Sputtering in 1st and 2nd!

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Dewey
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Sputtering in 1st and 2nd!

Post by Dewey » 06:05 pm Aug 13 2007

New guy here! This is a great site! I recently bought an 02 KDX 220 after deciding to get back into riding bikes, 25 years after giving up my MX racing dreams. So far I am loving the bike for trail riding. My concern is when just playing around in an open field, I take off and nail the throttle, it seems to sputter and not hit the powerband in first and second gear. Once I hit third gear it comes to life and winds throught the rest of the gears fine. In the woods and putting around the yard it has great throttle response and performs well (Thanks to the Boyensen Power Reeds, best $38 spent) but it just seems like it never comes to life in 1st and 2nd when taking off fast. Someone told me that is just the way they run, but I am having a hard time buying that. I know these bike are geared low and I switched to a 13/49 sprocket setup which really woke things up.

Is this normal or is it possibly a jetting issue? Is the powerband that narrow on these bikes . I grew up on MX bikes that would wind until your ears bled! Any help would be appreciated, my last bike was a 79 YZ250!

It has a fresh wiseco piston and rings, gnarly pipe with powercore II and Boyensen Power reeds.

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Dewey
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Post by Indawoods » 06:12 pm Aug 13 2007

Welcome to the site Dewey! :supz:

Could be the pilot jet is too big... could be the needle position... could be a dirty filter.... could need the air screw adjusted.

I would start with the easy stuff first to make sure you are starting off on the right foot. Air filter, air screw. Then raise the needle by 1 clip position. Then spend a few bucks on some brass.... smaller by one size I imagine should do it....
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Post by canyncarvr » 02:25 pm Aug 15 2007

Re: 'Someone told me that is just the way they run..'

Whoever told you that doesn't know what they are talking about.

I'm writing just to second what Inda said. It's likely a jetting issue.


Re: 'I know these bike are geared low and I switched to a 13/49 sprocket setup which really woke things up.'

Presumeably you changed from an OEM final drive setup of 13/47..in which case you lowered the gearing with the use of 13/49.

'Low' gearing gets you low top-end speed. 'High' gearing gets you high top-end speed.

A larger rear sprocket drops your top-end speed.

It's a fairly common practice to use a 12 tooth countershaft sprocket on the KDX. That's moving in the same direction as using a larger rear sprocket. It's cheaper than changing the rear sprocket..easier, too. AND..you can change back in a couple of minutes if you want to.

Winding 'til your ears bleed' isn't going to be a problem with the 220. Well, not with the 200 either.

The 220 is noted for its lack of top-end. It has a relatively small carb in its OEM form. Porting (angle/timing) is considerably different between the two bikes (220/200)..the 220 not lending itself to ear bleeding.

Oh...which pipe do you have? The term 'gnarly' is nondescriptive in that regard. Both the -30 (rev) and -35 (torque) FmF pipes are 'gnarly' pipes.

..the -30/-35 numbers referring to pipe profiles from FmF that are not always used. The model of the pipe will generally be stamped on the top mount tab. One way to know for sure...the -30 pipe measures about 14" in circumference at the bell, the -35 measures about 11".

WHICH pipe you have matters in regard to jetting AND what you can expect in the way of your bike's performance.

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Welcome back to riding, too!!

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Post by Dewey » 12:10 pm Aug 22 2007

Thanks for the info guys!

This bike had a 12/47 on it when I bought it, and I thought that was the OEM setup. I like the 13/49 for most of my riding, but may switch the front back to a 12 if I ride in some really rough stuff.

I guess I have the rev pipe, I couldn't find the number but it measures close to 14".

Anyway, I check the jetting and it had a 50 pilot and a 140 main. This seems weird to me! I am thinking of starting with a 42 pilot and a 145 main to see how that does. Does that sound like a good starting place with my setup?

I am think of doing the R&B carb and head mods this winter, has anyone done this? Does it hurt the low end?

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Dewey
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Post by m0rie » 12:16 pm Aug 22 2007

The 42 pilot and 145 main should be a good starting point. The 50 pilot is way to rich for sure. RB carb and head mods are a nice upgrade. Get your stock carby jetting right first though so you know what your getting.
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Post by canyncarvr » 12:45 pm Aug 22 2007

I am think of doing the R&B carb and head mods this winter, has anyone done this? Does it hurt the low end?
Check this!

A second vote on what m0rie said. Your current jetset is way wrong. No wonder there's a sputtering result.

