01 KDX 200 Carb problems

[BigJack]

Well just did a nearly complete engine rebuild due to a bad connecting rod bearing. When I got the bike back together it fired right up on the first or second kick. The problem I'm having is when the fuel selector switch is in the on or reserve position fule runs out of the drain tube at the bottom of the carb. I filled the tank up with 2 gallons of premix and got about 20 miles before I ran out of gas. Now I was on the throtle a little but that is terrible gas mileage. Any idea what I should look for? What is that tube for? A vent?

 

[Aflica]

That tube is not a vent , but the over-flow for the float bowl. Your float is sticking , you should check the float needle for wear or grooves in the rubber top , and replace if nessesary and adjust the float height. This is common. Hope this helps

 

[BigJack]

Thanks for the reply. Yeah I've been told by several people that's probably a stuck float. Well I took the carb off and start taking the loat bowl off and every screws loose. They were not even finger tight. Also the float bowl drain bolt was hella loose too. This is a new bike for me and I'm just finding all the problems. I checked the float and float needle and all the seals and everyting looks good. I guess it just came loose or the previous owner didn't tighten them well. I put the carb back on and turned the gas on and watched it for about five minutes and didn't see and fuel leaking. I'll have to give it a test ride tomorrow. Hopefully that was it.

 

[BigJack]

Ok I checked the float needle and it looks good. The float height also looked good. I think I've stopped the leaking by tightening the float bowl screws. Now I have a new problem. Bike will start on the first kick and and idle high with choke on. When I turn the choke off idle is still high and starts to rise. I've got the air screw turned out 1 1/2 turns oer the manual. The idle stop screw is turned out several turns and had no effect on bringing the idle down. The bike will run with a high idle for about 4-5 minutes and then die. After that I can not start it for about 30 minutes. :bang: What should I check? Thanks for any suggestions.

 

[andrew]

sounds like it's running really lean. Mine does that when I run out of fuel. Could you have jammed the floats so that not enough fuel is getting through? I assume the fuel tap is on?! Either that, or you've got a massive air leak somewhere, which doesn't sound likely, if it's just the carb you've been playing with. What about the clamp for the intake boot - is that tight?

Andrew

 

[John Harris]

I think your bike is starving for fuel. Runs the carb dry, racing and lean and then dies. Do you have an in-line fuel filter? If so try without it. If you still have the problem, drain the tank and remove the fuel valve to check the strainer/filter in the tank. Maybe the fuel level is very low in the tank so try it on reserve first before you do anything else. Cheers John

 

[Green Hornet]

Check for an air leak. Is the carb intake boot-AKA: Manifold (Rubber between the carb and head) cracked or tight enough? When you start the bike up (COLD ONLY) spray some carb cleaner around the manifold and listen for a change in engine speed.

 

[kx200]

Also check your throttle cable for enough free play

 

[BigJack]

Ok I've checked for air leaks with a can of starter fluid. No leaks. The cable is fine too. If I pull the fuel line off the carb gas pores out so I think I'm getting fuel to the carb. I'm thinking I have a clogged jet somewhere. :yikes: I'm gonna take the carb off and clean it real good.

 

[BigJack]

Well i took the carb off and took it apart and thoughly cleaned everything. I reassembled it and made sure the float height was correct. The clip for the needle jet was on the lowest position. I would think that would make it too rich so I moved it to the middle position or 3 up. I put the newly cleaned carb back on th bike. Bike fired right up on first kick. After a few minute warm up I blipped the throttle and it revved nicely. I tested it on the road and it has a lot of hessitation under load. I don't get it. revving in neutral it sounds great but in the gears it bogs. :bang: Anybody???

 

[andrew]

yeah mate, under load is where you really sort out the jetting. It sounds like it's too rich. Go one size leaner on the main jet and see if it improves. As a guide only, at sea level - 1000ft, I am running a 155 main and a 42 pilot. It is just a shade rich (as evident from a small amount of spooge at the tailpipe) but it doesn't bog under load. Standard is two sizes larger on the main at 160, and I think a 48 pilot (again two sizes larger than mine). If yours is still standard, buy a small range of jets and start testing!

Cheers,
Andrew

 

[Rhodester]

What's your current jetting set up? What is your elevation, temperature you're operating at, and any modifications (reeds/reed block, pipe/silencer, air box lid mods)? Try riding in the trouble spot range with the choke on (once the engine is fully warmed up)....does the hesitation get better or worse?

 

[BigJack]

Current jetting should be stock. I know the main jet is a 48. I can't remeber the jet needle but the clip was on the lowest position. I put it in the middle position and haven't noticed any difference. The bike came with a aftermarket power reed, a gnarly pipe and fmf silencer. I am at sea level. So where should I start? Thanks....

 

[andrew]

Current jetting should be stock. ... So where should I start? Thanks....

start with a 158 main and a 45 pilot.

If it is still too rich (ie bogs, lots of spooge), go to a 155/45 or 155/42. experiment with needle clip position. clip at the bottom (where you said it was) is richest. If you don't like the 45 pilot with the clip at the top, go for the 42 with the clip near the bottom and try different positions till it's the way you want it.

Andrew

 

[Rhodester]

The stock PILOT jet is a 48. The stock main is a 160 and both are usually too rich.

When you wrote "Current jetting should be stock" and yet the bike has several mods immediately sent red flags up in my mind. I'd be very reluctant to assume that was the case (especially since the needle wasn't in the stock clip position). Again I ask, what is your current jetting? That is where your problem lies.

 

[strider80]

Just for jetting reference, this is what I run and works well for me, it is also recommended on the FMF site:
Sea level in Seattle
Pilot: 45 Main: 152
Needle: 1173L 3rd position
2000 KDX 200
FMF Gnarly rev
Boysen power reeds
air box lid drilled
FRP torque ring

Clean all the jets and the air passages in the carb(the holes visible on the carb inlet side) with carb cleaner. Either your jetting is way off, or you have a clogged jet/passage.

 

[BigJack]

I'll have to check the jetting again. I just cleaned it real good and put it back together. I say the jetting was probably stock because it seems like the previous owner had no idea what he was doing. Most people are afraid of carbs. I'll tell you what though, it starts on the first kick cold and it pulls like hell once you get out of the low rpms. It just seems to bog alot down low.....

 

[lepper]

Sounds like a lean bog to me....

 

[BigJack]

OK tore the carb apart again and actually took notes on the jets. :)

Main - 162
Pilot - 48
Needle - R1174K/2AF Clip in 3rd position from top or bottom.

As stated before I am at sea level, high humidity and high heat. I have a FMF Gnarly pipe and FMF silencer and an aftermarket reed but I'm not sure what brand, stock airbox with a uni filter. I'm guessing my jetting is a little off. I've cleaned the carb thoughly and made sure all jets were clear.

 

[BigJack]

Well I'm taking it to shop today if I can't figure it out. Thanks for the help guys......