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Discussion Starter · #1 ·
Hi,
I am in the process of rebuilding my engine after lapping in the valve seats,after putting the inlet side together and adjusting the clearance between lobe and follower to 1.5 thou, i find the timing marks do not align( see photo if its got there).
When i align the marks the inlet valve is starting to open, anybody got any ideas as i am rapidly losing the will to live!
Thanks
Phillip
 

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I spent a couple of hours over the weekend adjusting my valves and ignition timing and realized that I had the same problem. I assumed similarly to tbp that I had a stretched (old) cam chain. I was going to try to loosen the tensioner and rotate one of the cams to bring it into better alignment. Let us know what solution ends up working for you.
 

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Sergeant Pepper said:
... I assumed similarly to tbp that I had a stretched (old) cam chain. I was going to try to loosen the tensioner and rotate one of the cams to bring it into better alignment. Let us know what solution ends up working for you.
Not what I was assuming at all, I wasn't assuming anything...just asking.

Recently I encountered a new "450" cam chain that was the wrong chain in the right box.
Close, but no cigar, took a while to figure it out.

The chains have real small numbers stamped on them, I failed to check and just assumed it was the right chain - my bad.

Didn't want to cloud the issue with needless info if the Poster didn't use a new chain.
 
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I am having the exact same problem and by the looks of your index marks it is at the same position. The valves begin to open when you do get the marks lined up and it pops the shaft right back to that position.
Should the tensioner be off?
219t is the cam chain that I put on.
 

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Discussion Starter · #8 ·
Hi,
The photograph was taken with no chain attached, head off the bike, that is as far as i could rotate the cam with my hand, I should have mentioned that in my original post, but unfortunately i am on the nightshift this week and i am not at my best when on nights!
Can someone tell me the position of the left side valves when the lt marks are in the correct position and the lefthand piston is at tdc.
I have it in my mind that both valves should be shut when the mark on the cam lines up with the one on the bearing housing, but when my marks align the inlet valve has started to open.
Now i am hoping this is how the big "H" designed it and i have nothing to worry about? it is getting a genuine Honda cam chain and link (bought ftrom silvers last week)
Another query is the camshaft endfloat, this has now decreased because of the different thickness used on the gasket set i bought (thinner) which has resulted in a gap of .002 thou which according to the book is the lower limit for end float .002-014 thou.
Should I leave it as it is or remove the shim to give me another .004 (.006) in total, which would be near to the middle of the factory limits.
Any answers gatefully recieved.
Thanks
Phillip
 

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I would remove the shim..... (when parts are fully seated/tightened the gaskets will compress somewhat)
MY question is why/how were the valves adjusted before installing the camchain?...You'll probably have to back them off (have them fully "loose") to install the chain anyway, so your "problem" doesn't actually exist..... I adjust the valves after the chain and tensioner are installed
 

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66Sprint said:
I would remove the shim..... (when parts are fully seated/tightened the gaskets will compress somewhat)
MY question is why/how were the valves adjusted before installing the camchain?...You'll probably have to back them off (have them fully "loose") to install the chain anyway, so your "problem" doesn't actually exist..... I adjust the valves after the chain and tensioner are installed
I also have the same cam mark to index mark as you have ! it is off just a bit on the intake cam,
the exhaust is right on all with LT mark aligned at left cylinder TDC. This is on an engine with
11K original miles and all parts mic to within allowable specs. I did replace the timing chain with a Tsubaki BF50M and just can not get the intake cam to perfectly line up with the index mark. The tensioner is not installed.
I have not staked the master link yet, rotation of the crank through all four cycles has all valves opening and closing correctly! Bill or Steve, have you had any luck with one like this? I have tried rotating the intake cam one tooth and it puts it off an equal amount in the opposite direction.
This is a pristine 71 CL450 all original and ran great after cleaning the carbs so the top end freshening was a precaution. Also it is a one owner and he said it had never been apart and it is obviouse. I do not want to stake the master link until I have exhausted all avenues. Any
suggestions?
 

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fasteddie1947 said:
I also have the same cam mark to index mark as you have ! it is off just a bit on the intake cam,
the exhaust is right on all with LT mark aligned at left cylinder TDC. This is on an engine with
11K original miles and all parts mic to within allowable specs. I did replace the timing chain with a Tsubaki BF50M and just can not get the intake cam to perfectly line up with the index mark. The tensioner is not installed.
I have not staked the master link yet, rotation of the crank through all four cycles has all valves opening and closing correctly! Bill or Steve, have you had any luck with one like this? I have tried rotating the intake cam one tooth and it puts it off an equal amount in the opposite direction.
This is a pristine 71 CL450 all original and ran great after cleaning the carbs so the top end freshening was a precaution. Also it is a one owner and he said it had never been apart and it is obviouse. I do not want to stake the master link until I have exhausted all avenues. Any
suggestions?
Exactly the situation that occurred when I tried the mis-labeled cam chain - everything lines up except the intake cam.

