Hello all. I am an idiot! I decided to make a carb change before a trip...and the bike is no longer running right. Woohoo!

I know there are many carb threads and I've read some of them but everyones running something different, it seems.

The bike ran fine before I messed with it. It only required the choke to be on for a 30 seconds then it would idle on it's own when cold. It did seem a little rich though. I have/had a trip coming up at a lot higher elevation so I was worried if it was rich here, then it would be a lot worse there.

I inquired on ADVrider about my setup. I bought the bike used.

'06
Stock Exhaust
Smog stuff removed
Larger snorkle
3 1" holes drilled into the top of the airbox with those foam inserts.
Kuoba adjustable fuel screw

MAIN DJ 128
NEEDLE DJ, 3rd position from top
PILOT Keihin 40


WestOzKLX suggested I go back to the stock Keihin 35 Keihin Pilot and call it good. I changed the pilot and adjusted the fuel screw to 2 turns out. Now I'm having problems. BTW, I don't blam WestOzKLX.

It starts up but requires the choke to be on for a lot longer than before, which I'm guessing is expected. I then took it for a spin to adjust the fuel screw.

I rode it for about 20 miles to get it nice and hot. First off, the idle won't stay consistent. It wants to fluctuate about 500 or so rpm. Second, if I set it to around 1300 rpm, shortly down the road it's idling at 4-5000 rpm. I'd stop and readjust it then it would climb back up. Also, it's not returning to idle very quickly. I tried adjusting the fuel screw but with the idle fluctuating, it was difficult.

It pulls through the gears fine. It seems to be something with the idle circuit?

I checked for air vacuum leaks. I've had the carb apart twice now double checking everything. I also checked the throttle cables for adjustment/binding. The float level was just a tad low so I brought it back into spec.

Any ideas? Does it sound like I just need to get the idle circuit adjusted properly? I'm running out of ideas.

EDIT: The title should be man, not men. See, I told you I wasn't smart!

 

Hey eugene to the forums, someone will be on shortly with some good information and or suggestions. I have only one for ya, get over to the new members area and give us a proper introduction so we can all give you the right welcome. LOL and I'll edit the title for ya. I mean after all with my OCD I was going to change it for ya anyway. hahahahaha

 

Thanks deej. I could have swore I posted here before about a suspension question. I think I'm loosing it!

 

sounds like an air leak. pull the top off the carb and make sure the rubber skirt is seated in the groove correctly.

 

Try leaning the idle air screw.

 

I'll take another look at it. I did notice that the diaphragm is a little bit fiddly to get back in the groove. I might try that warm water trick I've seen posted.

I tried that before and it didn't help. Also, when the 40 pilot was in, the fuel screw was 3 turns out. Theoretically, when I went to the 35 pilot the fuel screw should need to be richer.


I need to follow lcpl0331's suggestion and look for other air leaks. If I can't find anything I think I'm going to go back to the 40 pilot and see how it runs. Obviously, if it still doesn't run right I have other issues.

If the 40 pilot cures the problem, I don't understand why the bikes likes a larger pilot. I've seen where people are running a full aftermarket exhaust and open airbox and they're still using the stock 35 pilot. Not sure how/why my bike would be different. I know some are at higher elevations but I've seen that setup close to sea level, which is where I'm at.

 

Another question. Which way does the slide go in? I have the hole at the bottom that's sometimes drilled out, beside the needle hole. I have the hole oriented towards the front. Is this correct?

 

Mine will only fit one direction...

 

Thanks Slippery. I realized that when I took the carb apart again.


I put the Keihin 40 pilot back in and it seems to run fine. Now I'm confused.

As I asked above, why would it run fine with the 40 and not the 35? I live in Indiana at around 1K feet. I've got the stock exhaust, larger snorkle, 3 1" holes with foam inserts in the airbox lid, and uni filter. Everything else is stock. I've been getting between 45-50 mpg with the 40 pilot.

 

I'm running the 132 and 40 jets, no airbox lid and its flawless.