Low idle , high choke, shim needle help !

[Noobman]

I have a 08 ninja 250 which from the looks of it , I believe to be a California type bike (it has the emissions box / 3 extra hoses on the left side of the gas tank, no idea how it ended up with me in Toronto, Canada)

So, I've had the bike for a year now and I'm overall satisfised, BUT, just the start up and idle always takes a while for me with the choke turned on full blast.

Average temperature is around 10 degrees celcius (maybe colder in the mornings too) currently, but its always on the cool side in Toronto (aside from june-august).

The bike idles on start up in the 1000rpm area or LESS, its always struggling to warm up unless I turn the choke all the way on and the just leave it there for 10 minutes, and even then I have to ride around the block for 5 minutes to get it warmed up properly so I don't stall out in traffic.


The bike is completely stock.


I decided to do the shim needle mod and added two washers on each needle.
I started the bike up and the idle rpm's were much higher this time, around the 1500-2000 range. That looked promising...

So, because of that, I didn't wait much after to let it warm up (maybe waited 5 minutes or less) and just took off onto the main roads. (bad idea).

(I can't remember if I had the choke turned all the way on while I was riding, but why should I have, it seemed to be doing fine from the start up...)

Anyways, barely passing the first stop sign I began to realize a weird "put-put-put" sound coming from the exhaust, never heard this before.

I kept riding.

For the next 10-15 minutes there were just downhills and highways ahead of me until I had to slow down and reached a stop sign on top of a small hill...

The bike completely died...

I was in first gear rolling into the stop sign and the bike just completely died on me, (traffic was beeping behind me), I turned the choke full on and kept trying to start the bike up, it would weakly sputter alive for a brief second then just die again... I had to pull over to the sidewalk and rolled my bike into a parking lot, my friend drove me home so I could get my tools and I had to fix and put the bike back into stock settings (took out the washers) , after that, it ran just like it would when I first got it (fine).

I'm thinking of doing one washer instead of two next time...

What do you guys think ?

[1LoneWolf]

Two washers caused your bike to run too rich and your bike bogged down.

One washer is fine on a stock bike. Two if you have an exhaust system and aftermarket filter.

[DaBlue1]

When you installed the shims, did you remove the snorkel?
Removing the snorkel lets in a tiny bit more air with the extra fuel you're letting into the combustion chamber. By not removing the snorkel, you will tend to be a little richer than normal and may experience a rich bog here or there. One shim really does nothing. Depending on the thickness of the washer, it's about .50 mm. 2 washers work fine when the snorkel is removed.
It can also be done with a stock exhaust and filter as well.

Also your idle rpm speed should be 1350+/- 50 rpms when the bike is fully warmed. Always use the choke when the engine is cold. You don't have to let the bike idle for so long with the choke on. A few minutes and you should be able to pull off with the choke on.

Ride a mile or so and then take the choke off. the bike should be able to maintain a steady idle at this point.To launch the bike while still warming the bike, ease on the throttle, get your rpms close to 3k or so. Don't try to take off just off idle speed. You'll stall almost every time.

[contact148]

I live just eat of you in Durham region.

My 2012 stock Canadian bike does the same yesterday morning 8am bike in my garage.

I start mine like this

full choke start it idles at 1.5 then creeps to 3500rpm.
I put my helmet on my gloves back bike out to sidewalk (25 ft) cloose garage door, ride bike to work

so my bike idles for maybe 2 mins before I ride it after 2 mins or so of rideing I slowly back off the choke if its bogging in 1st off idle I put choke back on take about 6-8 mins of rideing for me to be able to have NO choke

yesterday after work (5pm) i used the choke for maybe 3 mins then did not need it

[subxero]

Sounds like you know how your bike runs normally and the fact that you notice change after shims and then you say it went back to normal after you removed the shims strongly points to the shims.

Like DaBlue1 was saying, thinking you were to rich, you got flooded and then it would not start. P.S. if you keep riding with the choke on full you tend to notice as the bike does not slow down so much when you let off the throttle, it would be hard to miss in braking situations.

What kind of washers did you use?

[rojoracing53]

I know most people don't like the idea of spending $500-600 on their bike so I'm just going to put this here and you can ignore it if its not your thing.

I have a full Leo Vince exhaust with a Dynojet stage 2 kit and I've never had to use the choke, I let my bike warm up for about 30 seconds before I ride off at low RPMs for the first few miles with zero stalling problems. And I ride year rode so that includes temps down to -2C.

My bike idle is set to 1500k warm and when it starts stone cold it will idle at about 800-1000 before I get on it.

[Noobman]

So many awesome responses, I appreciate that.

Ok, so, I'm contemplating trying again with just one washer this time on each needle instead of two.

The washers I used are 1.9mm thick and the inner most diameter is 6.9mm .

The reason I'm trying this mod is because I want to get a better idle rpm (1500rpm instead of my usual 900-1000rpm with choke OFF on a warmish day (15-20 degrees celcius)) ALSO, i would like to decrease the amount of time it takes to warm up (there are times when we are in a rush and just haven't been able to plan ahead)

Lastly, I do have an aftermarket Leo Vince GP Corsa slip on exhaust that I like to slap on sometimes (remember, everything is at stock settings on the bike when I slap it on) so it tends to make the bike even leaner ( use the choke quite a bit with the GP Corsa installed during initial warm up/start up).

