Carburetor question.

**MonkOFox** · 10-15-2013, 04:58 PM

Ok so I had started up my 200s and it was doing ok. I turned the idle down a bit (counter-clockwise or lefty). But after awhile it would start revving higher and higher. I would turn the screw out more, but wouldn't really change anything. Also, I would turn the fuel mixture screw in and it would never die down for me to tune it.

What could be the issue? Or am I over looking something simple? I cleaned it too. Maybe I should take it all apart and soak them for a longer period of time?

**yaegerb** · 10-15-2013, 05:00 PM

is the air/fuel screw adjusted to OEM specs? Have you checked for air leaks around the manifold?

**dougspcs** · 10-15-2013, 05:08 PM

Have you cleaned your carb?

Is your engine compression within spec?

Have you adjusted the valves and checked the ignition timing?

Lots to look at here!!

**MonkOFox** · 10-15-2013, 07:49 PM

Oh ok I have a head gasket leak. Guess that could be causing the issue.
That makes sense. Guess it's sucking in more air through the leak on the intake stroke.
It says if I tighten the throttle stop screw (air pilot?) that it should eventually die. And then to turn it 1 turn out and re-adjust.
That never happened, ever. Also the engine never slowed when I turned the fuel pilot in or out...

I figured even if it was off a little (due to the leak) those things would still happen.

**JustEnough** · 10-15-2013, 10:22 PM

If the slide spring came from another carb, it may be a little short, allowing the slide to float up.

**MonkOFox** · 10-16-2013, 09:10 AM

I'm not sure (it's been a while since I bought it) but I think the aftermarket carb came with a new slide/spring/needle/screw cap.

**dougspcs** · 10-16-2013, 10:18 AM

Monk..you are kinda all over the place and firing shots wildly into the air.

1st head gasket leaks causing tuning problems are more typical of a two stroke engine, not a 4 stroke..

Get down to the basics as Yaegerb and I have listed for you..

Then do a dry/wet compression test to see where the engine health is..then move into air leaks, valve adjustment and ignition timing.

Lastly a second poke at that carb cleaning, you really need an air compressor to blow out the ports!! Use the manual for instruction on proper carb setup..

You answer is somewhere in there..

Besides you standard hand tools, feeler gauges, small air compressor, and engine compression tester really should be in your arsenal!

**MonkOFox** · 10-16-2013, 10:27 AM

Yeah I'll tear it down and clean it again (carb). I'll do those things in that order. Thanks for the guidance : ).
I have everything you listed except the compression testing device.

**JustEnough** · 10-16-2013, 10:39 AM

If you have the old carb, you may want to try the cap and spring that is on it. It is possible that the chinese carb has the original Keihin cap, spring and slide, or parts thereof. The surface of the chinese carbs is rough, which helps to tell which is which. I used to swap parts with the various model carbs, but I have found slight differences between the Keihin models, and the chinese stuff is often way different.

As you can see from this document, each model may have different jet sizes and settings. I use this document as a reference for the chinese carbs as well:

http://farm6.static.flickr.com/5019/...bfc676cd_b.jpg

**MonkOFox** · 10-16-2013, 11:26 AM

Awesome, thanks for that image. The 'Fuel Inlet Valve' that hangs from the 'Float Adjustment Tang' does it matter which way you hang that? By this I mean, there is a tiny wire that it uses to hang but its bent forward at an angle. Below is a diagram of the inlet valve and the way I have it currently installed:

Click image for larger version.

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**dougspcs** · 10-16-2013, 11:55 AM

Originally Posted by MonkOFox

Awesome, thanks for that image. The 'Fuel Inlet Valve' that hangs from the 'Float Adjustment Tang' does it matter which way you hang that? By this I mean, there is a tiny wire that it uses to hang but its bent forward at an angle. Below is a diagram of the inlet valve and the way I have it currently installed:

The little tip you are referring to should be straight and spring loaded and no it doesn't have to be pointed in a certain direction..

That doesn't look right to me, but then again maybe the Chinese carb is designed that way??

**MonkOFox** · 10-16-2013, 12:08 PM

Awesome, just wanted to make sure. That's the only thing off the top of my head that I wasn't really sure about when I cleaned it the first time.

**Jwmajic** · 10-16-2013, 02:14 PM

I had a 225 do that to me when it idled and I found the boot over the choke was missing and let water in and it caused the choke to stick it's probably not your problem but its an easy thing to check.

**MonkOFox** · 10-16-2013, 02:32 PM

I checked the play in the choke mechanism, it's free. Thanks for the heads up though!

**dougspcs** · 10-16-2013, 02:53 PM

Originally Posted by MonkOFox

I checked the play in the choke mechanism, it's free. Thanks for the heads up though!

No he's talking about the rubber boot on the cable that seals air from getting into the choke plunger..like on the 250SX/ES carb.

But then the ATC200 series carb hasn't got that style of plunger choke..it's old school butterfly choke!

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Carburetor question.