CBX250RS-E Engine Rebuild 11/03/2012

After stewing over it for a bit and looking at the prices of having a head repaired (!) I did some looking on t'interweb and it appears that cracks between the plug and valves are something of a feature of RFVC engines, particularly the 250s and particularly the earlier dual carb models as they have less space between the plug and valves than later variations. In fact people were recommending getting another head with cracks that are nowhere near as bad as mine, like this - http://www.thumpertalk.com/topic/681904-84-xl-600/.Mine is also the only example I can find with a crack on the inlet side, basically it's scrap and then some. So I begrudgingly started stripping down engine number 2 expecting to find it will be just the same, but no! Something actually worked out well!

That'll do nicely!

I'm not sure how it has survived so well, I ran it with smaller jets and an air leak in the airbox for a thousand miles and I wasn't kind to it, and I have a suspicion it has been raced. But it doesn't matter.. Onwards!