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View Full Version : 84 250R - to keep the bigbore or not...



cduemig
02-28-2011, 12:35 AM
I just picked up an 84 250R with a title for a great price. It's not far off from being a running bike but it blew the head gasket.

The guy said it had a 330 big bore. He had the entire engine rebuilt just over a year ago. He said it ran unbelievably until it started bogging and then he couldn't get it started. It's showing 50 psi compression right now and you can hear air escaping the through the gasket. He said he didn't think the jetting was right on the mikuni carb and it ran hot and blew the gasket. I could just replace the head gasket and rejet, but I'm a little leary about a 330 big bore on an aircooled R.

I'm going to pull the top end apart tomorrow to see what's really in there, but looking for opinions. I can get a sleeve and top end kit and put her back to stock or try out a new gasket first...

I do mostly trail riding, but I still have my 350x and wanting to give this one a try out at the dunes near the coast.

cr480r
02-28-2011, 05:45 AM
doubtful your gonna sleeve a big-bore cylinder back to stock... so fix the head gasket(will need a big-bore gasket), re-jet the carb and give it a shot.. if it then fails, then sell it and buy a whole new topend..