82 XR 250R smoking like a chimney!!!

I just finished tearing apart my old XR and I cleaned up everything, like new and I had to put in a new camshaft and rocker arms. Actually, I had them refilled or hard face welded, or whatever that is, only because the parts were not available in the country that I am living in. Anyway, the inside and outside of the motor and the rest of the bike looks perfect, now, spotless, all painted and I just finally put it all back together, again. This old tank has sat in the garage for over 4 years and I finally decided to fix it up. I cranked it up, today (started on the 3rd kick) and everything is running smooth, now, except it is smoking extremely bad and when I put my hand over the end of the muffler it sprays out oil. I am sure that I need new rings and/or possibly valve seals, as well. I would have replaced them when I had the engine all apart, but, as I said, here in Costa Rica, it is very hard to find parts, especially for older motorcycles. What do all you experts out there think I should do? Fortunately, I can have a friend bring me these parts from the U.S. when he visits me in a couple of weeks. I know that the cylinder and piston and everything else is fine. I cleaned up the rings, but, maybe they were still too worn out to work, again and I do not have a way to measure the gaps. I did not do a valve job, but, I will do that now. I adjusted the valves and had a motorcycle mechanic friend double check them, for me. I also, put in fresh, clean, Penzoil 20w50, synthetic, because that is the best I could find in the little shop here in my area. Many say synthetic and many say regular, so I am not sure about my choice with oil. Any suggestings on fixing this smoking problem? The smoke is white or grey and it is not blue or black.

It sounds like your only bet is to replace the rings. My XR400 smoked like that, and it was the oil control ring. The valve guides will cuase oil to burn, but typically the valves expand into spec and stop this oil from seeping. That burn is very minor, and it burns off after everything is warm.

I would have for sure replaced the rings. I dont know much about international shipping, but maybe you can contact service honda and see if they could help.

Get rid of the synthetic oil!! Its fine for tight engines, but in worn engines, the longer molecular chains actually make leaks worse! Going to fossil oil should reduce the smoking, maybe not all, but you should see a big difference. Post your results!


valve guide seals you might as well replace while you are in there. i agree with iceslice, if it were only seals you would see smoke at start up and immediately after and then the smoke would dissipate. it sounds like rings but i would also check your head and cylinder top deck to make sure they are not warped. i have an xr100 that actually had the cylinder top deck warped. a machine shop can check the flatness or you can do it on a granite surface plate or other extremely flat surface. use a feeler gage and run the gage under the head or cylinder as it sits flat on the surface. .001 inch to .005 inch shouldn't be a problem. more than that could cause oil to pass into the combustion chamber via the cam chain channel.

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