Topic: Is that part of the cam chain tensioner in the oil pan?

[Rocketman]

Was doing my Barber post race tear down and found what appears to be part of the cam chain tensioner in the CB550 oil pan.  Don't have a sample to compare it to, but don't know what else it could be.  Good news is the bike was running strong at the end of the race, so hoping the damage is minimal.



If it is the tensioner, is anyone aware of any alternatives?  I know B Waller was working on something.

[bwaller]

That's exactly what it is.    Out of curiosity was this an OEM blade or a David Silver "pattern" piece?

Not that it made any difference in my case, I was breaking one every race.

Usually they break closer to the end and only a little tension is lost. By the looks of that one it should exhibit quite a bit of chain rattle, or at least more than normal now that you know what has happened. Maybe you won't be starting it again to check....and again who cares right?

I used a tensioner from a different manufacturer this season. I want to do a leakdown before dismantling so I cannot say how it looks yet. I'm better able to get to work on it, maybe this weekend, so stand-by if you don't mind Martin and I'll fill you in.

[Rocketman]

It was an OEM part.  Maybe I should be thankful it lasted 5 races.  Season is over and next race will probably be Road America next June, so no rush on the repairs.  Very interested in what you find when you get a chance to open your motor.  Thanks!

[turboguzzi]

wow, lucky guy! that thing wedged between gears wouldnt be so funny... good prevention is to have a magnetic drain plug, tells you also if any other steel pieces are slowly disintegrating

[bwaller]

Breaking is one thing, but it's actually odd it dropped out of the damper. They seat snuggly into those spots and I've noticed  even when broken the end "stays put".

[Rocketman]

Pulled the head over the weekend and here is what I found.



The Slipper has fallen out of the Tensioner!  Here is a photo of the broken Slipper and Tensioner. 



The cam chain was wearing on the top of the Tensioner.  Explains the steel slivers that were also in the pan.  Adding a magnetic drain plug is on my must do list.  Thinking if I go back with a Honda Tensioner a bolt and locking nut that captures each end of the Slipper in the Tensioner may be a good idea.

[bwaller]

This is odd, are the dampers in place in each end of the tensioner? Usually installing the blade takes some force to seat the rounded end in the damper. Every time I broke one it was at the top, very near the end and that rounded section was still in the damper. (and would never fall out)

I'll have some tensioner news shortly.

[Rocketman]

The rubber dampers are in place.  Never paid much attention to how the Slipper seated in them.  Maybe I did not have it fully seated?  Will be sure to do so in the future.

[iomtt9]

We have found that when new blades were bought a few have broke, but when we used 2nd hand ones they have lasted, and up to now, none have ever broke.
Some of the 500/4 engines i have built now, have different tensioners in them, just wondering if this is the same as what Brent is about to come up with. The ones we use are from a Honda 600F N4. Not had a problem with them.

[turboguzzi]

We have found that when new blades were bought a few have broke, but when we used 2nd hand ones they have lasted, and up to now, none have ever broke.
Some of the 500/4 engines i have built now, have different tensioners in them, just wondering if this is the same as what Brent is about to come up with. The ones we use are from a Honda 600F N4. Not had a problem with them.

colin, 600f n4 uses same engine as the CBR600, and yes, i used the same tensioner. not exactly a bolt on, needs some tinkering to fit, but not rocket science either, like colin's, it never gave trouble. in one of my old build threads there should be pics....

[Rocketman]

Gentlemen, Thanks for the tips on the CBR600 tensioner.  The part number changed from 14510-MEE-000 to 14510-MFJ-D00 in 2007.  Assume it is the later part.  Found your post Turboguzzi "More 500 Racer Development". http://forums.sohc4.net/index.php/topic,55162.msg593604.html#msg593604  Your description of the modifications are helpful.  Will see how Mr. Waller's experimental tensioner held up this year and then figure out how I want to proceed.

[bwaller]

I'm waiting to hear back from Gerrit about the tensioner. It was his idea.... Martin the CBR600 tensioner I worked with was 14510-MAL-601. It seems to be quite different from the two numbers you posted. Sorry be back soon.

[Rocketman]

Seems Honda changed the tensioner several times over the years. Hard to tell from the diagrams, but they all appear similar. No worries, have all winter to get this sorted.

[turboguzzi]

go for 2nd series cbr600 / hornet 600f motor.

get a cheap one form ebay to see how it fits, most likely it will be as new...

it's on the limit of being too long, ive cut the non hinged tip i remembrr right

[bwaller]

Instead of running amuck in your thread Martin I showed discussed and posted some tensioner pics here.

http://forums.sohc4.net/index.php/topic,83871.msg1858034.html#msg1858034