Triumphrat

m2MQP

I'd be temted to recommend anyone with a Serdi head cutter which can be seen here...

http://cylinderheadshop.com/bespoke-...ers/serdi-100/


http://cylinderheadshop.com/serdi-race-shops/

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Ric
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Riding a modern motorcycle because I eventually got tired of remembering what the good old days were really like.

mikeinva

With that many miles you wont be able to just use rings the bores will more then likely be out some what.Theres nothing wrong with the 904 kits though in fact they have better pistons then the stock triumph pistons.Or you can just do the head and maybe you will be lucky.Keep in mind you may have worn oil rings causeing all your troubles.Its kind of a crap shoot with that many miles.

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Why do I feel young on my bike

mikeinva

Yep thats the tool for the job but you still need someone that knows how to use it and understands the cam setup on these bikes.Also they have to have the right cutters for these heads if they have to buy cutters you wont want to pay there bill lol.

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Why do I feel young on my bike

fullplat1

Yep a Serdi is the machine for the job. Can't imagine thata half-decent operator won't have the correct cutter inserts to do the Triumph seats. As for resetting the installed valve height, should be no problem either it won't be the first OHC head they have seen. Is there a standard specification for this, I don't have my manual to hand. If the Serdi operator knows what they are doing they can lightly throat the port entrance to, giving a nice consistant size and shape, all with one set up. To be fair I think the top of the line Kwikway machine can do similar good work, its just that I have plenty of experience with the Serdi and so favour it.
Phil

alfacliff

with the head off, the shims are very easy. I have done valve jobs on my Alfa's and had them done. The first alfa I had blew a head gasket, and I took the head to a ferrari dealer to do the valves while it was off,. while the head is off, check for a ridge around the top of the cylinder, where the rings stop going up. that, and checking for scoreing or scratches in the cylinder, should tell you if the rings are ok, and whether you need to have the culinder bored or not.
cliff

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2006 Bonnie Black
1980 Yamaha xs650 sold 4-30-2011

Bron-Yr-Aur

Conch, an easy, familiar comparison would be a chain/sprocket combo. If you replace a chain and mate it to a worn sprocket, things don't match up and your chain won't even have half the life of one paired with a new sprocket, even though the chain is new. So Mikes point is, you may or may not just have to to minimal work at a small investment, but since, like the chain, the piston, rings, and bore all work together, even a bigger (non-stock) bore kit will most likely be more cost effective. It will last the longest. Yes a stock motor lasts a long time, but probably not with new and old parts mixed in there. And if a motor doesn't smoke, that doesn't necessarily mean there's not serious wear on the rings

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(The artist formerly known as kreemsicleT100)

"Ya can't have 'no' in your heart. Life's a garden. Dig it." - Joe Dirt
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Bron-Yr-Aur Garage

DUCKMAN

At anytime please feel free to comment...but just my 2 cents. I am assuming the bike ran fine and burned NO OIL PRIOR to the valve adjustment. Who did the valve adjustment? If the timing was not set properly the valves would make contact with the piston (interference engine) damaging the valve. Any scars on the piston? Do you have any photos of the damage?

mikeinva

I think there most be a spec allthough I have never seen one.But its easy to measure before removeing the old valves.depth gauge from spring seat to top of stem.Or to make sure its right put the cams in with buckets and shims then take some off the stem untill its right.but there are some not so good machine guys out there that if you give them the head and dont say anything they wont do that for you.The other thing is have the springs set up right allso,some of the young guys out there dont have a clue to setting up spring pressure.On the other alot of auto shops would not know what any of this should be ,thats why its better to have someone that has these motors figured out.

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Why do I feel young on my bike

mikeinva

you cant tell much about how the bore is by looking at it with your eye unless its real bad .It needs to be checked with a dial bore gauge to know what shape its in .

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Why do I feel young on my bike

mikeinva

Not saying it will happen but what can happen to the rings with valves leaking they dont have as much stress on them as they do once you seal the valves up you put more compression on the old rings.If they are near worn out they can blow by.I know alot of these bikes go 100,000 miles but 70,000miles
is alot on a air cooled motor

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Why do I feel young on my bike