I just rebuild my wr200 and have been having trouble.
I completed the break-in process and am now running 52:1 with Golden Spectro synthetic oil(the container says to run this mixture) and 92 octane gas(highest they sell here). Now when I first start riding it runs perfect, absolutely awesome. I ride for about 2 minutes to a long stretch of road(nobody lives on it) and go full throttle for no more than 30 seconds in 6th gear(it flies, very fast). Then I stop at the end of the road and turn on to another road and make a big loop back to my house(probably about 5 minutes). It seems as soon as I stop at the end of the long road it stops running good. After about 1 minute it really runs bad. It will have little power and make a sound sort of like a card stuck in the wheels when I try to accelerate. It even quickly lost power and stopped, I got off and checked everything then started it and it worked(still ran bad but still started). If i let the bike idle while in gear(like when going down hill or slowing down) the engine will give pulses if power everything couple seconds.
The only mods are boyesen power reeds, and a uni air filter. I am running 1 1/2 turns out on the pilot screw(says to do this in manual). I checked the plug and it is a light charcoal color and very dry. Also if I leave it alone for about 10 minutes then take it out it will repeat this whoel cycle(point is it would run perfect at first)
Please help!