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Discussion Starter · #1 ·
Hi!

My name's Hugo and I'm currently living in London Uk.

I'm rebuilding a CB500T and I've got just a quick question for the experts.

Yes, I know this is the 450 place but I'm kind of desperate with this one.

I'm in the process of putting a new cam chain on and cannot get the camshaft marks to align perfectly with the bearing marks. They both stay about 1mm off when the rotor is in LT position. I've got the chain and tensioner on.

Do they align perfectly?

Thank you in advance for your time and patience.

Hugo
 

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Sensei
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They NEED to align perfectly.....This is your primary engine timing...... Take tensioner off, break chain and reset.....
 

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Discussion Starter · #3 ·
Thank you for your reply!

I've tried that. 1 tooth forward and 1 backwards and it NEVER aligns perfectly...:S

And dont have the camera here...:S

The intake camshaft aligns with the LF rotor mark and the exhaust aligns with the LT...
Strangest thing
 

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Sensei
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You have too many links BETWEEN the cams, or the chain is "stretched out".... Hold one cam and the LT mark in alignment with their indexes, and skip the chain on the other camshaft until it's aligned .... Marks must be aligned, but if your chain is worn, they MAY stray a bit, (but should/must be still touching the indexes if not perfectly centered in them).....(That is to say they may vary by the "line" width of the marks)
.....If you still can't get alignment, replace the chain.....
 

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Sensei
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You'll need to skip the intake cam to achieve alignment......Try to set it on the mark, but a smidge "over" as it will counter-rotate a smidge when the chain adjuster is re-installed.....Let me know if you are sucessful....
 

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Discussion Starter · #7 ·
Ok...

from the beggining... I've done all that, still cant find an exact alignment in the marks.
I can align the LT with the exhaust, but the intake always sits 1 or 2 mm up the mark or 3 or 4 mm down. It would seem too me like I would need to skip half a tooth in the chain to get it right.

Everythingn is new, including gaskets top and bottom.
 

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Did you remove the cam chain tensioner completely?
 

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Discussion Starter · #9 ·
Yes, indeed, I did.

From my calculations , this will never align correctly.

The engine was seized when I got it, so there wasnt a way to check timing before taking it appart. It's got low miles (16k I think) so there's no wear in the sprockets and the timing chain is brand new.

I'll post some pictures in the morning so you can draw your own conclusions.

Thanks for your inputs on this one.
 

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For a start check that small idler in top of head is running on its shaft
I managed to misalign this and nothing would line up.
From the top:
assuming crank is on correct marks and exhaust cam is aligned pull chain over exhaust cam
spend next hour or so fiddling it back to inlet cam, lay over top of cam, pull other end of chain up and wrap around
remainder of cam wheel with the adjuster out.
If you cant get them in line with marks you have something seriously misaligned.
It sounds easy but it has taken me an hour before just lining it up.
Keep us informed.
 

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Discussion Starter · #11 ·
Bike-Mart said:
For a start check that small idler in top of head is running on its shaft
I managed to misalign this and nothing would line up.
How can this possibly go wrong? Could you be a bit more specific abou this one?

Thank you
 

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It is possible to have the wheel wedged up in the tunnel next to the shaft, obviously only if you removed it.
I did and spent ages trying to figure out why nothing would fit.
 

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Discussion Starter · #13 ·
I did have it out because this is a complete engine overhaul.

What you're saying makes sense in my case , because it looks like the roller needs to be sligthly smaller in order for the chain to gain some slack and the camshafts reach the marks.

I'l check it tomorrorow , although I cant see how the thing can be "wedged up" if the shaft is in place and all the way in.
 

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Take my word for it, it is possible even the shaft goes fully in and that seems to stop the wheel from falling.
Good luck
 

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Sensei
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I was just reminded of a recent similar problem that turned out to be the wrong chain.
This happened to a professional Honda mechanic who attempted to use a chain that apparently had been either mislabeled or mismanufactured (or both).....Even the slightest deviation from original specs can "add-up" over the number of links and result in the "1/2 tooth off " error.... Try fitting the original chain and see if it "cures" the problem......
 

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Hi,

I'd let her rip at that. Of course turning over by hand carefully first - just in case

Good luck!
 

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Sensei
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If those pics were all shot at the same time (without any rotation) it is in time...
 

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Discussion Starter · #19 ·
They were,

THANK YOU VERy MOOOOOOOCH!!!!!!!!!

I'll start a new thread soon with the rebuild with millions of pictures.

Meanwhile you can catch it here:

cestosteam.blogspot.com
 

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I'm confused, what did the original question pertain to? I had assumed he knew what marks to align but couldn't get the cam chain to connect without moving one of the came a few degrees.

Ok, Ok, Mike, let a sleeping dog lay.
 
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