Engine gurus needed

[Guest]

Helping a friend with his 79 1000E and cams have the clearance but wont turn when even tightened down just firm let alone to specs. I know cam caps are meant to be never switched but i think someone has. Bike was brought engine not running but owner said just had top end rebuilt. Needs 4 threads fixed and there are high spots every where in the journals. Can you still line bore the head/cam caps or should i just look for a good head off a CV carb model? Not too keen spending hrs trying to rub down the high spots with emery.FYI, person who built this needs to be shot. Its one of those bikes LOL Thanks

[GregT]

I'm assuming the caps are in the right places by numbers ? Check the cams for straight before anything else....

I will admit to having align honed a couple of Yamaha FZ heads - the caps are often badly marked on them and people get them mixed up.
Quick and dirty, piece of steel tube just smaller than the cam journal size,long enough to reach one side while turning from outside the other, slot in one end to accept wet and dry paper. Caps obviously tightened down. Slow speed in a drill or on a lathe bed. Do the absolute minimum to just achieve free turning. Clean thoroughly.

[Nessism]

Jay from APE says that cutting the head (gasket surface) to remove warp is a bad idea because while you may fix that issue, the cam bores will be off. He advocates straighten the head by bending before any serious resurfacing is done.

If the head in question has been resurfaced that may tell the story. It should be relatively easy to check for warpage with the head flat on a surface table and using a height gauge to check the cam bores.

[rudeman]

I'd get another head and recycle the old one; dump it in the curbside recycling bin as scrap aluminum.

[Rensdw]

what about having the camshafts welded and then do a professional rebore? anybody done that?

[rudeman]

If the head had warped, what assurance do you have that everything still lines up properly? You have to check that the CC lines up with the bore centers, valve stem bore alignment will be off and then there's the alignment of all the bolt holes with the valve/cam cover and with the cylinder. Those will all be off to a certain degree.

[hampshirehog]

I would try and find out if it was just one cam cap causing the bother and if it is you can decide what you want to do with the offending article.

[sharpy]

Dont think the head is warp. Just they used caps off another head. But both cams dont look great on the journal either. Just trying to fix what someone who shoulddnt touch bikes made up i think. thanks for the suggestions

[sharpy]

All sorted. mate went and paid for a complete head with everything and cams for 100 bucks. High mileage but have to see what the valve guides are like. Hasnt been butchered as far as i can see so far .