dammmm i love this forum...........

 

On the old Yamaha XS750 triples there was a spring loaded plunger based CCT. The drill was to manually rotate the engine till there was maximum slack on the CCT side of the chain. Loosen the bolt that kept the plunger locked in position. The spring would apply the correct pressure to the plunger then you tightened the bolt to hold the plunger in position. Always worked great, with no problems. Wish we had the same system on the VTR.

 

So, a little more research to add to this. I had a front cct failure. When I removed both ccts, the rear drained out a pool of oil while sitting on the bench. The front...none. I wonder what the result would be to squirt some oil into the back of the front cct every oil change. Just a thought.

 

wouldn't it be easier to just do a stoppie every now and then?

 

nope, because the cam chain tensioner is on the rear. You would have to go past 12 oclock to oil it.

 

**** that. i ain't goin past 10....who needs oil in the cct anyway? It's just a stop bolt.

 

there is no ratchet, take one apart and look at it. it has a screw thread, and it gets gummed up on the front cct b/c it gets no oil splash like the rear cyl gets.

UPDATE

i have a newly modified oem CCT on my bench right now that i will put in before winter is over.

i put the screw on my lathe and drilled a small hole down the center and milled an intersecting cross hole just before where the thread begins. i have always put oil in mine every oil change since i first serviced the CCT, with this new cross hole design the oil will drench the threads according to my bench test much better than it does now.

there are many theories about the failure mode here, none are proven......but i believe (don't know for sure) it is all related to lack of oil. when i took the front CCT out for the first time many years ago b/c of noise, it was seized and gummed up. the rear CCT is full of oil all the time.

the screw material is case hardened, so if you want to drill it, you will have to use a carbide drill to get the holes started.

don't think any of you guys will believe it, but the screw does rotate in both directions during operation with respect to temperature. i bored a hole in the sealing screw in the CCT and machined a little shaft that keys into the slot, put on a little disk with marks on it. when the engine is cold started the screw jumps CCW about 1/8 turn to take up the slack from when it was hot, as it warms up the it very slowly turns the other direction. you can't see it turn, thats why the disk has marks on it, it takes a while. sure wish i had taken a video. based on this experiment i would never use manual cct. these OEM are designed to move as req'd.

so when they get gummed up, they never take up the slack after a thermal cycle, the gap eventually gets too large and whack, you need new valves.

flame away!

 

The Poll doesn't show any 2004's that failed.

Forum member "Squid" had his 2004 fail with 7k miles last week.
I know of another 2004 in the Bay Area that failed at 12k miles.

 

+1 , and thanks alot, for not asking for everyone 's opinion on oil and tires too.