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2013 yz85 carb adjustment

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Bought a new 2013 yamaha yz85.

Running yamalube 32:1 mix

BR10EG plugs

The bike runs good but it is burning out a plug every tank of fuel. The porcelain is burning out around center electrode both electrodes are black.

I tried to adjust air/fuel mixture if I rev engine slightly and turn screw out or in there is no change until I turn screw all the way in where it quits.

Normally on a four stroke I turn air/fuel screw out about 2 1/2 turns warm up bike then give it some throttle while turning screw in until I hear it rev then flaten out than back out 1/4 turn. This has always worked for me.

Maybe I am adjusting the yz incorrect but it seems to be to rich even if I turn the screw all the way out with an almost black smoke from exhaust. The air filter had way to much oil on it I tried cleaning it with hot soapy water thinking this could have been causing a rich fuel mix but it's still the same.

Any suggestions?

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Can you be more specific? What do you mean " the porcelain is burning out around the center electrode"? Can you post a picture?

So it's not your run of the mill fouling of the plug?

You're talking about how you adjust your 4 strokes and the YZ is a 2 stroke. You understand, right, that a 2 strokes pilot screw meters air, not fuel like a 4 stroke. So its operation is backwards to what you're used to with the 4 strokes screw.

On the YZ, in on the screw is richer, out is leaner.

What octane fuel are you running? Still stock jetting I assume. Check the owners manual for jetting recommendations for your elevation and weather compared to what it came with stock.

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Yes I know the difference between two and four stroke. I was explaining how I make my adjustments on a four stroke bike so if it's different on a two stroke maybe someone can tell me the correct way.

I'm running premium fuel 93 octane.

The porcelain in the plug around the center electrode is cracked or ruptured. If I pull the plug and lay it on a ground you can see it sparking down inside the plug.

Sorry not good at proper grammar or spelling.

I only have internet on my iphone and have not figured out how to upload a photo.

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Is that spark plug the stock part number? The stock heat range?

Cracking the porcelain is definitely not right. Things that could cause that, things like predetonation, wrong plug for the application, plug too long and contacting the piston.

A lot of bikes stock jetting is too lean. Giving that you're not seeing any change in the air screw til almost closed, I would increase your pilot jet size to start with.

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