I didn't look through all the posts in the RB forum above, you may find input from 220 riders there in regard to what they thought was the effect on bottom end. It stands to reason something will change..as an OEM 220 carb is much smaller than the resultant RB'd 36mm. The stranglehold the small carb has on the 220 will be gone. That's a good thing.

Do some carby tuning..that way, like m0rie said, you will know exactly what you got with an RB modified carb.

The -30 pipe is the choice of most 220 riders. Get that 50 pilot out of there..and you will be impressed with the improvement.

Happy tweaking!

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Post by Jeb » 05:46 pm Aug 22 2007

Welcome to the site Dewey! Where are you from?

we got a few things in common - I got into MX back in those days as well ('81RM125 then an '83YZ250) and only last year got back into riding.

And like you I got the 220 and spent some time dialing in the jetting before I "got RB'd" (yes, like a religious experience). Right now though, if you're anywhere near sea level (say 1,000 ft or less) I'll bet you'll end up with either a 142 or 140 MJ and a 40 maybe even a 38 PJ. You should be pleased with the results. Read about throttle chops and use that as your measure of where you stand with the jetting (there are some recent threads that are pretty good). It'll be time well spent. You've got a great start with the mods you have, optimize with the right jets for maximum grin factor.

RB mods - get 'em! You're looking at $225 for both the head mod and the carb mod. You've got a great bike, the mods will make it a fantastic bike.

BTW - they'll never admit it but the 200 owners are jealous of us proud 220 owners! :wink:
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Post by 2001kdx » 06:04 pm Aug 22 2007

220 is junk... Name a good reason why Kawi made the 220 - The stock piston is known to grenade, the power is, and i'm speaking in a general state of mind, nearly identical to the KDX200, the bike is the same in almost every way. Oh yeah and the 220 is SLOWER than the 200. (stock)

You 220 guys sure do got it made!

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Post by canyncarvr » 06:46 pm Aug 22 2007

..they'll never admit it but the 200 owners are jealous of us proud 220 owners!
That is a fact.

But then, my particular list of psychoses includes: Yearning to be poked fun of, left behind on every straight section over 25 yards long, and a deep desire to have my bike boil over every five minutes.

Maybe it's just me. :wink: (I say...thassa joke, son)


...and they come with an o-ring chain!! YiPpeE!! :rolleyes:

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Post by Jeb » 07:15 pm Aug 22 2007

I can't think with all that 25-yard-long psychoses, "two-hunny" chatter . . .

BTW, I've never figured out the whole "boiling over" thing, that's never happened to me. It was quite warm this past weekend and I ran my sweetheart-of-a-woods-weapon-220 pretty hard for a good bit of an afternoon. What's the issue?
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Post by canyncarvr » 07:20 pm Aug 22 2007

The issue, apparently, is that any time a 220 is made to work (I mean really..as opposed to 'pretty')...say it's trying to keep up with a 200...it spits.

Of course...once all the spittle is removed from the spittle containers (rads on a 200)..it doesn't spit no more. Some might think it's simply not getting hot..............


'MOM...HE STARTED IT!!'

they'll never admit it but the 200 owners are jealous of us proud 220 owners!

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Post by IdahoCharley » 07:41 pm Aug 22 2007

>|<>QBB<
canyncarvr wrote:The issue, apparently, is that any time a 220 is made to work (I mean really..as opposed to 'pretty')...say it's trying to keep up with a 200...it spits.

Of course...once all the spittle is removed from the spittle containers (rads on a 200)..it doesn't spit no more. Some might think it's simply not getting hot..............


'MOM...HE STARTED IT!!'

they'll never admit it but the 200 owners are jealous of us proud 220 owners!
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Post by Jeb » 08:04 pm Aug 22 2007

:roll:

Honestly, Mr. Dewey, those 200 guys really ARE "pretty" good guys even if they do get a little excited now and then . . .
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Post by Dewey » 10:26 am Aug 23 2007

This minor bickering is pretty funny to me considering the 200 and the 220 have about 95% of exactly the same parts. Can't we all just get along!

I have ridden Honda's, Suzuki's, Yamaha's and Kawasaki's of various MX 125s & 250s, Husky WR360, Honda 600r. I have never ridden a bike that I would call junk at the time, well other than Harley's attempt at a MX Bike.

I have found that matching the bike to the rider is the trick. Back many years ago when I was riding a tricked out YZ250, I rode some trails with a guy that had one of the new "great" KDX 175s. We switch bikes and rode about 2 miles before we were ready to switch back. His eyes were the size of half dollars and he was shaking all over. I was laughing and asking him why he didn't get a real dirt bike. The funny part was we rode really well together, of course I could run off an hide from him on some trails and on others he would stop and wait at the top of hill for me to finally find a line that I could get up. The moral of the story is the same bike doesn't fit every one. I loved the WR360 for playing around on , but I wouldn't want to ride it in tight woods and it was a pain to start. If my 220 doesn't start on the first kick I start think there may be something wrong with it.


