660 raptor running way too rich

my 660 raptor has bit of black smoke on acceleration. starts good runs ok just lots of black smoke any suggestions?  thanks  freight

Tune the carbs?

I replaced all the jets made sure the needles were in the right slots didn't move the fuel screws.everything has been cleaned the floats and needles look fine so I am kinda at a loss unless the fuel is contaminated. thanks for your input   freight

It sounds to me like you have an oil leak...The Raptor 660 is a 5 valve, overhead-cam 4 stroke... no oil in the fuel so the carburetor is not going to have anything to do with it... Do you have water in your oil? if yes, then its probably your head gasket, but it is more likely your piston rings or valve-guide seals... does it use alot of oil? My brother had a '04 raptor 660 a few years back that never burned or leaked any oil and it was abused regularly...

Seems like its running very rich that is why it produces black smoke. If its burning oil its should produce bluish white smoke.

I know the carbs are good. could valves out of adjustment be the culprit? it doesn't run bad just smokes.could a intake boot leaking cause the smoke? thanks in advance freight

You can check the valve clearance just make sure to use a filler gauge to be precise in the gap. You can have a compression test just get an idea about your engines health.

I am going to check the compression when I get a chance. the unit has low hours so I am hoping its a valve adj issue. but when checking tonite I found the airfilter assembly is not even attached. so it might have been dusted. got to get my leak down tester back. and that will decide the next move. thanks in advance  freight

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