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kx85 bogs no matter what after rebuild

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after a rebuild low end top end jug i put the bike back togther cleaned carb...well the bike will idle all day long and rev a bit real good then when i try to accel it will bog and die on me...then i let it sit and the overflow spills out gas...any idea what it is? float? jetting?

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Most likely the float is sticking... sounds like your getting too much fuel getting into the float bowl. Go in and make sure it moves freely and measure to make sure float height is set to correct specs.

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the specs are ever so slightly off....i tried adjusting the screw on the side but nothing sounded different and it still ran the same

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if your float is out of adjustment you can not seat the carb right !!!! set the float hight and then start the adjustments then if it runs right read the plug a new one after a few runs also check the plunger needle it could be worn , also check the c clip on the needle they can come off ??

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you can't adjust the float height through turning a screw on the outside, the screw you're messing with is your pilot air/fuel mixture screw.

You have to open the carb up and bend the tab on the float bowl ever so slightly one way or the other so it closes the needle valve at the appropriate fuel level in the bowl- you're either getting too high or too low of a fuel level in the carb,

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i did bend it and it is a lil under specs so i guess it isnt enough to keep it from overfilling...will have to take it apart again thanks

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WHOA, WHOA, WHOA!!!

Who did the build and did you check the alignment on the KIPS shaft?

If you're not sure what I'm talking about, GO HERE

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my dads friend that specializes in 2 strokes...he races 2 stroke dirtbikes.. i trust him and i know the kips you speak of...i doubt its that because i have been able to ride it a lil bit before it starts bogging and you can definately tell when the valve opens inhexhaust caus it pulls real hard..big hit ya know..

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Yes, the KIPS alignment will do that. I'm not doubting anyones ability to properly build an engine, but this area is often unkonwn and overlooked. Hell, I spent 3 years working on my sons 100 and have caught myself not paying attention to the alignment. It's a simple mistake.

Also. the only true way to set the float is to have the proper float level gauge. It's @ $45 through Kawi.

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ok well how can i tell if the kips is out of alignement...when i take off the cover before the build and after the build it moved the same way

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Look at my first post, click on the link GO here, and I made it too easy. It's pictures. About the 14th pic or so shows the KIPS shaft and how it gets aligned. It will be off slightly when hooked up. BUt thats the aligning mark.

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I have an 06' kx 100 the is doing pretty much what sounds like the same thing. It revs fine right up until about the midrange then will not rev any further, and then it will cough and then die. It's also very hard to start. The topend has 1 hr on it. Gas is fresh,I've had 2 seperate carbs on it, a new coil. I'm stumped here. If you find out what the problem with yours is post back.

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Did you look at my thread in FAQ & follow the directions I gave Sloaty? How did it run prior to the rebuild? Did you do any mods/change anything? There's alot of variables but we have to eliminate the obvious and most common mistakes first. Also, while you're at it, check the coolant level. After a rebuild, it can be common for the head to warped and you're losing compression from a head gasket. It happens.

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Yes, I saw the the thread that you posted. The mark on mine(my nephews) is slightly offset to the left by 1/8th". The bike ran fine after the rebuild, he raced the Unadilla GNCC and finished inside the top 20 OA. He warped the head earlier in the year a mini national HS in New York. I had the head Milled flat again, .010 was needed to straighted the head out. It's straight now an the coolant level is good, I checked. I checked the crank bearings, tried moving the flywheel side to side, and they are fine. The rod bearings were good when I put the piston in. Have you heard of ingition problems with these bikes? I even changed the reeds. Nothing I do seems to make the bike run better. It just runs the same. It's really frustrating.

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looked at the bike pulled the kips cover and the e clip had fallen off and the kips was not even connected at all from where the clip fell off i inspected the alignment and all is good....so i bent the e clip to make it fit better and not fall off....i will start tomorrow and see if all is fixed

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i know the carb is still a lil off but atleast it shouldnt bog like it was

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Good deal. Should be ok now

rtv - I've never had or had anyone I know with an 85 or 100 having any ignition issues. But...The worst case scenario is a broken power valve. This is common in the 100's. Or possibly the small allen head bolt in the PV came out and isn't operating the PV properly. A dab of med strength loctite is used on that small bolt. Otherwise is vibrates loose. There's a few things it could be, Governor PV, possibly plating in cylinder allow low comp and blowby.

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I'll pull the power valve apart and have a look. I'll post back if it's anything in there or if I do figure the problem out. Thanks for the help.

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