Now I am a lot older and a little slower and I really like my 220, I can't say anything about the 200 because I have never ridden one. I am sure they are great bikes, but I was looking more for low end grunt since most of my riding is in tight woods. I figured I would get a bike to match my weight 1 cc/lb seemed to make since. I am in south central TN and where we ride, if your not bouncing off of trees, your trying to get up some rutted, rocky hills, or through a creek. Even with the 13/49 gearing, it has plenty of low end and I don't have to shift gears so much when playing around on open trails.

Anyway, I worked on my jetting last night. I am currently at 40 pilot and 140 main, needle in middle groove. This thing is really coming to life now. No ear bleed but a slight boner. It is still a little off on the first 1/4 throttle (but who uses that :-) and I am working with the screw, but I am thinking a 38 pilot may be in order. Right now we are averaging 102 & 103 degrees with 70% humidity so I will probably wait for it to cool off some for fine tuning.

Now if I can just get rid of the green plastic. I like Kawasaki's just fine but I hate the ugly green. Anybody got a black tank they would part with?

Thanks for the info and conversation
Dewey
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Post by fuzzy » 11:19 am Aug 23 2007

Will definitely require an abnormally lean jet-set in conditions like that! Of course there will be noticable lack of power in that air as well. Wait til it's 60 out!
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Post by Jeb » 05:37 pm Aug 23 2007

>|<>QBB<
Dewey wrote: . . . Right now we are averaging 102 & 103 degrees with 70% humidity so I will probably wait for it to cool off some for fine tuning . . .
wise choice . . .
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Post by canyncarvr » 10:01 am Aug 24 2007

Bicker leads to quarrel....

Quarrel leads to dispute....

Dispute leads to..'A disagreement about something important'.

So...we now know there isn't any bickering going on. I mean...bickering doesn't entail facts..true facts...and absolute facts stated.

Whew...I feel better.

95% the same parts? Yep. A 2400cc pinto has a camshaft..my Duster has a camshaft. Heck..same parts!! Wanna race?

Seriously, you may not realize the difference between the 200/220 is NOT simply 20cc. Yeah...they both have pistons..but they sure aren't the same engine!! Not even close.....

Anyway...all in good fun.....

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Post by Dewey » 12:36 pm Aug 24 2007

That Duster got a Hemi?

I got to try one of those 200's, as I said, I've never ridden one.
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Post by canyncarvr » 01:29 pm Aug 24 2007

Nope. No hemi. :sad: It's got a '69 X-head 340, though!

Re: 'This thing is really coming to life now.'

The 220 has a 33mm carb. Send it (and the head) off to Mr. Black..and it'll come back a 36mm. THERE'S some 'coming to life' for 'ya! Get one'a his knurled-knob air screws to allow easy adjustment to the modified low speed circuit (from RB..part of his modification package), find the SSS (Second Sweet Spot)..and you will 'come to life' even better!!

It'll never be a YZ250. It won't beat you up like a YZ, either (suspension mods notwithstanding).

Yeah...the 200/220 are more alike than they are different. They ARE both kind'a green...well, 'cept for maybe the newer silver-framed black-tanked jobs. You're '02 is green all over (- side plates)?

Oh..if Mr. Black is going to send your carb back with a CEK...order up a DEK to come back with it, too. Two quite different 'personalities' on the KDX. Maybe put an e-clip on that order, too (clips from your local hardware store don't fit) so when you try to put it on and it goes ZZ-III--NG...you won't say HeySOOS in an overloud, exasperated tone.

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Post by Jeb » 05:18 pm Aug 24 2007

>|<>QBB<
Dewey wrote: . . . I got to try one of those 200's, as I said, I've never ridden one.
Do try one, chance permitting . . .

Having ridden one (actually two), I would agree on differences although I personally can't echo the "not even close" part. The 220's juices get flowing earlier while the 200 still has some left when the 220 starts winding out. Modifications change that considerably; in fact, that rev-profile pipe like the one you have extends the upper range closer to that of the 200.

My "comparison" experiences were between a rev-piped 220 and a torque-piped 200. Personally I didn't feel a whole heck of a lot of difference.

Of course, nothing beats your own experience so try one out. For the "tight woods" you described, you'll appreciate your 220.

One thing's for sure though: either KDX is one heck of a bike!!
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