Cam Chain Tensioner

[renelle]

What an honor the have the first technical related post here...

There have been some postings on the old forum already about the Cam Chain Tensioner (CCT) and the problems related to that. I have no history about my 1999 Varadero, so don't know if my bike has had the modification. The last trip I thought I heard some rattle from the back cylinder, so bases on all that info, I decided to check the CCT's. I read about the possibility to only replace the springs (see link below). So based on the low costs for the springs, the strategy was to try this first.   

http://varaderoforumcom.h826747.serverkompetenz.net/viewtopic.php?t=919&highlight=cct

I've made the special release tool fist. Then removed the two CCT's. For the back CCT, I unscrewed the brake pipe's so I had more space to unscrew and remove the CCT. For the front CCT the tank and airbox needed to be removed. No need to remove the carburetors. See the pictures...

When I removed the CCT's I noticed the front was almost dry from oil. It was dirty and even a bit corroded on the inside! The back CCT was well oiled. The position of the CCT's explains this difference and it's makes sense that the front CCT will be the first one that stops working.

When I started the replacement of the springs, I noticed the new springs were a bit different. The new ones have a larger "hook" at the end and are thinner (new:0,7mm / old:0,8mm). It fit's, but the differences made me wonder what to do: clean everything and simply re-use the old spring or use the new one.

Could it be the new spring is the one for the modificated CCT? I read somewhere there has been a modification, does anyone know what the modification was?

The safest way of course is simply order two new complete CCT assemblies, but maybe someone can help me with the questions I have...

 
 

[renelle]

Some additional pictures of the differences in the springs...

First the original spring, then the new one mounted...

[V Saarela]

As our Canadian friend Jasper wrote in his introduction something like this....great with new start, now we can start all over again 


Looking good, but....why only change the springs? (yes, understand for the cost)

Your tool is looking professional made 

My was like this, made with a beer in the other hand 




....and reused to an another bike(looks like two beer in my hands)



Still, they worked out well

[Two Plugs]

Tnx, very valuable posting! We changed our CCT on Karinda's MK1 at the 150.000km marque - not that it was necessary, but purely to be on the safe side (the rattling noise started every now and then which is a good indication for approaching CCT disaster )

I noticed that the new CCT's are quit a lot smaller than the old ones which have been replaced.

[Jasper]

I posted something in the Old Forum.
I didn't remove the CCT but made the "locking tool" for work on the valve shims. ....looks like mine was made from a beer can

@ saarela
...so, do we need to repeat everything or can we create links to topics in the "Old Forum" ?

[V Saarela]

@jasper, maybe we shouldn´t destroy renelles threeth, but I wonder to what the forumteam will do. Linking to the old one would look ugly.

Still, I´m wondering if people replace only the springs or the whole tensior?

[renelle]

I've searched the old forum for information about the CCT's. Wanted to know why they fail and if I could see (by opening them) if I could see if the CCT's of my Varadero needed replacement. To be honest... I didn't find much on the old forum that answered my questions. If I have missed something and this information is available on the old forum, maybe someone can add the links to those posts...

Because I found a post of someone that successfully replaced only the spings and I found several stories about CCT's failure caused by broken spings, I thought it would a good idea to start by replacing the springs. They only costed a few euro's...

While working on this replacement job I found out the "new" springs were different from the original's. Because the only "damage" I could see, was an internally corroded front CCT and the "new" springs were different from the original's, I concluded it was better to replace the complete CCT's with new ones.

I've replace the complete CCT's with new ones some week's ago, so that answers the question about why to only replace the springs.

Before I replaced the old CCT's with the new complete CCT's, I disassembled also the new one. I've measured the sping and found out the new complete CCT's contained the same spring as the original (0,8mm). So that means the spring that I've ordered is NOT the same that is originally used for the new CCT's. When retracting the plunger of the CCT with the special tool, the spring felt a lot stronger than the old CCT.

Based on my experience, I would suggest the best solution is to replace the complete CCT. Two reasons:
- The springs I was able to order separately differ from the originals. The appear not to be the correct ones...
- Because  the front CCT was internally corroded, the only way to solve this is to replace the complete CCT.

[jackyork]

Interesting and important topic raising the following questions;
#1. Did you resolve the lack of oil resulting in corrosion of the front CCT? Is it due to a blocked oil-way?
#2. In the forum on oil preferences, Two Plugs says he only changes the oil at 2 years. This could be a cause of such a routine. Fully synthetic is without doubt the most protective and long lasting but after 12 months any oil will contain harmful acids and deposits due to the combustion process. If you use good quality oils and change more frequently, this is more protective than top quality oils run to death. If you take the bike off the road (not off-road) for the winter, the oil & filter should be changed before storage so that the engine sits in nice clean oil.
#3. I think there must be a mistake in the statement that trucks last longer on semi, rather than full synthetic oils.