High idle

[Reddog74usa]

Bike is a 98 FXST. When warmed up she idles just a bit on the high side even with the idle screw all the way out. I have replaced the intake and carb seals, checked the cables for slack and checked for an air leak with all ok. It has done this with the stock cv and the new just installed Mik 42. Bike only has 9K miles on it and the only other thing I can think of is the voes may be leaking. Anyone run across this? What did you find? Didn't see any cracks in the intake manifold either. 

[Burnout]

Stuck choke (starting aide) / enrichener.

[Reddog74usa]

Checked that as I was goin down the road. Seems to be working as it should. Just tested the voes for a vacuum leak along with the hoses and T. All were good but the end that fits the carb was a little big so I replaced that hose. I put the original cv back on and it runs great and I can set the rpm's at a good idle now so I believe the next step is to maybe give that enrichner cable a little more slack in case it is holding the plunger a bit open as it is adjustable since it is a mikuni cable. It was set as per the manual from mikuni. It wasn't a big leak so maybe the enlarged end was the culprit. I'll post my findings when I get er done...

[Reddog74usa]

Has to be this new Mik carb. I have checked it all and it idles fine with the cv. Worst thing is chasing a bad new part. Bought it new on ebay. it's not a copy as it has the mik casting on the side and the logos on the jets BUT it had a sticker on it assembled in Mexico. Didn't know mikuni was subing out the assembly on these otherwise good quality carbs so watch what yer buying these days.

[bobo]

cable may be on the tight side, if you look through the carb towards a light and see light the throttle plate is not shutting tight. it may not be centered, just a few things I would look for

[Reddog74usa]

Thanks but Mikuni's don't have a throttle plate.

[Burnout]

If the cable is stopping the slide from dropping, that would be a cause.
Some of the Mikuni's use a different length inner cable.

[Reddog74usa]

Looked at that also. Even tried it without the cable on the carb. I have mik 42's on two other bikes and when looking at the slides both of them are sitting much higher in the venturi and idle fine. The slide on this carb is as low as it can go and still it idles high. I don't think I missed a thing trying to find the cause. I pulled it and now have the cv back on it and the bike runs and idles just fine so this new carb is going back.