,
=-= The CyberPoet

__________________________________________________ ________
CyberPoet's Katana Maintence and Upgrade Parts Offerings
The Best Metal Steel Aluminum Motorcycle Tire Valves in the World, plus lots of motorcycle & Katana (GSX600F / GSX750F) specific help files.

[scottynoface]

Part of your problem is starting it up and letting it run once in a while when you're not driving it regularly. That fouls plugs really quickly, as does leaving the choke on too long especially when you don't ride it after turning it on. You get the fuel in the passages and then it sits, gums up, then fresh fuel on top of it runs through, sits, and gums up.

And good call on getting rid of the Uni, I had one, it was awful.

[arsenic]

Arsenic (Chris?) thank you so much, i'll give it a try tomorrow, do i just tighten it all the way down (turn it clockwise) then loosen (counter clockwise) by 2.5 turns? is this the correct way? also, when u say drill out the brass caps, do u mean drill it out with an actual drill bit like removing a rivet, or to unscrew or pop them off?

yeah, I'm Chris, exactly, tighten them until they seat, just lightly, and count the turns out. Take like a small drill bit, drill a hole (not to far the screw is right there) then screw in a self tapping screw and yank it out with a pair of pliers, the cap will come with the screw.

We had rep points for a little while, that was a friggin joke. Just for saying that, I'm giving you negative feed back

[The CyberPoet]

We had rep points for a little while, that was a friggin joke. Just for saying that, I'm giving you negative feed back

I didn't even notice when the rep-points system disappeared... hmmm...


Cheers,
=-= The CyberPoet

__________________________________________________ ________
CyberPoet's Katana Maintence and Upgrade Parts Offerings
The Best Metal Steel Aluminum Motorcycle Tire Valves in the World, plus lots of motorcycle & Katana (GSX600F / GSX750F) specific help files.

[Kreylyn]

Adjusting the carbs will make it idle better but it still will be a little hard to cold start with out a +5 ignition advancer, correct?

Krey

[Frenchcropper]

I didn't even notice when the rep-points system disappeared...


Nah - I think it's on here still, but just autolocks when the characters 'K', '&' and 'N' appear together!!

[The CyberPoet]

Adjusting the carbs will make it idle better but it still will be a little hard to cold start with out a +5 ignition advancer, correct?

Krey

The advancer doesn't make it easier to start -- it makes it much faster to warm up. The jetting being richer makes it easier to start (ditto a good air filter that provides sufficient resistance to vacuum loss). A well-tuned jetkit can make it a breeze to start (for example, the 98+ Kats with the Ivan's don't generally need any choke above 50 degrees).

Cheers,
=-= The CyberPoet

__________________________________________________ ________
CyberPoet's Katana Maintence and Upgrade Parts Offerings
The Best Metal Steel Aluminum Motorcycle Tire Valves in the World, plus lots of motorcycle & Katana (GSX600F / GSX750F) specific help files.

[a17322a]

Thanks everyone, i adjusted the A/F on the carbs via the screws, apparently someone did 2.5 turns out already b4,so im not sure, i just did another 1/4 of a turn outand it seems to run a bit better, not sure if its 100% yet but i'll see how it runs for a few days

Again, Thanks everyone!

[a17322a]

sorry guys/gals, im having some more issues now, the right 2 header are cold (not getting enough fuel/ running lean?) while the left 2 get up to normal temperature, it does take a few times for the bike to crank over some times and start, with or without choke (50-60 degree weather). also, when im trying to crank it, after letting off the starter button, i would hear a pop sometimes. i rode it around last time and it has a hard time idling, it would just die, i could get the rpms up sometimes, but there isn't any power at all, very bad throttle response. i took the plugs(iridium) out and the right 2 plugs were clean as a whistle while the left 2 had a slightly black color any ideas on what i may need to do? i haven't cleaned the carbs yet or opened them up, i have never cleaned carbs but i am mechnically capable to and will do it this weekend or whenever i have a day off work. any other things i should look for? other than cleaning carbs? thanks everyone for the help. i love this forum so far.