Choke stopped working - slowly dripping gas - connected?

Got questions? We got answers....
Post Reply
User avatar
ihatefalling
Supporting Member
Posts: 410
Joined: 09:30 am Jul 20 2008
Country:

Choke stopped working - slowly dripping gas - connected?

Post by ihatefalling »

2005 - 220

For some reason the choke recently stopped working. The knob still goes up and down, but it doesn't make any difference. Still runs at an idle speed whether it's up or down.

It also started to slowly drip gas.

I wonder if the two are connected. I'm gunna clean the carb and inspect the needle and float to make sure they're ok and seating properly.

I did some searching. Am I on the right track? Sorry if its kind-of a repost.
Last edited by ihatefalling on 09:00 pm Nov 19 2008, edited 1 time in total.
2005 KDX 220
R&B Carb Mod
R&B Head Mod
Fork Swap - 99 KX125 Valved for B woods plush
FMF Gnarley
Airbox Mod
Tagged
GS
Member
Posts: 644
Joined: 11:33 pm Feb 17 2005
Country:
Location: Vancouver area, Canada

Post by GS »

Let us know what you find.

I'd bet the choke is still functioning, but making little difference
User avatar
canyncarvr
Gold Member
Gold Member
Posts: 6943
Joined: 01:07 pm Nov 05 2004
Country: US
Location: The Mythical State of Jefferson

Post by canyncarvr »

Re: '...slowly drip...'

From one of the overflow tubes? That's a common KDX situation brought about by maybe a number of things, sometimes more'n one at a time:

1. Float level too high
2. Kickstand too bent
3. Float needle leaking
4. Float needle seat bad

Check your float level..maybe even drop it a couple mm under spec.

The choke won't necessarily make the engine speed change. It's an enrichment circuit NOT including a throttle position change (unlike a carburetor on a car 'fer example).

That said, a properly functioning choke in a decently jetted bike WILL effect idle speed. You might have something plugged up somewheres. Check the upstream (filter side) of the carburetor, looking for airflow being good through the choke circuit. It comes from one'a those little holes drilled into the carb bell.

In the below pic..it's NOT the hole the air screw goes through:

Image

On the fuel side of things, make sure the float bowl is OK...that the brass tube you see below (note: This is NOT a PWK float bowl) is in place.

Image

If your jetting off enough that the choke won't effect idle speed..then...it won't! :wink:

The answer to your question is, 'No'. An overflowing/dripping carb doesn't cause your choke to not work correctly.

Consider the source
Using a perceived level of knowledge to boost my self worth.
Non impediti ratione cogitationis

bike profile: !clicky!
User avatar
ihatefalling
Supporting Member
Posts: 410
Joined: 09:30 am Jul 20 2008
Country:

Post by ihatefalling »

OK...thanks for taking the time. Yes, it's slow dripping out of an overflow tube.

I think the kickstand is ok, so I'm gunna inspect and clean the other parts and adjust the bowl a little.

Will let get you an update ASAP.....THX
2005 KDX 220
R&B Carb Mod
R&B Head Mod
Fork Swap - 99 KX125 Valved for B woods plush
FMF Gnarley
Airbox Mod
Tagged
lemmy
Member
Posts: 221
Joined: 12:36 pm Jul 25 2008
Country:

Post by lemmy »

>|<>QBB<
canyncarvr wrote:
Check your float level..maybe even drop it a couple mm under spec.

.
I just want to clear up my confusion on this. By dropping the float a couple of mm under spec, you would actually do this by increasing the value of the float height measurement right? (float height measurement being the distance from the carb body edge to the bottom most point of the float when the fuel just begins to flow past the float valve). I just recently set mine to 19mm (with the max specification being 18mm I believe).
User avatar
canyncarvr
Gold Member
Gold Member
Posts: 6943
Joined: 01:07 pm Nov 05 2004
Country: US
Location: The Mythical State of Jefferson

Post by canyncarvr »

Over, under, more, less...whatever........ :wink:

You are correct, and I'm sure not at all confused. A 'dropped' float level will result in 'more' mm being measured from the carb body.

I know you know all that (I question the 18mm part, but you DID say 'max')..but for the casual reader....


'Dropping the float' means making the float lower when the float needle is seated. It being lower makes the fuel level lower in the float bowl. 'Lower' meaning reckoned in the orientation of an installed carb.

'Under spec' meaning the the float line you are measuring to is under (below) the specified measurement (float is lower in the bowl than it would be if it was set to the spec'd mm), having nothing to do with the actual measurement number. It's all semantics anyway, as the procedure to adjust the float generally involves having the carb upside down..or at least sideways, so 'under' becomes the new 'over'!

Neat!

K.I.S.S. (the last 'S' for 'Sir!')

Here's a quick write-up on it:
Some webpage wrote: Measure the height from the bottom of the float to carburetor-body gasket surface. When checking the float height, the float should be resting, but not depressing, the spring-loaded float valve pin. This can be done by tilting the carburetor until the float tab just makes contact with the valve pin. If adjustment is needed, bend the metal tab on the float arm until correct height is obtained.

The important part about this is the '..resting (on), but not depressing...' the pin. If you simply turn the thing upside down and let the floats rest on the pin, it WILL be depressed!


You will find that the PWK floats have a mold line that will be parallel to the carb body when the float level is adjusted to spec (see below). Simply adjust the tang so that mold line is not quite parallel no more..and you will have a float 'level' that is 'under spec' (again...sits below the specified number). With the carb upside down, the needle to your left, the mold line will be sloping 'up' from left to right.

Do pay attention to a couple of things:

1. When you adjust the tang, do NOT tweak the float arms. Both floats should be 'the same', one not lower or higher than the other.

2. Ensure the floats are away from any carb part, float bowl or carb body. No part of either float should touch any part of anything that would inhibit its free movement up/down.

3. Don't hamfist the bowl on (and in the process mess up what you just checked under #2). That brass tube may seem to be obstructive until you get the hang of 'scooping' the bowl onto the carb body.

4. When you put the carb back in the boots, make sure the locator tab cast into the carb body on the downstream side is correctly aligned to the corresponding slot in the receiving boot. It's easy to have it 'off' a bit, which will lead to the carb leaking even AFTER you have fixed whatever may have been leaking on the INside.




BTW... a PWK 28 float spec is 19mm. The 35-39 PWK is spec'd at 16mm. I didn't check, but I believe the Kaw manual specs 16mm. At least that's the number I recall.

From some pdf that looks official:

Image

Not that it matters, as I've not used a mm number to check it for years.



Easy peasy!!

**edit**
It occurred to me that if the choke has no effect on idle speed, it does not necessarily mean the choke circuit is not working. Maybe it's always 'working'. That is by far a more likely scenario..either the plunger being bad and not sealing off the fuel, or the assembly being so full of crud it doesn't seal. Both of those are fairly common situations.

Ever try starting your bike without pulling the choke up? Maybe it starts as well if you don't as if you DO. :hmm:

Consider the source
Using a perceived level of knowledge to boost my self worth.
Non impediti ratione cogitationis

bike profile: !clicky!
Post Reply