Carb Issues.. I have a 2007 Honda CRF100 and when I give it higher RPMs in nutral the bike stops...I know its dirt in the carburetor but I dont know how to take it off. So if you can tell me how that would be great.

I suspect that the throttle cable is out of the end setting from removing and replacing the carbs or a return spring for the cable has broken off and not pulling the throttle back to idle position

Hi Brendan,
The YZ 80 (as you probly know) is a 2 stroke dirt bike which has a Mikuni carburetor (Yamaha part # 1LR-14101-00-00 )
- if it is the stock carburetor -
So there are are a few things to consider when troubleshooting this symptom.
Lets assume your bike is in descent working order. That is to say, your bike has good top end compression, and the power train (from the engine to the rear wheel) is working properly, the chain is properly lubed, wheels and bearings are aligned and free wheeling, the clutch is operable etc..
Anything that could cause unnecessary resistance to the engine and overload it when you release the clutch in 1st gear should be addressed first.
That said; what I believe could be your problem is a dirty carburetor. At Idle,your carberetor is giving your engine the necessary amout of fuel, but when you twist that throttle and pop the clutch, the engine needs more fuel which a dirty carb WILL NOT supply to the engine. If you left the bike to sit over the winter or the fuel had dirt in it, this could be the problem. You could probably use a carb cleaning and tuning. Open the carb up and look for signs of dirt or corrosion causing a blocked main jet, stuck floats and needle valve. Replace corroded parts and clean everything inside. The carburetor on this bike is very sensitive and even the smallest amount of debris will create performance issues. While you're in there, check your reed valves for cracking or bent or missing flaps. And make sure you clean you air filter and use new clean fuel. A fresh spark plug may be in order as well.

Hope this helps. Good luck and let me know how it goes! :)

Dave

Carb diagram:

http://www.bikebandit.com/houseofmotorcycles/1991-honda-xr80r-carburetor/o/m3143sch10211

Manual:

http://www.bikebandit.com/1991-honda-xr80r-motorcycle-repair-manual/n1330?m=3143&f=2

Line from gas tank goes to brass nipple, throttle line goes to top threaded opening, the hole with two bolts alongside it go into the crsnkcase. air line from airbox clamps to the last opening on the carb. The of the openings are vents and overflow.

i got mine on e-bay for $40.00.

sounds like its time to adjust those valves to me 0.003-0.004 on the filler gage or have done at shop.

i have a 83 honda civic wagon that dies at stop lights unless i put it in nutral or park. the carb has been rebuilt what adjustment do i need to make

it the bike has been sitting for a long period of time. the carb. can gum up. pull the carb. off. clean it up really good. insuring you get all the small ports clean. then try it again.
every dirt bike i've had requires a oil wetted air filter. dont forget about that.