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Discussion Starter #1
Hello,

I just recently picked up a 1971 cl450 and it definitely appears to be a project bike. all the parts seem to be there as I acquired it from my friend and I was going to get ready to do a tune up. Before doing anything beyond getting a new battery I did a compression test.

BAD results :| Left Side: 120 Right Side: 0

so its looking like a top end rebuild. I don't know if this is something that I can do or something that you guys would recommend. If you have any advice, comments or suggestions please let me know.
 

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Discussion Starter #2
As a added note here: About 5 years ago my friend had the top end rebuilt; new pistons and new springs ect... I find it hard to believe that the problem I am having is solely gasket related though.
 

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Check the compression with a hot engine, throttle open, NO CHOKE.
Try again - the bike shouldn't even run with those numbers.......

Rings can get stuck in their grooves after sitting for a long time.
Springs - what springs?????

With guidance from this site, any competent mechanic can rebuild a 450.......
 

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Discussion Starter #4
:D I meant rings, not springs; it was 6 in the morning here when I posted that

As for checking when the engine is hot; it wont fire as of now so checking while hot is not an option.

It has the following new items:
Battery
Coils
Condenser
Spark Plugs
Spark Plug Wires

both spark plugs have spark and now I am currently following your advice on adjusting carbs and timing.
 

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Even really bad rings wouldn't yield zero compression, a leakdown test will help determine the problem, most likely a valve stuck open and/or bent/burned valve.
 

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Discussion Starter #6
Thanks for the suggestions!

I currently have the motor pulled and built a stand for it. I dont really want to tear into it until I have a manual so I wont be able to do much until then. However I am assuming doing this top end rebuild I will need some parts and tools. I have listed below the parts I have gotten or have ordered; if you have any recommendations could you please suggest?

Ordered
2 carb rebuild kits- its needed as well
Top end gasket set
.002 feeler gauge

potential parts/tools
valve spring compressor
 

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wildarmx said:
Thanks for the suggestions!

I currently have the motor pulled and built a stand for it. I dont really want to tear into it until I have a manual so I wont be able to do much until then. However I am assuming doing this top end rebuild I will need some parts and tools. I have listed below the parts I have gotten or have ordered; if you have any recommendations could you please suggest?

Ordered
2 carb rebuild kits- its needed as well
Top end gasket set
.002 feeler gauge

potential parts/tools
valve spring compressor
Mike,

Ain't no valve springs on a 450.....

A warm engine won't do much to improve those compression readings, sadly.

You'll need an alternator puller tool, an oil filter tool, and a cam chain tool.
The first two are cheap, about $10 each from Motion Pro.
The cam chain tool is a lot pricier, but it's the cost of having a 450.......you may find an acceptable alternative on EBay or somewhere else. Experience indicates that it's worth it to get the Motion Pro version, as it's higher quality than some of the chineez junk out there.

If you never plan to do more than the top end, all you'll need is the cam chain tool - but the first two are cheap, and you'll end up needing them sooner or later.........

You have the greatest bike ever made - enjoy the rebuild process and come here for all the help you can stomach.

http://www.motionpro.com/motorcycle/partno/08-0027/



http://www.motionpro.com/motorcycle/partno/08-0015/



http://www.motionpro.com/motorcycle/partno/08-0467/

 

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Discussion Starter #9
do you guys happen to know where i can get the cam master links at? my Local dealer doesnt have any.
 

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wildarmx said:
do you guys happen to know where i can get the cam master links at? my Local dealer doesnt have any.
He just doesn't feel like doing it, as they are still available from Honda.
Get used to being blown off by dealers on your old bike.

Order a couple from BikeBandit or something.....
 

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Discussion Starter #12
I just orderd all of my pro motion tools that you suggested and contacted the ebay seller that gb suggested. He is going to send 3 cam links for 6 bucks. As for my local honda dealer...... he pretty much cut himeself off. At least there is ebay and craigslist :D
 

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I knew that seller would give you a decent deal. I also bought 3 from him for around the same price, and got them really quickly too.

GB :mrgreen:
 

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wildarmx said:
I just orderd all of my pro motion tools that you suggested and contacted the ebay seller that gb suggested. He is going to send 3 cam links for 6 bucks. As for my local honda dealer...... he pretty much cut himeself off. At least there is ebay and craigslist :D
That's too bad about the local dealer. It just goes to show the difference a parts manager can make. I was purchasing from the local dealer on my first project and it was costing a small fortune. I quoted the parts manager the difference between Service Honda and him and he promptly put my name in the computer so whenever I come in my prices reflect the same price that I can get on the web. He now gets all my business, I only use the internet price look up for budgetary purposes.
 

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Discussion Starter #15
yea, i wish my local dealer was a class act but unfortunately hes not. I got pretty much everything I ordered as of yesterday so I will probably start tearing into the engine today :shock: ill post some pics once I get somewhere with it
 

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Looks like you need a valve job.
The cylinder of the piston you marked looks like it still shows the hone marks!!

Take the head to a machine shop you trust and let them do their magic.
 

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Discussion Starter #19
you can see it clearly in the pics below; and when I go talk to the shop, do i need to have any info availalbe for them? ive never had to have this work done before, I just know a good shop... :? and also should I bring all of the parts of my dissasembled top end for them to perform the valve job and test for leaks ect?
 

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wildarmx said:
you can see it clearly in the pics below; and when I go talk to the shop, do i need to have any info availalbe for them? ive never had to have this work done before, I just know a good shop... :? and also should I bring all of the parts of my dissasembled top end for them to perform the valve job and test for leaks ect?
Copy the pages from the Manual that list the specs fpr rings/pistons, as well as valve stuff.
Take any new rings and pistons with you. They will take a series of cylinder measurements - pay particular attention to the spec for cylinder taper, which is very small on a 450. Then make a judgement on a bore job and new pistons.
Most places charge around $40 per hole to bore, new pistons with rings about $100 realistically.

Take all the valve stuff, installed properly in the right places (torsion bars, A and B), as you may have to demonstrate to them how it comes apart. They will test the valves for leaks - from the looks of the photos they'll leak badly.
If their judgement is to cut new seats (if it's even possible), go with it. My shop charges about $35 each to cut in and lap a new seat/valve.
They have precision machines that do all this real good.

You'll end up with a 450 with 180 pounds of compression and run real good.
 
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