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Discussion Starter #1
Hey, I've noticed that every spark plug on my bike has a black, oily substance on them enough to leave long black marks on my hand and drip off the plugs. The bike struggles to fire when starting (cranks forever to the point where I need a jump it with my car to eventually start it), and I have no clue if this is related.

Is it oil? or gas from being super-rich?

Thanks.
 

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If it’s hard to start the plugs might just be fouled with fuel. Longer you try unsuccessfully to start it the more unburnt fuel gets accumulated, because of the carbon in a used motor it will often look black like oil. You can usually smell the fuel on them.
Normally there isn’t enough oil in the chamber to be that unless you have bad rings. If you can get the bike running and it’s making power I doubt it’s oil.

What kind of battery do you have? Is it an AGM?

Are you using the choke?
 

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Discussion Starter #3
If it’s hard to start the plugs might just be fouled with fuel. Longer you try unsuccessfully to start it the more unburnt fuel gets accumulated, because of the carbon in a used motor it will often look black like oil. You can usually smell the fuel on them.
Normally there isn’t enough oil in the chamber to be that unless you have bad rings. If you can get the bike running and it’s making power I doubt it’s oil.

What kind of battery do you have? Is it an AGM?

Are you using the choke?
Choke is on full, and I think it's AGM. It's about 25 degrees when I try and start it so I don't expect it to start easily, but 3 minutes on the starter seems a little steep.
 

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Discussion Starter #5 (Edited)
If its 25 and you’re not going to ride, why are you starting your bike? You’re just wearing the battery down and causing extra wear on the engine.
It's my winter project, I am fixing it from a non-running state.

And now that you mention it, I'm positive it's fuel fouling the plugs because with the plugs out cranking it over with the choke on produces a lot of fuel to shoot out the spark plug hole. I was worried oil was leaking in from somewhere.
 

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Discussion Starter #7
Well if you’re not working on it every day, and it’s below freezing, I’d bring the battery inside. Do you have a battery tender? You can just reinstall it when you want to work on the bike. Might make starting easier ;)
yeah, I hook it up to a battery tender when I'm not working on it. I also have a ninja 500 which has the same battery, so that helps.

I found that the plastic fuel nipple on the carb was broken and that the float bowl gasket wasn't working. I hope that fixing these will solve my issue, as the rear cylinder is running extremely rich. (putting my hand behind the exhaust covers it in unburnt gas). I'll also probably take the pucks out and reset the mixture screws, and then sync the carbs.
 
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