New Idle Problem

[StlStallion]

Ok I've done a search and check the normak thing. I used the new carb cleaning write up and totally cleaned the carbs. I've check the vacuum at both sides of the carbs. I haven't done a carb synch yet though. But when I hooked the carbs back up I started it with the idle screw all the way out and the choke open. It started fine and as I slowly let the choke back in I would incrementally have to bring the idle up with the idle screw. However with the choke all the way closed I can't get the idle to come up and sometimes it dies when I give it throttle. What is the next think I should check. I have the carb synch tool coming in this week. If I can't get it to idle right though how am I suppose to do that?

[ndn]

how did you try and sync the carbs without the tool? (drill bit, by eye, etc..) also what are your mixture screws set at?

[StlStallion]

THe mixture screws are set at 2 1/8 turns out. I haven't tried to synch the carbs at all yet, I'm hoping the tool will get in tomorrow to do it. But I thought that I had to have it set at the running idle in order to synch them. And I incorrect in assuming this? I haven't tried anything yet.

[The CyberPoet]

THe mixture screws are set at 2 1/8 turns out. I haven't tried to synch the carbs at all yet, I'm hoping the tool will get in tomorrow to do it. But I thought that I had to have it set at the running idle in order to synch them. And I incorrect in assuming this? I haven't tried anything yet.

You sync it with the idle set to a special hot "Fast" idle of 1850 or so, not standard idle. Turn it up to hit 1850, turn it back down after you sync it.

Cheers,
=-= The CyberPoet

[StlStallion]

THat is the problem, I can't get the idle to hit 1850. It is just sits at like 900 or jumps to about 2500. I took the head off to measure the gaps in the valves, could I have not put something back together there? THe carbs are spotless so I don't think there is a problem in there, the floats have been measured and everything. Also I have a good seal between them and the airbox and them and the engine, so I've kind of ruled them out. Is the next thing to look at the spark plugs (which are new) and the CDI?

[The CyberPoet]

The problem is vacuum-related or fuel-related in some sense. You can rule out any electrical basis or electronic control basis (period) given your symptoms -- there is no electronic control over idle. My guess is that you'll find it was something fairly simple, like forgetting to reconnect the airbox drain hose (or cap the other end), a badly seated velocity stack, bad carb o-rings, or a defective vacuum diaphram on a carb slide.

It may also be that you are putting too much push on the idle adjuster when you are turning it, or that it's sticking somewhat (there is a spring in the cable adjuster to keep it from rotating freely). It could be that small changes are snapping back, while big changes are just way to big.

Good luck!
=-= The CyberPoet

[rwcreigh]

i agree,i bet a line is loose or fell off.take one more look at it i think you will find the problem.good luck

[StlStallion]

Well I guess I'll tear it apart again this weekend. Theoretically when I hook the synch tool up, if there is a vaccuum leak in one of the carbs it would show on there as being lower than the rest correct?

I check the orings and non were flat, the all seemed to be in good shape. Could it be a problem with the air screw? To get it straight the future in the screw the less air (ergo the more fuel) in the mixture correct?

[Fingers]

Stupid question -- have you tried letting the bike warm up completely?

[ray90813]

actually i had the same problem with my pre 98 kat when i bought it, it was sitting for years. It wouldn't start at first so I took the carbs apart, cleaned and replaced all the o-rings. Checked the float level and jets and adjusted them the same, when I put it together I couldn't get it to idle steady, and every adjustment I made w/ the idle adj screw or choke either stalled it or made it idle too high, anyways to make a long story short, what it ended up being was that my butterflies were so out of sync initially that it created all these problems, so what I ended up doing was using four 1/8" drill bits I synced them as close as I could on a bench, slapped it back on,warmed it up around 1600 rpm,shut it off hooked up gauges and was able to sync them correctly, dont know if it'll work with your bike but thought i'd give you some input.

[StlStallion]

Yeah I've been letting it warm up fully.

I'll give the drill bit thing a try and see what happens. Can't hurt anything now. THanks for the advise.