[Castle81]

I would say your cheapest option is to get a low milage used motor. As much damage as there is, a refurb on that motor will get costly quick. You'd have to have the whole block & head machined, resurfaced, and align honed. Not to mention hard parts like bearings, crank, cams, ect are probably toast too. Then there's the fun part of tracking down oversized bearings & possibly pistons. Unless you know how to mic and blueprint a motor, you may be in way too deep.

This is an almost absurd amout of wear. It's possible that a single failure somewhere internally caused all this, but neglect and abuse are far more likely. Either the maintenance hasn't been done...ever...or the someone flogged the holy hell outta it. If the cusomer has had this bike a while, be careful. They'll be back again soin, and be blaming you for the bike not holding up. I wouldn't encourage someone like that to swap in a larger motor, either. They need to dial back how hard they push this bike, or get a proper super sport to kill themselves on.

 

[Castle81]

Sorry if we seem cold. I'll try and rephrase your post in car-terms. Maybe you'll understand the reaction you got that way.

"My friend just brought me a 1.6l civic. It has a header, exhaust, and cold air intake. The rings are toast, the bearings are shot, and the valvetrain is gone too. He read somewhere that the 3.0 drivetrain from the NSX will fit in there. Is this possible? How much work would be involved?"

Ideally, you would advise your friend to not thrash an economy car, and if he insists on going fast get something that was intended to do so. Swapping engines in bikes can be risky business. Weight balance is far more critical on a bike than on a car. Creating some frankenstein monster that was never meant to be will likely result in an unstable pos, and is a good way to get someone hurt or killed.