Again, the cam chain should be marked "219" - the one I fought with was marked "29H".
It's obvious that the 29H chains are slightly different, and just won't work on a 450. Sad, because they're commonly advertised on EBay as the right part, but they're not.
The 29H chain I tried is still in a box under my work bench, along with other wasted-money stuff.
I stupidly tried changing out all sorts of stuff before putting the old cam chain back in - when I did everything lined up perfectly (DOHHHH !!!).

Your options are to either get the right chain (big bucks from Honda, or else examine before you buy aftermarket) or to just use the old one if you're tired of the whole thing.
I've never encountered a "BF50M", so have no direct experience with them - but it looks like it's not right either, based on what you're reporting.

If the marks don't line up I would avoid turning the engine over at all..........

On a positive note, I don't think I've ever personally seen a 450 cam chain that broke (though I've heard anecdotal reports to that effect), and I've worked on a lot of 450's. They get loose and flop around, messing up plenty of other stuff, but they're much tougher than they look and rarely break.

There's more on this stuff at http://home.comcast.net/~tbpmusic6/450site.htm
 

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tbpmusic said:
fasteddie1947 said:
I also have the same cam mark to index mark as you have ! it is off just a bit on the intake cam,
the exhaust is right on all with LT mark aligned at left cylinder TDC. This is on an engine with
11K original miles and all parts mic to within allowable specs. I did replace the timing chain with a Tsubaki BF50M and just can not get the intake cam to perfectly line up with the index mark. The tensioner is not installed.
I have not staked the master link yet, rotation of the crank through all four cycles has all valves opening and closing correctly! Bill or Steve, have you had any luck with one like this? I have tried rotating the intake cam one tooth and it puts it off an equal amount in the opposite direction.
This is a pristine 71 CL450 all original and ran great after cleaning the carbs so the top end freshening was a precaution. Also it is a one owner and he said it had never been apart and it is obviouse. I do not want to stake the master link until I have exhausted all avenues. Any
suggestions?
Exactly the situation that occurred when I tried the mis-labeled cam chain - everything lines up except the intake cam.

Again, the cam chain should be marked "219" - the one I fought with was marked "29H".
It's obvious that the 29H chains are slightly different, and just won't work on a 450. Sad, because they're commonly advertised on EBay as the right part, but they're not.
The 29H chain I tried is still in a box under my work bench, along with other wasted-money stuff.
I stupidly tried changing out all sorts of stuff before putting the old cam chain back in - when I did everything lined up perfectly (DOHHHH !!!).

Your options are to either get the right chain (big bucks from Honda, or else examine before you buy aftermarket) or to just use the old one if you're tired of the whole thing.
I've never encountered a "BF50M", so have no direct experience with them - but it looks like it's not right either, based on what you're reporting.

If the marks don't line up I would avoid turning the engine over at all..........

On a positive note, I don't think I've ever personally seen a 450 cam chain that broke (though I've heard anecdotal reports to that effect), and I've worked on a lot of 450's. They get loose and flop around, messing up plenty of other stuff, but they're much tougher than they look and rarely break.

There's more on this stuff at http://home.comcast.net/~tbpmusic6/450site.htm
Bill,
Thanks I am going to thread the old chain back on and check the marks. I am not against buying another new chain and will look for one with the 219 marking. By the way the Tsubaki chain # is BF05M not BF50M as previously stated.
I tried to open your site however my macintosh computer said the file may be corrupted ?
I am a firm believer in checking human error first and going from there, I bet I do have an incompatible chain even though it fits !
 

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fasteddie1947 said:
I tried to open your site however my macintosh computer said the file may be corrupted ?
I am a firm believer in checking human error first and going from there, I bet I do have an incompatible chain even though it fits !
Must be a Mac thing - the web site is fine, just checked it......sorry.
 

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tbpmusic said:
fasteddie1947 said:
I tried to open your site however my macintosh computer said the file may be corrupted ?
I am a firm believer in checking human error first and going from there, I bet I do have an incompatible chain even though it fits !
Must be a Mac thing - the web site is fine, just checked it......sorry.
Bill,
It was an old mac thing! opened fine on my wifes new one.
The problem was not my new Tsubaki chain BFo5m, it was that I was 180 out on LTC. Once I realigned everything
on the correct stroke (as your article states) all marks are spot on and all valves open and close at the right time.
Valves are adjusted and the engine is ready to go. I will crank it over with the e-button until I see oil coming out of the cams before firing.
Thanks again.

Ed
 

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You may have to crank for quite a while before seeing oil come out on your cams, your battery won't like it much. I've heard anything from 90 seconds to some minutes for oil to get up there - though I've never tested for it so I can't be definitive. Then it has to get through the cam journals, into the cam, out the tiny holes, etc.
Try loosening that great big nut on the back of the tach drive after starting it up - use gobs of assembly oil first, it will protect things for a good while. You should see lots of oil come out there as soon as it gets to the top end.

I'm at a loss to explain how being on the wrong stroke would make your cam marks not line up. Moving 360 degrees on the crank would make exactly the same teeth on the crank sprocket present themselves to the cam.
So it sort of doesn't make sense to me.

But all that matters is you got the cam timing nailed down now.......
 

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Hi,

For a bomber the time that oil reaches the head is around 90 seconds or even longer (when started in cold weather).

Jensen
 
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