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More fuel problems

Posted: 12:16 pm Sep 03 2017
by Greatbrit
ok this whole fuel problem has got me really really frustrated. i cant seem to fix it. These are things that are happening.

Bike starts 1,2nd kick. idles great.
No air leaks

air screw is 2 and a half turns out.
when i put the front brake on and shake the bike it dies??
.
spark plug is black dry kinda sooty.
my fuel mix is 40.1

i have changed main jets gone from 148 down to 145. pilot jets 38 to 45. and checked float level. needle jet springs fine.

i take for a spin every time i change one thing with same results. "Bogging under braking and quick acceleration.
jets are clean. carb is clean. ngk br8.
i cant seem to fix it with all the great advice.

2001 kdx 220. rev pipe. boysen reeds. powercore silencer. air box snorkel removed.
i live in ontario canada.

More fuel problems

Posted: 02:11 pm Sep 03 2017
by cornishwrecker220
I would check the float height & also the needle valve ( possibly worn tip or dirt )

Also check the jet block gasket .

Re: More fuel problems

Posted: 05:38 pm Sep 03 2017
by KDXGarage
I am suspecting floats. What else would be affected by sloshing??

Re: More fuel problems

Posted: 02:25 am Sep 04 2017
by John_S
At this point after looking back through your other fuel related posts I would replace the float valve no matter how good it looks. This may sound silly but next time you're in there make sure your floats float. Like in a bucket of water. Also submerge them and make sure no air bubbles come up. A hairline crack in a float could drive you nuts.
If the bike dies when you shake it concentrate on the float, float valve, and petcock for now. Next time you measure the float height, measure both sides. Sometimes the metal is tweaked and one float is sitting different than the other one and could be throwing it off too rich or too lean. Maybe the main screen of the petcock isn't flowing good. Try flipping it to reserve and seeing if that changes anything.

When it dies from shaking it or bogs under hard acceleration does it sound like its loading up rich or running out of gas lean? I'm thinking a new float valve is going to fix it.

More fuel problems

Posted: 05:59 am Sep 04 2017
by Greatbrit
it feels like it runs out of gas when i shake it. i will try out tthe things you said
Thank you.

Re: More fuel problems

Posted: 06:25 am Sep 05 2017
by jaywylie
i second the float as a culprit

Re: More fuel problems

Posted: 10:23 am Sep 05 2017
by Greatbrit
Took floats out. no cracks. submerged in water all good.
made sure they are both level.

Should the tang have a bend in it?.
when the carb is completely upside down should i be able to depress the sprung needle or should it be completely closed with no play.
There are no videos whatsoever of KDX 220 float adjustment. There arent even any close up photos of how the tang should sit.

I know to tilt the carb so the tang is just touching the needle and measure. but when the carb is upside down should the floats be level with the mounting surface with play in the needle float spring?.
thanks.

Re: More fuel problems

Posted: 10:46 am Sep 05 2017
by david
The weight of the float is greater than the little spring in the needle can support, that is why you measure it at an angle.

I had to set mine at 18mm to make sure there was enough travel, because at 16mm my float was resting on the body of the carb.

Re: More fuel problems

Posted: 02:38 pm Sep 05 2017
by Greatbrit
i noticed that when the bike is idle and i turned the fuel tap off it idled better straight away. evwn when i shook the bike it didnt die. would this mean its too rich when the fuel is on then? floats are also set right.

More fuel problems

Posted: 03:13 pm Sep 05 2017
by cornishwrecker220
Does the bike leak fuel out of the overflow when it's on the side stand & tap is turned on?
If not then then how far can you lean the bike over before fuel starts to leak ?
It its between 45 & 90 degrees then the level is in the correct ball park...if it leaks when on the stand then the float is slightly too high...

Do you have a buddy with a kdx who can let you borrow his carb for a swop & see ?

Try the jet block gasket .... It may be shot !

Re: More fuel problems

Posted: 04:15 pm Sep 05 2017
by Greatbrit
no it doesnt leak on the side stand woth tap on. will try the lean bike test and let you know. i dont know anyone around me with a kdx unfortunately

Re: More fuel problems

Posted: 04:30 pm Sep 05 2017
by david
Greatbrit wrote:i noticed that when the bike is idle and i turned the fuel tap off it idled better straight away. evwn when i shook the bike it didnt die. would this mean its too rich when the fuel is on then? floats are also set right.
This means that the float is not closing the fuel valve all the way. Set the float to 18mm and try again.

Re: More fuel problems

Posted: 10:22 am Sep 06 2017
by Greatbrit
Set to 18 now. same. bike dies when i shake it. no fuel comes out when i tip the bike 45 degrees either. jet block gasket looks ok but will replace

Re: More fuel problems

Posted: 10:38 am Sep 06 2017
by david
Something is not right. Either your float is heavy and needs replacing, the inlet needle is no good, or the jet block gasket isn't sealing properly.

Re: More fuel problems

Posted: 11:26 am Sep 06 2017
by John_S
I'm still betting on the new float valve fixing the problem. Try this also......


The polishing starts at 1:12 in the video



Our float valve seat doesn't remove like the Mikuni he's working on but you can do the same thing and then shoot it out with carb cleaner and compressed air.

Re: More fuel problems

Posted: 12:18 pm Sep 06 2017
by david
John_S wrote:I'm still betting on the new float valve fixing the problem.
And you may be right. The fuel is definitely getting into the bowl when it shouldn't. The tell is that the idle picks up when the petcock is turned off. And an FYI, testing a float in water is not a good indicator, you need to put it in gas.

Re: More fuel problems

Posted: 12:26 pm Sep 06 2017
by sthutch
That's a great tip! Thanks for posting.


Sent from my iPhone using Tapatalk

Re: More fuel problems

Posted: 01:31 pm Sep 06 2017
by Greatbrit
does anyone have a picture of a side view of the float assembly close up. i wanted to see how straight everything is. i think mine is a bit twisted or at the wrong angle right where the pin goes through and i cant post a picture on here.

Re: More fuel problems

Posted: 08:13 am Sep 07 2017
by david
Mines all put together, sorry. But this ebay listing gives you multiple views. http://www.ebay.com/itm/FITS-Keihin-Flo ... uE&vxp=mtr

I use taptalk on my iphone for posting pictures, it's super easy.

Re: More fuel problems

Posted: 10:41 am Sep 07 2017
by Greatbrit
david wrote:Something is not right. Either your float is heavy and needs replacing, the inlet needle is no good, or the jet block gasket isn't sealing properly.

i have replaced the float needle. i looked at the jet block gasket and it seems pretty flattened out. I cannot find anywhere that sells them in Canada. jets r us wont ship here. The guy in the netherlands is out of stock and every dealer pic of the carb doesnt show the gasket. Anyone know where i can get one. This is getting insane .