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Rebuild or replace head?

Old 08-22-2007, 04:22 PM
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Rebuild or replace head?

CCT failure in the front cylinder = pooched valves. Cams, etc are fine. Should I rebuild this head or buy a known good used head? I have located a set of heads for about the same as rebuilding my current head.

If rebuilding is the route I should take, does anyone have a set of valves they want to part with? Do the guides usually end up damaged in this apparently common scenario?

If I buy the pair of heads I'd be selling the rear cheap as I don't need it. Anyone interested?

Thanx in advance for your responses...
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Old 08-22-2007, 05:19 PM
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Originally Posted by driven View Post
CCT failure in the front cylinder = pooched valves. Cams, etc are fine. Should I rebuild this head or buy a known good used head? I have located a set of heads for about the same as rebuilding my current head.

If rebuilding is the route I should take, does anyone have a set of valves they want to part with? Do the guides usually end up damaged in this apparently common scenario?

If I buy the pair of heads I'd be selling the rear cheap as I don't need it. Anyone interested?

Thanx in advance for your responses...
I question whether "known good used" exists. Maybe I'm just fickle with all this used parts stuff but the stuff on Ebay is dangerous - mostly junk or surely part junk. If one of the cammers from here at the forum had head parts left over from a build, then I think you would be ok. I think the entire assembly should be refreshed at rebuild. That said, I'm not sure I wouldn't do the same for the rear as well. You're going to be in there anyway so might as well make a clean sweep!
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Old 08-22-2007, 07:57 PM
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Can't rebuild both heads, bike bank is too depleted! So, is this normally a valve change or will the guides need replacing?
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Old 08-22-2007, 08:21 PM
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I'll be replacing the heads on my VTR shortly ("new" heads are currently being ported by dealer, will be mated to Yoshi Stage 1 cams) so I'll be looking at getting rid of the old ones. If you can wait a bit and are interested let me know.

cheers
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Old 08-22-2007, 08:44 PM
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PMd you...
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Old 08-22-2007, 08:50 PM
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Oops - your box is full!

How soon is 'shortly'? I've located a set for a reasonable price - what will you be looking to get for yours? Temps are dropping here in Maine so time IS a factor!

Thanx!
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Old 08-22-2007, 09:37 PM
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Hi again,

mailbox is now empty IN terms of timelines, I would love to get it done within two weeks at most but as I'm getting a good deal from my dealer, well, I am in no position to turn the screws on them too much.

PM me and we can discuss this further.

cheers
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Old 08-22-2007, 10:34 PM
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You can usually get away without replacing valve guides but it depends on how well they faired. How are the valve seats? If you need to cut the seats the job turns into a clearance nightmare. I would recommend replacing the head. You should be able to find a good replacement. Its pretty obvious if the replacement head is damaged. Just look for unseated valves, cam bearing surface damage, and cracks. Remember the two heads are different. The cam chain tensioner mounts are reversed.
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Old 08-23-2007, 04:54 AM
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Thanx SD, yes, I have noted the difference between front and rear heads. There are plenty of rear heads available but front heads are rare. I'm assuming these go bye bye far more often.

mikstr, I can't wait 2 weeks. Sorry man but thanx for the offer.

I'm taking the head to a reputable machinist today to get his opinion. What blows is that all 4 valves will cost more than a complete spare head (minus cams). Which brings up another issue - I'm not crazy about putting my cams in a different head. I can always plastigage them to check clearances but if they're out, then what? As I stated before, I can buy a set of heads complete with cams but I only need the front and really don't want the extra expense of buying both or the hassle of trying to sell the rear one.

I'll know more after I speak to my machinist.
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Old 08-24-2007, 05:22 AM
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I have a spare front head if you want it. Let me know. PM me.
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Old 08-24-2007, 05:38 AM
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AWWW MAN! I just ordered a complete set (front and rear) yesterday. Complete w/cams, valves, covers, etc. Thanx anyway... Ordering my APE tensioners today. Should be back up and running next weekend!
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Old 08-24-2007, 06:08 AM
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Patience, Grasshopper...there are always solutions around the corner...
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