Choke Idle Speed has Changed

[patw]

Hey all,

With the choke fully on, my bike has recently changed the choke idle speed. Normally, full choke will give around 4-5k RPM, lately it's gone down to 2-2.5k at best.

This seemed to happen after I accidentally left the choke on 1/2 while taking a 2hr long ride. Is it possible something has loosened up or did I bork something serious?

The engine with choke fully off still feels perfectly normal.

[kkim]

check to see if you have the proper amount of freeplay at the carb end of the choke cable.

[00NissanNinja]

Sorry to thread jack but when you turn the choke on does the rpm's immediately go up or do they go up over time at idle. Cause when I turn my choke on it just goes to regular idle then eventually goes to higher rpm. I think my freeplay is correct as well.

[patw]

No worries, might be a related question.

What it used to do at full choke is just hesitate for a bit and then drive the RPM's up very quickly... almost like hitting the throttle. I also found if you ramp up the choke too quickly it could just stall out the bike.

What I normally do is put it on full and start it while it's full, that way there's no stall problem.

I'm going to check my free play right now, just gotta find the big-a$$ phillips screw driver head I use for the side panels... no more stripping that screw

[patw]

Originally Posted by kkim

check to see if you have the proper amount of freeplay at the carb end of the choke cable.

As usual, kkim you are 100% correct. There seems to be too much slack in this cable. At full choke I can still push the little actuator with a screwdriver and it goes back to it's normal high RPM choke idle.

So how does this slack happen, and how can I fix it?

EDIT: Found it in the manual on page 103, they recommend having Kawi look at it. Bugger

[kkim]

Originally Posted by patw

EDIT: Found it in the manual on page 103, they recommend having Kawi look at it. Bugger

take a good look at where the cable terminates at the carbs and look at the adjustment/locking system they have set up. you should be able to figure out how to loosen the locknut, adjust the cable by turning it to the proper freeplay and relocking the lock nut.

cables stretch, which is why they need to be checked and adjusted.

[00NissanNinja]

Originally Posted by kkim

take a good look at where the cable terminates at the carbs and look at the adjustment/locking system they have set up. you should be able to figure out how to loosen the locknut, adjust the cable by turning it to the proper freeplay and relocking the lock nut.

cables stretch, which is why they need to be checked and adjusted.

So do you think my adjustment is out of spec or is this just how my bike likes to act?

[The Red Darin]

Originally Posted by 00NissanNinja

Sorry to thread jack but when you turn the choke on does the rpm's immediately go up or do they go up over time at idle. Cause when I turn my choke on it just goes to regular idle then eventually goes to higher rpm. I think my freeplay is correct as well.

My choke does the same. Bike starts out at a normal idle, then gradually increases to 3-4K over a minute or two. The guy that delivered my bike from the dealership said that was what it was supposed to do.

I also tend to have to start with the choke engaged or the bike will stall... unless I increase choke in tiny increments.

[kkim]

Originally Posted by 00NissanNinja

Sorry to thread jack but when you turn the choke on does the rpm's immediately go up or do they go up over time at idle. Cause when I turn my choke on it just goes to regular idle then eventually goes to higher rpm. I think my freeplay is correct as well.

mine stumbles to life from a cold start with the choke lever at full "on" and then will build to about 3k. I then adjust the lever so the bike will idle at about 2500rpm. after a few minutes, the choke can be turned off and will idle at the 1500rpm I have my idle set to.

[patw]

Originally Posted by kkim

take a good look at where the cable terminates at the carbs and look at the adjustment/locking system they have set up. you should be able to figure out how to loosen the locknut, adjust the cable by turning it to the proper freeplay and relocking the lock nut.

cables stretch, which is why they need to be checked and adjusted.

Cool, you have me convinced.

To get at the area, do I removing fairings and gas tank?

[kkim]

you will need to at least remove the left side fairing... might have to remove the right side too.

I do believe the gas tank can stay on, though.

hollar up if you have any problems.

[CZroe]

My choke did this too but it was a much shorter ride (two blocks away). I actually tried to turn it back on at a light when I realized that I wasn't warmed up enough and that's when I noticed it. I've been dealing with it for another 7K miles since then. I asked the dealer to look at it on my last three services and they never did anything.

[00NissanNinja]

Originally Posted by The Red Darin

My choke does the same. Bike starts out at a normal idle, then gradually increases to 3-4K over a minute or two. The guy that delivered my bike from the dealership said that was what it was supposed to do.

I also tend to have to start with the choke engaged or the bike will stall... unless I increase choke in tiny increments.

Mines does those things like you and kkim described but it takes quite awhile before the revs build up like 5 min sometimes longer and this is on warm and cold days.

[kkim]

Originally Posted by 00NissanNinja

but it takes quite awhile before the revs build up like 5 min sometimes longer and this is on warm and cold days.

this is definitely not normal.

describe your cold start procedure.

[00NissanNinja]

To start from cold, I'll turn the choke up (maybe about 3/4) and then start the bike. It will then slowly get up to about 1000rpm (within a couple sec) and sit there for like a minute, then it will get to idle speed and at that point it takes around 5 min for the idle to go any higher than that. I try not to mess with the choke to much since it might make the bike stall during this time. I also have set my bike to idle at 1500rpm. When i first got the bike if I turned the choke fully on and let it run for a few minutes the bike would cut of by itself without me doing anything to it other than waiting, this was fixed by adjusting the idle to what it is now.

[patw]

Originally Posted by kkim

you will need to at least remove the left side fairing... might have to remove the right side too.

I do believe the gas tank can stay on, though.

hollar up if you have any problems.

Removing both fairings is quite simple (if slow the first time), thanks a lot for your DIY Fairing article. I might do a video to this one later.

What I saw when I was in there:

There's a metal steel bar with 2 screws with plastic washers under them. Pulling the choke causes this bar to slide horizontally back and forth which pulls a tiny plunger in the side of <something, not sure what it is, guessing the carb>. The plunger is not flush to the metal bar, there's about 1-2cm of gap. Pulling the choke about 1/4 of the way results in closing that gap, then the remainder actually pulls on the plunger. So here's my questions:

- Is the plunger supposed to be flush with the metal slider.
- What do those screws actually do, other than keep the bar straight?
- What pulls the bar back? It looks like it's on a spring or something.
- Where do you adjust excess cable? The actuator that moves the bar seems to be just some folded metal around the wire itself with a small end cap on the wire.
- Is it better to fix the wire, or just put some sort of shim on the plunger?

n00b mechanic monkey is confused.

[kkim]

have you read pg. 2-17 of the service manual?

[patw]

Originally Posted by kkim

have you read pg. 2-17 of the service manual?

I don't believe I have one of those, just an owners manual. I'm guessing it doesn't come with the bike?

[00NissanNinja]

Originally Posted by patw

I don't believe I have one of those, just an owners manual. I'm guessing it doesn't come with the bike?

No you have to buy it, its like $60

[headshrink]

I guessing your bike is 100% stock???

[patw]

Originally Posted by kkim

have you read pg. 2-17 of the service manual?

I "found" an service manual and based on the images it looks like I'll need to find that cable adjuster somewhere. Thanks again!

Bike will stay in one piece for tonight, doing my final M license test tomorrow afternoon!

Originally Posted by headshrink

I guessing your bike is 100% stock???

Yeppers. I've changed fluids and lightbulbs.

[00NissanNinja]

Checked my choke free play and it is correct. I found there is a spot where the choke will cause the idle to shoot up (when cold it is idling at 2,500 with the choke will go up with time), If I go past that it will either cause the bike to shut off or idle erratically. Additionally if too little choke then it will simply idle weirdly for a while.