idle?

[ortiz348]

My katana will not idle under 3,000 rpm. I set the idle screw so it idles around 4,000 rpm but it still jumps randomly (sometimes 6,000 rpm and sometimes it drops below 3,000 rpm and stalls). Any ideas?

[f00lishroy071]

Should be in mechanics 101. Did you just buy the bike or did something trigger this? Maybe your pilot screws need adjustment or carbs need cleaning.

[smokintalon]

pull the carbs and clean them. the carbs on suzuki's are very touchy and the least bit of trash will cause problems. Take your time to clean them thoroughly or you WILL be doing it again! Use seafoam to soak them in. This will loosen up the trash and varnished fuel. Take your time with them. Look at carbs 102. This is a step by step guide on cleaning them.

[joe]

Also, be sure to check for vacuum leaks. Common problem areas include cracked intake boots (where the carburetors attach to the engine) and worn out intake boots on the air filter side (where the air filter box attaches to the carburetors.

Also make sure the air filter element is firmly attached to the box and make sure the drain hose for the air box is plugged.

While you are tearing into the carbs make sure all of the tiny o-rings under the black caps are present and in good shape.

These carbs, I have found through much trial and error, are sensitive to vacuum changes. Also, if you have a K&N filter on an otherwise stock bike, remove it and go back to the stock element.


I've also read on here that high idle can be a characteristic of a lean air/fuel mixture.

[ortiz348]

Thanks. I figured I would have to clean the carbs but I was dreading doing it. This is my first bike and I know a little about it but not much. I went to the local suzuki dealer and asked for a quote on how much it would cost to get all 4 carbs cleaned... they said over $500! That's nuts. I bought the bike for $1500. If I do decide to clean the carbs myself will I be able to balance/synch them?

[JokerZwild]

500 bucks is a crime!!! Someone should be shot for even quoting you that price. Go look up Carbs 102 thread, Grab a Clymber manual and a decient sync gauge and have at it. Its not all that bad so long as you pay attention to what your doing and make sure you dont wind up with any spare parts when your done.

[smokintalon]

there's some people that have used a venier caliper to set the synchro. I did mine and they are pretty darn close. I think it's in the carbs 102 thread??? If not, here's a link to another forum's thread that the guy labeled everything in the pics. Shows how to adjust everything, gives specs, etc.

http://www.gixxer.com/forums/showthread.php?t=159718

--And sorry for linking another forum, but its a good write up on these carbs

and here's another link for adjustments, if you need it. It might help you understand how the different compnents inside the carbs work and what happens when you make adjustments.

http://www.factorypro.com//tech_tuning_procedures/tuning_carbtune,CV,high_rpm_engines.html

[smokintalon]

something else too, aftermarket filters, like K&N cones, dual carb filters, etc will have an effect on the idle. They won't cause what you are experiencing, but they will cause erratic idle and sometimes cause the bike not to idle at all

[jedney]

Welcome to KR!