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Discussion Starter · #1 ·
I was going to wait until winter to really get in to my '71 CL450 mechanically, but it looks like I'm starting now instead. The other day I took off the exhaust and there was thick, black, gritty liquid goop inside the RH cyl exhaust port. I'm not sure exactally what caused it but whatever it is I need to at least tear down the top end and find out.
I have the engine out and on the bench. The bike has 12,500mi on it and has sat for the last 25 years or so. What is the life expectancy for valve guides/seals on these bikes? I'm sure the main factor is use of the bike, but do they generally need replacing sooner rather than later? What else do I need to look for? I don't have the head apart yet, but looking down the ports I can see that the ex valves are very carboned up.
I don't think I would undertake such a project without this forum and the amazing annotated manual on CD that Bill (tbpmusic) made. Seeing regular guys doing good work on limited budgets is an insperation.
 

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Discussion Starter · #2 ·
Glad I went ahead and took the plunge. It wouldn't have done me any good to try to get the bike running as it was. I pulled the head and cylinders today and found:
[attachment=0:1174a6qb]valves 2.JPG[/attachment:1174a6qb][attachment=1:1174a6qb]valves 1.JPG[/attachment:1174a6qb][attachment=2:1174a6qb]pistons 5.JPG[/attachment:1174a6qb][attachment=3:1174a6qb]pistons 4.JPG[/attachment:1174a6qb]
The top ring on the RH piston is stuck. The bores look ok but will need to be mic'd to be sure. The valves look terrible. I will at least be needing some head work. Keeping in mind my (very) limited budget, would it make sense to try to clean up the valves and reuse them or am I going to need to get the seats re-cut and get new valves? There is a local independant shop that advertises machining services, but they specialize in much later-model bikes.
 

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aamj50 said:
Keeping in mind my (very) limited budget, would it make sense to try to clean up the valves and reuse them or am I going to need to get the seats re-cut and get new valves? There is a local independant shop that advertises machining services, but they specialize in much later-model bikes.
Allow the machinist to make the call, both for pistons/jugs, and the valve work..........
 

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Discussion Starter · #5 ·
Mikevan10 said:
What do you find so "terrible" looking about the valves?
For one, they're rusty. Also there is very heavy carbon build up on the other side, which I didn't get a picture of. All the engines I've had apart up to this point have been more modern designs, maybe I just didn't know what to expect. On top of the general cruddiness of the combustion chambers I was suprised how tired all the parts look overall. Pistons, jugs, etc all look more worn out after 12k miles.
 

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"I was suprised how tired all the parts look overall. Pistons, jugs, etc all look more worn out after 12k miles."

Interesting. I wonder what would be considered an "average" mileage before a top end freshening would be appropriate for these machines. I know , there are so many variables, but would, for example, 12k miles be a reasonable lifetime?

Just wondering....

Good luck with your rebuild Amm. Keep us posted!

Mike V.
 
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