need help with 84 xr200r rfvc

Hey all, new to the forms and this is my first post, however i have done alot of reading. To start with, i am not an expert, dont claim to be but i do know my way around an engine. I picked up two 1984 xr200r bikes with the rfvc engines. one of the engines had a valve let go and went through the top of the piston but the bike is in amazing shape and all origional. the other bike is a little rough but the guy who owned it was in the process of rebuilding it and already bought all the cam, timing chain, guides, valves but was only partially assembled. I pulled the engines on both and put the engine in the origional bike. After getting it all back together with alot of help from forums and reaseach I was unable to get the bike to start by kicking it over. I was able to start it by jumpstarting it and on the first start up it was pouring blue smoke and throwing oil out the exhaust. I figured the rings were bad so i tore it down and the rings were good, cylinder and all was in great shape. I changed the rings anyway but i discovered a bad head gasket as well as a leak on one of the head bolts that was the incorrect bolt. after getting it back together i am encountering the same issue, will not start by kick start. it will start by a jump start and this eliminated the blue smoke. Now i am getting a white smoke but bike will not idle and boggy at low rpm. not sure if the timing is exactly perfect, went by info i found, lobes on cam down, line across the cam sprocket and the T is lined up as close as possible, as well i am unsure of any adjustments that can be made on the twin carbs. any help would be greatly appriciated. also, on a side note, i took the carbs off again and when i kick it over with no carbs the engine pushes air out the port where the carbs bolt on. this is why i decided to ask for help. I was under the impression it should be a suction when kicked over.

just an update, i took the carbs off again, and when i place my hand over the intake port where each carb mounts on i only get suction out of one of the intakes. the same intake also blows back compression into that carb. the other port doesnt seem to have any suction or compression when bike is kicked over.

The 200 RFVC engine is based on the 84 XR250R RFVC engine so IMO the best tech info would be on the 250 Forum. 

This forum is all about the 80-200 two valve engines so any advice would be general in nature.


Your symptoms sound  cam timing and valve clearance related. 


Compression release set correctly?

Where did you manage to get your piston rings from? I have the same bike

I've got the exact same bike, legendary machine once theyre all sorted out. I remember I had  a few problems with starting it, (would only run start) a few hours of cleaning and adjusting float levels in the carbs soon fixed it and it now runs like a dream.


However, it appears that your problem is most likely a bit more than just some dirty carbs, like chuck said, best help would be on the 250 Forum.

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