Bonneville America Forums Forums Technical Forums General Tech 4 carb 600 keihin cvk

I know this is a ba site. i have 2 triumphs. my question is about a suzuki bandit gsf600

The short
4 cvk keihin carbs 32mm
mains outer 2 - 102
mains inner 2 - 105
slowjets - 35
airbox gone due to mods
screws turned out 2.5
1 shim on the needle jet
all internal components clean and functioning
elevation 5000

will start with starter fluid and rev up and die

Prior to these settings it started and ran poorly after 2 years with outer mains at 100 and inner mains at 102 and screws turned out to 2.5. I have adjusted until i at a loss for a new thing to try. I'm hoping for a genius to save me.

Prior to this it ran at sea level with an airbox 100 outers 102 inners 2.5 turns out but this was 2 years ago.

any help is appreciated.

In a former life, I worked for Team Warlock. I'd help tune the boats for the high elevation poker runs in Sac and Lake Tahoe. I know, dream job, but everyone has to eat, right?

Anyway, at 5000' ASL, you should be very rich. You will need to jet way down and adjust the choke set up as well. You went the wrong way with the jets. I'd try 32 for the pilots (may still be rich) start with taking two steps down on the mains.

Another root source of the symptoms you mention could be vacuum leaks. Hard to tell without the bike.

As a side note: at 5000+ elevation, expect a 20% or more power loss across the board. Dropping a tooth in the gearing will help restore some of the performance loss. We would drop 4-5 degrees in prop pitch when running elevations.

how long has the bike been sitting? may be the old gas gummed up the carbs. may be worth going inside them a bit and see how everything looks

Frank

Cowboy,

Thanks for the post
I brainfarted on the elevation bit. I was only thinking that I had opened the airflow with the pod k&n filters. I'm gonna take the jets down to 98s outside and 100s inside and remove the shims from the needles. I can't find a pilot jet that is smaller than 35. I'll try the screws turned into 2. I let you know how she works.
thanks

beanache- anytime and I hope it works. Let me know and... kill whitey...

love the signature... LOL

just popped my 35 slow jets out and looked through them. I can't see any light. i have some extra 45s and i can see through them easily. i should be able to see something through the 35s. i have them soaking in carb cleaner now. i dont have anything small enough to snake through them. any suggestions?

use the wire out of a bread tie, should work like a charm...

worked like a charm. thank you very much sir

cleaned slow jets, turns out-2, inner mains-100, outer mains-98, tightened vacuum tube and removed shims from needles. fired up and ran like a mother. idles at 4000 with the idle completely backed off. not sure what that is about. will have to fix her later. any hints on the idle thing would be appreciated. i'm in the process of fabricating a carb brace.

thanks again

Two things to look at: 1)You may have to re-set up the choke. At little bit goes a loooooong way at 5k'. Very little o2 to start with. 2) I think those carbs are air metered (as opposed to fuel) at the mix screw (the one you have at 2 out). Move them a half turn while idling and see if the RPM drops. The standard 2 turns out is baseline for sea level. I would guess you need to be around 1 or three (depending if the screw meters air or fuel). Try these in reverse order... the second one is easier...

adjusted the throttle bar screws (? not the cables) and was able to close the throttle plates and now the idle screw works but is a bit touchy. i can get her to idle at 1200. the screws are closed to 1.5 turns. not running great but i will fine tune it.

Cowboy,

I have this bike idling well. My air-mix screws are turns way in. When I throttle on slowly she revs nicely. When I jam it on she sputters and dies. I have tried several adjustments but I am now at a loss. I think I'm flooding her. I am not convinced this is the problem.