So, maybe shimming the needles (one washer this time) will help with that too if I do decide to randomly put it on.

........ *Side note*

When I use these types of washers (i dont have anything smaller atm) I notice that the head of the needle and the rims (sides of the washers) dont line up (diameter wise) , obviously the head of the needle is smaller and therefore sits a little wobbly on the washers. (maybe this was the culprit in my bike dying ? or...)

Also, I had not removed the snorkel when I put the two washers is.

........


SO, my options from what I've concluded so far are:

Option 1: 2 needle shim and snorkel removal

Option 2: 1 needle shim

Option 3: 1 needle shim and snorkel removal

Option 4: Leave as is, stock, (I like to tinker)


What do you guys think/ have concluded from the way my bike is behaving ?

[DaBlue1]

Originally Posted by Noobman

....The washers I used are 1.9mm thick and the inner most diameter is 6.9mm .

....When I use these types of washers (i dont have anything smaller atm) I notice that the head of the needle and the rims (sides of the washers) dont line up (diameter wise) , obviously the head of the needle is smaller and therefore sits a little wobbly on the washers. (maybe this was the culprit in my bike dying ? or...)

Also, I had not removed the snorkel when I put the two washers is.

All of the above is your problem.

The avg washer thickness for (2) 3 mm or #4 washer is approx 1.6 mm. The washers should sit flat and even and fit inside the white plastic, spring seat.

You also can manually adjust your idle speed with varying temp changes as well. When the bike is warmed turn it to 1500 if you want.

[Noobman]

Originally Posted by DaBlue1

All of the above is your problem.

The avg washer thickness for (2) 3 mm or #4 washer is approx 1.6 mm. The washers should sit flat and even and fit inside the white plastic, spring seat.

You also can manually adjust your idle speed with varying temp changes as well. When the bike is warmed turn it to 1500 if you want.

Wow Blue, your awesome.

Yea, I realized the washers didnt sit inside the white plastic caps ( never new they had too :I , I couldn't find any detailed pics of that in DIY's.) You live n learn, sometimes the hard way..

Thanks man.

What do you mean by being able to "adjust your idle speed with varying temp changes as well" ? ( playing with the choke ? I don't want to have to do that...if that's what you mean)

[DaBlue1]

Originally Posted by Noobman

....What do you mean by being able to "adjust your idle speed with varying temp changes as well" ? ( playing with the choke ? I don't want to have to do that...if that's what you mean)

No, this is not the choke. It is a simple, manual carb adjustment.
On the left side of the bike in between the fairing and the frame there is a knob to turn the idle speed up (r turn) or down (l turn). Varying seasonal temp changes can cause the bike to either run a tad leaner or a tad richer than normal. Using the knob in small increment turns, corrects either too high or too low idle speeds.

[alex.s]

Originally Posted by DaBlue1

Removing the snorkel lets in a tiny bit more air with the extra fuel you're letting into the combustion chamber. By not removing the snorkel, you will tend to be a little richer than normal and may experience a rich bog here or there. One shim really does nothing. Depending on the thickness of the washer, it's about .50 mm. 2 washers work fine when the snorkel is removed.
It can also be done with a stock exhaust and filter as well.

removing the snorkel adds air throughout the vacuum range. shimming needles only moves the fuel curve to the left. it doesn't effect the top end of the fuel curve. so by adding shims and removing the snorkel on a stock system (which is already slightly lean from the factory), you are effectively screwing your top end fuel ratio. add in really cold weather's denser air and you're now too lean to make it past 11krpm. also moving the curve too far to the left (as the OP did with too much shim offset) means the midrange vacuum will be too rich

[SafetyPaws]

Originally Posted by DaBlue1

No, this is not the choke. It is a simple, manual carb adjustment.
On the left side of the bike in between the fairing and the frame there is a knob to turn the idle speed up (r turn) or down (l turn). Varying seasonal temp changes can cause the bike to either run a tad leaner or a tad richer than normal. Using the knob in small increment turns, corrects either too high or too low idle speeds.

idle on warm-up is 1500 which was said, but what about after driving a few miles and at optimum operation temperature. Without the choke after driving for a few miles i'm at about 2500ish in grid lock traffic every other morning if i wake up late... Is that to high, should i adjust the knob as well and turn it down? Not sure if thats considered idle, after a cold start im right at 1500 and about 30 sec later or so im good to go. (area P 18" full system quiet core with 3rd wash position and 2.5 turns each on carb [kerry reccommended]).

[DaBlue1]

Originally Posted by SafetyPaws

.... Without the choke after driving for a few miles i'm at about 2500ish in grid lock traffic every other morning if i wake up late... Is that to high, should i adjust the knob as well and turn it down?

2500 is too high. I imagine you are also getting a nice little clunk when going from neutral to first? After a full warm up adjust the idle speed down to 1300 +/- 50 rpms. (no more than 1500)

[MagicMike]

Temps where I am at the moment are getting down to 4 deg cel.

I have a stock '12, with k&n filter, snorkel removed, and I installed 1 shim. Seems to work well.

Full choke on startup, wait a few secs for oil pressure and temp light to go out, wait a few more secs while I put jacket on, remove all choke, put helmet and gloves on, then ride off perfectly.

Idle set to 1500