hard to start carburetor - Wrist Twisters
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post #1 of 6 Old 03-15-2014, 07:27 PM Thread Starter
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hard to start carburetor

I currently have a kawasaki vulcan 750 2002. It still has the same problem that it had when I bought it. It is hard to start. And when it does start, the idle is not constant. I have spark, I have fuel and air. Vacuum line seems to be good too. I can feel suction. Not a strong pull, but still suction regardless.

The thing that is bothering me is my petcock. It has a vacuum line leading to it. I understand that in my petcock, there is a plunger that is actuated when there is vacuum, allowing fuel to pass through. But if there isn't any vacuum, then no fuel passes. Could amount of vacuum I have effect why it is hard to start?

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post #2 of 6 Old 03-15-2014, 09:47 PM
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Sounds like a plugged jet somewhere in your carb. Probably the pilot jet? I believe this is the low speed jet which causes idle and starting issues.

Some more knowledgeable than I will pipe in.

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post #3 of 6 Old 03-15-2014, 11:13 PM
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Yes, it might have tiny pilot jets that clog easily. Our SV650 was a hard-starter until I changed the jets from 15s to 17.5s. Beyond being hard to start, sometimes one or both of the old pilots would get clogged and it would run like crap.

I don't think it's your vacuum petcock. That would cause a delay in starting if you hadn't run it in a while, but the inconsistent idle points to a carb issue from my experience. I'm not familiar with that bike, but I'm guessing it has tiny pilots like ours did. Sometimes running an additive can help get things cleaned out and running better, but if anything is completely clogged, it would have to be taken apart and cleaned out.

Maybe you have already, but it might help to do some searching on your symptoms and that specific model. You might pull something up, and even find some steps to help correct it.

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post #4 of 6 Old 03-16-2014, 05:45 PM
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This points to pilot jets and/or idle adjustment screws.

Make sure your bike is warmed up and then adjust the idle for the appropriate rpm range. People typically idle down for a more po-ta-toe sound.

If you still have issues, time to run some seafoam through and if that doesn't help, you have a physical clog in your pilot circuit that requires the carb to be disassembled and cleaned. This is advisable anyways as it is usually recommended to replace the main jets even if your air intake and exhaust are stock.

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post #5 of 6 Old 03-16-2014, 05:50 PM Thread Starter
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I appreciate your help. I took my carb off and cleaned the whole thing and replaced the jets and float. It seems to be working just fine now. I appreciate everyone's input. You guys are great.

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post #6 of 6 Old 03-16-2014, 05:51 PM Thread Starter
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