View Poll Results: What year was your bike which had CCT failure?
1997
2
7.69%
1998
8
30.77%
1999
5
19.23%
2000
1
3.85%
2001
1
3.85%
2002
3
11.54%
2003
2
7.69%
2004
1
3.85%
2005
0
0%
2006
0
0%
2007
3
11.54%
Voters: 26. You may not vote on this poll
CCT Failure frequency
09-30-2010, 03:01 PM
#62
Junior Member
Squid
Join Date: Aug 2010
Location: Discovery Bay, CA
Posts: 15
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.
09-25-2011, 06:54 PM
#63
Senior Member
SuperBike
Join Date: Mar 2007
Location: Belgium, WI
Posts: 1,611
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.
09-25-2011, 08:24 PM
#64
Senior Member
MotoGP
Join Date: Aug 2006
Location: altoona, pa
Posts: 2,934
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.
09-25-2011, 08:45 PM
#66
Senior Member
MotoGP
Join Date: Aug 2006
Location: altoona, pa
Posts: 2,934
09-28-2011, 06:57 AM
#67
Junior Member
Squid
Join Date: Jul 2011
Location: nor cal
Posts: 21
Huh?
I don't think it has so much to do with age or mileage as it does with poor design. Most are not changing out old OEM CCT's for new, questionable OEM CCT's... They're replacing them with bulletproof, manual CCT's with a better, simpler design and a proven track record. The design flaw with the OEM CCT is not the spring.. it's the ratcheting mechanism itself. The teeth round off from the beating they get from the big twin making them unable to hold their place.
I didn't catch any "smart ***" comments when re-reading the thread... only useful, helpful info. Please point out the Smart *** comments for the rest of us.
I don't think it has so much to do with age or mileage as it does with poor design. Most are not changing out old OEM CCT's for new, questionable OEM CCT's... They're replacing them with bulletproof, manual CCT's with a better, simpler design and a proven track record. The design flaw with the OEM CCT is not the spring.. it's the ratcheting mechanism itself. The teeth round off from the beating they get from the big twin making them unable to hold their place.
I didn't catch any "smart ***" comments when re-reading the thread... only useful, helpful info. Please point out the Smart *** comments for the rest of us.
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!
Last edited by chp_hates_me; 11-21-2011 at 04:18 PM.
11-16-2011, 09:38 AM
#69
Senior Member
SuperSport
Join Date: Mar 2010
Location: Asheville, North Carolina
Posts: 949
Thread
Thread Starter
Forum
Replies
Last Post
Scoutpilot
General Discussion
7
10-03-2008 09:36 PM
BiggDaddyKool
Classifieds
10
05-31-2007 01:36 AM
