Jetting recommendations for a 90 KDX200 (california)

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cleoent
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Jetting recommendations for a 90 KDX200 (california)

Post by cleoent »

Hi everyone!

I live in california, just bought a relatively stock 90 kdx200. It has a fmf fatty pipe, stock silencer, and i'm planning on throwing a uni into it and pull the snorkel.

Anyone have any recommendations on what i should do with the carb? Pilot size, jet size etc? It smokes quite a bit right now, i haven't opened it up yet, supposedly has a fairly fresh top end.

Thanks in advance :butthead:
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Post by m0rie »

Welcome to the site!!!

I'd pull the carb and verify what it has for jetting, but the stock jetting for a 90 KDX 200 was a 150 main and 48 pilot. You'll most likely want to drop the pilot down to a 42 to start with. The 150 main should be fine. You'll want to pull the snorkel off the airbox lid and pull apart the silencer and check the condition of the packing. What oil and mix ratio are running?
1989 KDX 200
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Post by cleoent »

I'm running 40:1. I dont know anything about pulling apart a silencer and checking the packing, is there a write up i could look at?
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Post by m0rie »

I don't have a write up but the stock silencer is pretty easy to disassemble. Just remove the bolts on the outside and start tapping/pulling it apart. Clean all the good and carbon that you find up and check the wool packing inside. If its saturated your going to want to get some packing to replace it with.

Here is a picture of it:

http://www.buykawasaki.com/Scripts/ImgS ... F=P&ilRE=8
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Post by cleoent »

Put a new air filter on, repacked the muffler and changed out the jets today. Jets were stock ones it looks like, 160 main, 50 pilot :shock: Maybe the CA modles were jetted differently???

Or the previous owner mucked it up.

Either way, i honestly can't believe what a difference this has made. I thought before that the bike was suppose to have no top end because the motor is built for trails, boy was i wrong. Instead of flat lining it just keeps revving!!! Awesome!
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Post by m0rie »

Yeah that jetting would really screw it up. What did you end up putting in it? Might want to pull the pipe and see if its carboned up at all. Was the packing in the muffler pretty saturated?
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Post by cleoent »

>|<>QBB<
m0rie wrote:Yeah that jetting would really screw it up. What did you end up putting in it? Might want to pull the pipe and see if its carboned up at all. Was the packing in the muffler pretty saturated?
ended up putting in a 45 pilot, 155 main. What are your thoughts? I picked up a 152 main, and a 150 main, but 45 pilot is all i could find.

nor cal here we're having 80 degree days, mild elevation.

The inside of the silencer was COMPLETELY saturated, it was disgusting.
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Post by cleoent »

btw can you take a pic of the needle clip thing that i have to change? I have no idea what you are talking about... :(
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Post by m0rie »

Look at picking up a CGK needle from sudco to replace the lame stock kawi needles. Run it in the #1 or #2 clip position with a 152 main and a 42 pilot to start. You'll like the difference. You might want to check the condition of the reeds. If you see any chips, frayed edges or they don't seal tightly against the reed cage then you are going to want to replace them. Also if they have the stock brass duck bill reed stops on they are most likely the original reeds and should be changed.
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Post by m0rie »

I'll see if I can dig up a picture of the needle/slide assembly here in a bit.
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Post by cleoent »

you dont think 152/42 will be too lean?

Where should i order all this stuff from? Would like to avoid going over to the dealership.. and the sudco site looks very confusing/intimidating.
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Post by m0rie »

I've never bought from this place before but their prices look okay and the selection is good for jets and such.

http://www.dgperf.com/keihin/Keihinprod ... =76&Model=

I've run a 150/40 combo with the CGK in the #1 clip position @ 100ft on the coast before so a 152/42 should be okay to start with.
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Post by cleoent »

thanks :)

Will leaning out the main jet and pilot provide an ever bigger performance leap? What should the air screw be set at?
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Post by m0rie »

You'll find a little more performance, the pilot is the one that really needs to drop in most cases. You can run the main a little fat and not have any issues but reduced mileage. You'll find there is a large difference between the CGK needle and the stock kawi one. Set the air screw @ 1 turn out from close to start with and tweak it until you find the spot where throttle response is best.
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Post by m0rie »

Once you get the jetting set right so your not fouling plugs left and right you might give an EG plug a try. Stay away from the stock 9 heat range plugs as well. You want to run a 8 range plug if your not already.
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Post by cleoent »

i haven't fouled any plugs yet.

And i have no idea what plug i'm using. I'm new to the whole two stroke thing... :)
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Post by m0rie »

The stock plug for an E series KDX (89-94) is either a NGK B9ES or NGK BR9ES. Both of which are two cold of a plug to burn off the deposits on the plug in most situations. For this reason most people run a B8ES or BR8ES which is a one step hotter plug and burns those deposits off better. The B8EG and BR8EG are what NGK calls their racing plugs. They have a smaller fine tip electrode which makes for a better spark in some situations. The real reason to use it is there is a little more low end pull in situations where the bike might otherwise stall without it. Not a bad improvement for $3. But its best to get your jetting sorted out with the cheapy ES plugs first. BTW the R stands for resistor and from 90+ they used the resistor plugs instead of the non-resistor plugs.

Does that help?
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Post by cleoent »

it sure does!

Any information on the xr400 spring swap?
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Post by m0rie »

I'll finish up my PM to you here in a bit.
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Post by cleoent »

got the PM thanks.

I'll probably have more questions regarding that once i get the parts. What are the springs worth anyhow? 20 bucks? from a 98 xr400.

I picked up a 42 pilot today and a 40. I also picked up a cgk needle.

Hopefully have results for you today or tomorrow.
1990 KDX200, 2007 KTM 200XC, 2004 TTR125L
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