kdx220 will not idle, heavy smoke on decel ?

[s10gto]

I am in Ma. and my 220 is $113 a year for full ins.

[ohgood]

well I spoke too soon.

compression test shows 150psi hot, wide open throttle.

very little smoke now (well, for 32:1)

no drop in transmission fluid level (yay!)


but these symptoms persist, after today's 19 mile test ride:

1) idle is very low, and the idle screw does not effect it, at all.

2)1/8 throttle response is very poor, hesitates, and bottom end power is not like it was before at all.

3) it's very snatchy /boggy anytime I'm not accelerating. it will accelerate, but not like before.

4) air screw makes no difference at all. idle does not increase or decrease with the air screw.

well, where should I stay this time?

[6 Riders]

Re-jet? You put a new top end on it, you should need to jet accordingly.

[ohgood]

Re-jet? You put a new top end on it, you should need to jet accordingly.

OK. so I assume it's rich as heck and go smaller ?

[6 Riders]

Sounds to me like the pilot is to rich, but there could be more to it than that. Use the jetting guide to get it right.

[ohgood]

Sounds to me like the pilot is to rich, but there could be more to it than that. Use the jetting guide to get it right.

fresh top end...

FMF gnarley with woods arrestor...

today I'm trying to get the getting right, I have tried:


(this is the best so far, but still stumbles off idle, mediocre midrange, OK top end, air screw effects this setup)
142 main, 38 idler, 1 1/2 turns out, third position from the top




(what I started with, poor off throttle response, poor low end power, mediocre acceleration, ok top end , air screw does not effect this setup at all)
142 , 42, 1 1/2, third from the top




does anyone think I need to go even leaner on the pilot, or both the pilot and main ?

[KDXohio]

Have you checked for intake air leaks between carb and motor best way to check is with the motor idling spray starting fluid around the boot if your idle changes you have a leak. Seen buddies chase their tail jetting just to find out they had a small crack in the boot or something simple like that

[ohgood]

Have you checked for intake air leaks between carb and motor best way to check is with the motor idling spray starting fluid around the boot if your idle changes you have a leak. Seen buddies chase their tail jetting just to find out they had a small crack in the boot or something simple like that

yes, I used propane, no effect.


today's attempts:
38 idler, 142 main, 1 1/2 , 3rd clip, float at 16.5mm--- bog and die, twenty feet from me driveway


same as above, but with 42 pilot, rode about 5 miles, but still barely isles, no effect from air screw, no effect from idle screw

same as above but with 35 idler, bog and die


...... needle.....
142, 40, 1 1/2 turns out, 2nd clip from the top, lean and ugly, came back home

same as above but second clip from bottom, boggy and poor all around, came back home

the middle clip on the needle is the best position so far.

the 142, 40, is the best combination so far.

I even changed the arrestore to the FMF Rev pipe, and repeated a few keeping changes to try and find a pattern or better setup. no luck.


I'm beginning to think the carb is just junk now, but this isn't logical unless it became junk at the exact same time the crank seal failed, and I find this unrealistic.

I did glue the jet block down, to see if that was leaking and throwing off the process. no change.

any more ideas?

[ohgood]

well, I'm completely at a loss now.

the jet block is sealed all the way around.
the idler jet makes no difference.
the main jet makes no difference.
the air screw makes no difference.
the float level, besides flooding the driveway, makes no difference.
new plugs, no difference.
different pipe, no difference.
plugged the choke inlet, just to see it was leaking, bit of course the bike won't start without the choke.


is there anything else weird about this carburetor i can check?

[6 Riders]

Have you checked to see if the jug and head are still torqued to spec and not leaking? How about good flow from your tank? It sounds like an air/fuel problem, so start at the top and work your way down to the carb. There was a guy on here that was out of gas and fighting stuff like this for days. Once he figured out the PETCOCK is opposite of, say a Honda petcock, he solved almost all his issues.
I'm just saying, check the simple stuff, if your carb is non responsive to anything, then it is not the problem.

[KDXohio]

Make sure your air filter isn't plugged could have a nice mouse nest or something in there restricting air flow

Next I'd look your reeds and make sure they're in good shape as it sounds like you've got another issue that is not allowing you to dial in the jetting

[KDXohio]

here's what FmF recommends for jetting

Jetting Results

Main Jet 145-148
Pilot Jet 42
Needle R1173L
Needle Position 3RD
Air Screw 1.5
Fuel Screw N/A
Comments Remove airbox lid snorkel

[ohgood]

[quote uid=7946 name="KDXohio" ]here's what FmF recommends for jetting

Jetting Results

Main Jet 145-148
Pilot Jet 42
Needle R1173L
Needle Position 3RD
Air Screw 1.5
Fuel Screw N/A
Comments Remove airbox lid snorkel[/quote]


yes, I've seen that. it ran perfectly prior to the seals and top end, with that jetting, but now there is no effect on the air or idle screw, from any combination of jets and/or needle settings. this is what I'm trying to figure out.

[KDXohio]

Have you checked your reeds?
Worn out reeds will have rich symptoms

[ohgood]

Have you checked your reeds?
Worn out reeds will have rich symptoms

Glancing at them through the intake is not "checked" apparently, because that's what I did previously.

Had I pulled the block I would have found this:

see the light in the corner?



now you can



more light


closer


.020" gaps on one side



.020" between reed and block, plus another .020" between the reed and backer




the chipped corner is about 3/16"x1/4", and the reed is frayed around it, along with the backer. one of the guys on dirtrider said that's enough, especially the corners, to give problems at everything except high rpm's, and then it wouldn't run nice either.

sooo, i'll be shopping for a new doohicky this afternoon.


boyson is still considered good stuff in 2015, right ?

[s10gto]

Yes they are good. Check out v force also.

[ohgood]

Yes they are good. Check out v force also.

thanks, I'll do just that

[KDXohio]

That'll do it! I have boyesen pro series in mine i'm about to swap out for a rad valve they've been fantastic reeds only 20-30$ too from memory my intake boot cracked or I wouldn't have bought the rad


With new reeds your jetting should get a WHOOOOOOOLE lot easier.

[ohgood]

That'll do it! I have boyesen pro series in mine i'm about to swap out for a rad valve they've been fantastic reeds only 20-30$ too from memory my intake boot cracked or I wouldn't have bought the rad


With new reeds your jetting should get a WHOOOOOOOLE lot easier.

thanks a metric ton :)

[ohgood]

well, i thought this was the stock reed cage, with a sticker on it:


but since my YAY NEW PARTS just arrived, i see things aren't quite the same:




and now i'm scratching my head, wondering:

a) what the hell do i need to order to replace THIS cage+reeds (the left one):


b) exactly what THIS cage+reeds will fit, so I can sell the damned thing (the right one):



anyone want to fill me in as to what the LEFT cage is called, which bike it goes on, and what the RIGH Tcage is called, and what bike it goes on ?

this isn't even fun anymore. kind of just want to push it in a damned creek at this point.