Sputtering at low RPM

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GS
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Post by GS »

""Wonderful info guys, now I understand. The bike is as I mentioned a 2001 with original front tire, sprockets and chain. I know the fellow personally and he babied the bike. Was $2200 Canadian too much?""

Well, I spent $2,500 on my '99 ....4 yrs ago.
And the guy was a really willing seller at that time. No mods at all, either.

They are priced higher in Canada....because we know what the dang things are worth!!

......and our dollar is in the toilet.....
lemmy
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Post by lemmy »

I spent $1600US on my 2003 6 months ago (racetech work front and rear, no toil air filters, RAD valve, PWK35 carb, aftermarket seat, aftermarket bars, acerbis bark busters). At the time I thought it was an ok deal but now I know it wasn't. I had to do lots of work and some money to get this bike running right.
Kurt Franz
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Post by Kurt Franz »

>|<>QBB<
fuzzy wrote:Looks interesting
If any gives a hoot.........

I emailed Jeff Fredette about this a while back and he told me that it is a pilot jet issue - plain and simple.

I have been out of commission for a while now but am now going to address this. I need to get this thing running smooth in 1/8 throttle in 5/6 gear mode.

My bike is completely bone stock. I will reply with my results when they are in....as a public service to all.
1987 BMW K75
1973 Yamaha CT3
2004 Kawasaki KDX200
1981 Yamaha PW50
dubtruker
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Post by dubtruker »

I use my KDX on the street with Supermoto wheel setup and old FMF gold series pipe and Boyesen Rad reeds. It has 15/38 sprockets on 130/70 17 and rips around town, however on highway it is happy cruising at 100km/hr but try to cruise any higher and it does what you guys are talking about. Mostly on my short highway jaunts I will pin it in 6th to bring it up around 145Km/hr and it doesn't surge but I fell bad about pinning it for long periods of time. I am new to the bike but I am glad I read this, I geuss its running right. By the way, Hello fellow Newfie born and bred and hello to fellow Vancouver habitant. :supz:
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canyncarvr
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Post by canyncarvr »

The following:
Hey guys,
Thanks for all the advice, the bike is doing what kurt said. When cruising at 1/4 throttle its sputtery, a little more throttle and its ok. Idles fine and Otherwise the bike runs great, you call this 4-stroking? I had a 1994 kx 250 that did the same thing, is this normal for a 2-stroke?
..is not a pilot jet issue, plain and simple, even.

It's what 2Ts do when not under load. It's four-stroking.

If you 'succeed' in jetting that burble OUT of your bike, it at the least won't run for diddle performance-wise and will likely stick itself.

My bike chubbles as described..in 6th gear..running about 45-50mph..a bit under 1/4 throttle. I'm running a 38/148 jet combo. Someone wanna tell me my pilot is too rich? :roll: But, I run a 12/47, too.

15/38 sprockets on 130/70 17? I would be surprised if you could GET to a 'no-load' situation with a setup like that. That's WAY tall.

Consider the source
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fuzzy
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Post by fuzzy »

Indeed.

The real fix for a road bike would be a CV type carb with an air-cutoff. Direct pull slide carbs, and a big expansion chamber are simply going to do this. While the KDX is a mild torque monster in the world of 2-stroke bike motors, it's still ALL GO. :mrgreen:
'91 KDX 200 Project $300 KDX
'95 KDX 200 Project $600 KDX
'94 WR 250 Always a project
dubtruker
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Post by dubtruker »

>|<>QBB<
canyncarvr wrote:
15/38 sprockets on 130/70 17? I would be surprised if you could GET to a 'no-load' situation with a setup like that. That's WAY tall.
Yeah the 38 came pre-installed on the Japanese D-Tracker wheels. I was sure it would be too tall but was experimenting to see where I needed to be. Turns out it just plain rips around town and is great for short high speed runs. Feels as good all around as my old DRZ 400 supermoto.
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canyncarvr
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Post by canyncarvr »

Where's the pics?

Re: '......and our dollar is in the toilet..... '

Well...oh YEAH! :twisted: Our $ terlit is bigger'n YOUR $ terlit!

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Jonooffler
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Post by Jonooffler »

Hi mate I wish I had found this a few days ago I have a 2003 KDX220 and it does the same thing it is a real pain. I have changed the pilot from a 42 to a 38 which was a bit better then to a 35 which was a bit better again , most riders will say change to 40-1 mix or 50-1 this will only make the fuel richer which will add to the problem. The air box will not make much of a change.
They are just bad at low revs I hate mine now and wish that I had never bought it ,I'm looking to go back to a 4 stroke.
Jono
Been riding off road for 10 years still finding out how best to do it.Riden a DR125 then a DT125R then a DR125 then DRZ400 then XR250 then a TE610 now I hope that I have found the best a KDX220 just to add the KDX has gone now riding a WR426 which I love and is so much better than the KDX.
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canyncarvr
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Post by canyncarvr »

Re: 'They are just bad at low revs....'

Tune a guys bike, and he'll be happy for a day. TEACH him to tune it...and he'll love it forever.

Re: 'I'm looking to go back to a 4 stroke.'

C'ya!

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