2004 YAMAHA YFZ 450 ALL STOCK, HEADLIGHTS STOPPED WORKING, BREAKING UP AT HIGH RPM BUT STRONG THROUGH 3/4 THROTLE, REPLACED STATOR, RECTIFIER, CHECKED ALL JETS WERE CLEAR, LIGHTS ARE BACK, STILL BAD AT HIGH RPM AND OVERHEATS NOW, CLIP WAS ON 3, MOVED IT TO 4, USED TO STOP POPPING AT 4 TURNS OUT, NOW NOT AT ALL, SHOULD I TRY THE CLIP ON 2? ANY THOUGHTS?
Question edited for full 'year make model (what it is).
Question moved from motorcycles to make model category.
Please don't type in all CAPS, it is considered SHOUTING and is harder to read.
'clips' and 'turns' it took me a while to realise you were talking about the carburetor and you were playing with the mixture screw and needle position! 4 turns out is a lot different to the factory setting which is 1 1/2 turns out.
If it is overheating it is running too lean. As you changed the stator, also consider the ignition timing. Popping can also be caused by the ignition failing under load, coil, lead and spark plug.
Carburetor and tuning.
https://www.google.com/search?q=2004+yamaha+yfz+450+carburetor+adjustment
This carb has a LOT of jets!
https://www.amazon.ca/Carburetor-Rebuild-Yamaha-YFZ450-2004-2009/dp/B07JNYP667
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THANK YOU, SHOULD THE CLIP REMAIN IN THE FACTORY 4TH POSITION OR TO 2ND OR 5TH, NOT SURE WHICH WAY TO GO, 3RD ACTUALLY DID A BIT BETTER SO 2 MAYBE?
ALSO I AM VERY NEW TO THIS, HOW DO I MAKE IT RUN RICHER?
Please turn off the CAPS LOCK! Better to type in all lower case.
All the settings need to be in factory position, then you make small changes based on performance. Our dearly departed bike expert Gregg Mahin used to post what the idle mixture jet, the needle, main jet and the slide did in respect of fuel flow and throttle position. For instance at wide open throttle only the slide is involved in metering air and fuel via the main jet, nothing else, not even the needle. to make it run richer, you need more fuel adding to the air. Another thing to consider is the float Chamber and the float needle jet in the bowl of the carb. There are ways to set the level. It is tedious, but you have to have the level so that at Wide Open Throttle (WOT) that bowl isn't drained of fuel. Watch the videos in the link I posted, buy the service manual. Here is a free copy. We were all new to it at one time, I started in 1968. Read as much information as you can and learn, then 'do'.
Free Service Manual
https://quads.ddns.net/service-manuals/y...
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thank you very much i'll post my progress
Great, keep us updated.
ok so i didn't have the tools for the ignition timing, but the friend i called did have a 175 main and a 48 pilot that he said worked nice on one he had, now i'm over 5 turns out and worse popping, box cover off, clip on 5, i'll wait for the timing tools but shouldn't these jets have helped some?,i'm not sure if i should go back to stock and time it or leave these in, i know i should have tried timing first but everyone i know kept saying it's too lean, now it's worse
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