1983 models had an internal oil passage to feed the head, wet sump, dual carbs. Dual carbs was in theory OK and gave great mileage if you didn't crank the throttle wide open but I think history sees them as an overcomplication with little benefit over a single carb. There had been a few cases of stuffed heads in 83's if the owners ignored basic maintenance (good oil and filter regularly). Summary OK if maintained potential nightmare if not.  Drum brake front. 339cc

1984 Honda added an external oil line (chromed) and stood out like crazy but this thin oil line greatly improved oil flow to the head and therefore reliability especially for the lazy. I owned an 84 and did about 30,000kms before a rebuild (75% road 25% dirt). Still had dual carbs on the 84 model.  Disc brake front.  339cc

1985 came along and honda went to single carb (35mm) and a dry sump and the 85 version was written up as vastly improved and I would have to agree.  It also came out with honda's enduro meter rather than a speedo.  Simple functional reliable but are getting harder to find parts for.  Disc brake front.  Stroke increased by 3.5mm to give a displacement of  353cc

I ride with mates that have XR400 (stock) and modified XR280 (Ballards) and these are great for a broad range of ability. Another bike you may consider is the TT 350 a good solid performer if money wont stretch to a wr400 or 450.
Regards.

I have read that an 88 CR 250 front end should bolt straight in. 

3rd gear failures are apparently also common and can cause significant damage when they occur.

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