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YZ285 Jetting Woes

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OK. This is what im down to. Every time i take it out, even without messing with the jetting, it has different symptoms. There are no air leaks. IM so confused.

Ive got...

N3CJ at clip 2

175 main

48 pilot

air screw... i dont remember

Running 91 pump with castor 927 at 32:1 (cant afford race gas, probably should be running it) ran great when i first got it on pump, so this probably isnt the problem.

First things first... is castor 927 a good oil?

2nd off... here the thing...

When its WFO, it runs fine... well it runs OK. I know im missing power there... but i could give a crap atm because if you try and give it any throttle below WFO, its horrible.

I can barely ride it, when i dont give it wfo, it like herky jerkys forward. Its giving me arm pump out the ass. I can barely ride it... and then when you start to crack it open, it will just hit the powerband SOMETIMES and take off. HARD TO RIDE. The power is not what it once was. Theres no mid hit, and... well ok theres no anything but top end. Its all just lack-luster. Its got no more 2 stroke snap like it did.

I asked my buddy to ride it, and i hopped on his 500 4 stroke... he rode in front of me.... i noticed my bike was smoking ALOT. There spooge on the silencer. So okk... gotta be rich. He stepped off it 15 minutes later and said "SCREW THAT" cause it was so hard to ride. He was completely wasted after only 15 minutes.

Im afraid to touch it. Every time i do, it just gets worse. The plug... its confusing as hell. Some parts it dark, some tan, some lighter tan, some really dark brown... down inside the plug it looks really dark.

Some spots it seems lean... some spots it seems rich... ***!? when its cold, and its on the stand, you try to crack it open, it bogs. When you get going, its herky jerky. It has issues starting too. It will only start without the choke, never with. It will not idle either.

So heres my options... Buy a JD jetting kit for 75 bucks and HOPE i can get it dialed in with LOTS of frustration... or... i can have screwie lewies jet it for 100 bucks... What would you do?

Any sugggestions? Im at my wits end here.

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I can say Castor 927 Is great stuff !! ,As for the Plug , Eddie the expert says that with all the additives and stuff in gasoline its hard to tell by the plug , but you still can get a reading . I Would buy the kit and do it myself , but i hate the frustration myself unless screwie lewies knows what hes doing and he can get the job done. Then go with him. Well hope this helps .

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sounds like a crank seal or case seal.if you noticed lots of smoke(more so than normal) it could be sucking in tranny oil.

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Not a drop of oil missing. No oil in the clutch side...

EDIT* I meant flywheel side

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Hey man, I also have a YZ285. It seems like you are too rich down low. I run 32:1 and had the same problem with the 48 pilot so I dropped it to 45, turned the air screw all the way in, then two full turns out and it rips like no other. As for your plugs, the 175 main is what I run which is good for me and probably good for you giving you a tan colored plug, its when you switch from riding in high rpm for a prolonged period then back to the very rich bottom that would most likely give you a multicolored reading. Dont give up on the yz285 b/c once you get her where you want she will f***ing fly.

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sounds to me like you are too rich everywhere but the top as well. Lean the mid by raising the clip on the needle. If that helps, but doesn't clear it up, it's time to start changing the pilot, and the needle. Also make sure you are using a new plug. The plug you are using now, may be misfiring under load. I just had a RM250 here in which 3 different people tried fixing pretty much the same condition you described. Another brand new plug fixed it! Just because you have a new plug, doesn't mean it's any good.

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