Top end rattle

[Flynt]

If it gets spooled up enough to have valve float, the shim losses contact with the cam lobe.

How "spooled up" do you need to be for that?  I'm running around at 6-8K with occasional 9K+ bursts these days...  did you make my beasty float proof?

Frank

[andyb]

High revs and old valvesprings aren't a good combination. 

[Pat Conlon]

....and if your valves are loose to begin with...

[racerrad8]

How "spooled up" do you need to be for that?  I'm running around at 6-8K with occasional 9K+ bursts these days...  did you make my beasty float proof?

Frank

Yes, you have better valve springs and you can run up to the red-line without any issue. The issue is the old, stock 20-30 year old valve springs that loose there seat pressure and let the valve(s) float.

Pat, in my experience, it has nothing to do with valve adjustment but more of the lack of ability of the valve spring to keep the valve seated when it slams closed. The valve actually will bounce back open and the shim which is dislodge from the bucket can now pop out.

Randy - RPM

[Pat Conlon]

Okey doke....Spitting shims: is that why racers convert over to shim under bucket?

[JMR]

 That tensioner design is pretty good IMO. I have had the rubber tip disintegrate which used up all the travel but it still applied tension on the blade.

[JMR]

Okey doke....Spitting shims: is that why racers convert over to shim under bucket?

That's what I did Pat. The real plus is the shim is so much smaller (and lighter) than the original. My uses the 13mm shim but the newest retainers us the 9mm shim. That and the Ti retainer lighten the assembly by quite a bit. The problem I have seen with the SOB Ti retainers is they can "egg" out especially on valvetrains with steep valve angles. You'd think it wouldn't make a difference as the bucket is taking all the side load but that's what I have experienced. I'd recommend getting the retainers Ti nitrided or better yet DLC. These are the best solution as the retainers are steel. They aren't available for the FJ (as far as I know) and are very pricey as you still have to purchase the buckets.  http://japan.webike.net/products/9513304.html

[Pat Conlon]

Thanks Mike, that's interesting....
I guessing the major draw back on the shim under bucket design (for street bikes) would be that every time you do an adjustment, you have to remove and reinstall the cams...and all that involves.
Also... I've always wondered....To distribute the wear from the cam lobes, with the shim under the bucket, do the buckets rotate as freely as the shims do (when the shims are over the bucket)

Good stuff...

[andyb]

Honestly, it takes less time to pull the cams than you'd think.  Just shimmed mine (mostly, have to order an oddball size apparently), and found it vastly faster to just measure everything and pull the cams.

Once you've got the crap out of the way, same as if you were using the normal tool hold-down thing, ziptie the camchain tightly to the sprockets, remove the tower (four bolts), remove the tensioner (two bolts) and then pull the camcaps off.  Easy, and means that you can cruise through the swaps very rapidly, though I had to change a rather high number of shims.  If I was doing just one or something, it'd probably have been the hard way to do things.

[JMR]

Honestly, it takes less time to pull the cams than you'd think.  Just shimmed mine (mostly, have to order an oddball size apparently), and found it vastly faster to just measure everything and pull the cams.

Once you've got the crap out of the way, same as if you were using the normal tool hold-down thing, ziptie the camchain tightly to the sprockets, remove the tower (four bolts), remove the tensioner (two bolts) and then pull the camcaps off.  Easy, and means that you can cruise through the swaps very rapidly, though I had to change a rather high number of shims.  If I was doing just one or something, it'd probably have been the hard way to do things.

I agree especially on the FJ as there is plenty of room to work. The method you describe is spot on.

[JMR]

Thanks Mike, that's interesting....
I guessing the major draw back on the shim under bucket design (for street bikes) would be that every time you do an adjustment, you have to remove and reinstall the cams...and all that involves.
Also... I've always wondered....To distribute the wear from the cam lobes, with the shim under the bucket, do the buckets rotate as freely as the shims do (when the shims are over the bucket)

Good stuff...

Yes Pat...the buckets still rotate. The very small angle ground into the cam lobes is what cause the spinning. Yoshimura has always made nice mechanical pieces. They are hooked up with the same Japanese manufactures that produce OEM equipment.

[Pat Conlon]

Yea but....to get to the cam chain tensioner you have to pull the carbs and heat shield off......

I agree....you can say that everything's out of the way..... Everything.

Thanks for the answer Mike...

[JMR]

Yea but....to get to the cam chain tensioner you have to pull the carbs and heat shield off......

I agree....you can say that everything's out of the way..... Everything.

Thanks for the answer Mike...

Very true my friend. BUT...if you have ever had to work on a modern CBR, GSXR or R1 you would change your mind. Those things absolutely blow to work on starting from removing the body panels Pat. No room once you are in there too. The FJ is like working on the Ponderosa.....big and rangy. And I know you know what the Ponderosa is.

[JMR]

Yea but....to get to the cam chain tensioner you have to pull the carbs and heat shield off......

I agree....you can say that everything's out of the way..... Everything.

Thanks for the answer Mike...

Very true my friend. BUT...if you have ever had to work on a modern CBR, GSXR or R1 you would change your mind. Those things absolutely blow to work on starting from removing the body panels Pat. No room once you are in there too. The FJ is like working on the Ponderosa.....big and rangy. And I know you know what the Ponderosa is.

Just like the Australian's like it judging by "Whole Lotta Rosie". Love that song.

[Ront]

I think I found the cause of my rattle. The tensioner is fully extended and there's still slack in the chain. Bad news