This article covers the clutch rubber upgrade process for both the Z & A model CBX.
The CBX1000 Z & A models are notorious for clutch rattle & knocking which often sounds like a serious engine problem. Before we start this process it is worthwhile pointing out that our extensive experience working on these bikes has shown that the clutch rubbers are not the holy grail to resolving the rattle & knocking problem which is often promoted. There are a number of contributing factors, this includes but not limited to the following:-
Carb synchronisation - if the carbs are in good running order and perfectly synchronised most of the rattle and knocking will disappear if the issue is limited to just the clutch rubbers. My test engine runs with worn clutch rubbers, I can audibly hear the carbs are in perfect synchronisation when the knocking disappears. A carb rebuild or synchronisation should be carried out prior to the clutch rebuild to eliminate as much noise as possible. Many people have upgraded their clutch rubbers and have been disappointed with the result when the issue is simply a carb synchronisation issue.
Worn primary chain - there is no real solution to this apart from an extensive engine strip and replacement of the primary chain, the chain can easily be checked but is not covered in this article.
Worn clutch basket fingers with "notching" - when the clutch basket ages the clutch plate "notch" into the fingers, this notching can be removed by carefully filing the notching out. However, this has the detrimental effect of widening the gap between the fingers, once this happens the clutch plates rattle between the fingers to which there is no solution apart from replacing the clutch basket itself. Only a limited amount of notching can be removed in this circumstance.
Starting the upgrade - I am not covering the clutch removal as this is in the factory service manual, I am assuming the clutch has been removed and is ready for the upgrade. The "Z" has 6 rubbers, the "A" has 9 rubbers
The first thing to undertake is removing the rivet heads with a flapper wheel. I use 40 Grit and it takes the heads off in seconds.
Once all the rivet heads are removed the plate should lever off, if you are having difficulty removing the plate centre punch the rivets and relieve the rivets by drilling them through the plate .
Now is the time to grind the remaining rivet to the face of the lugs, this is an important step to remove any possibility of the rivet distorting. Next step is to aid the release of the rivet use a heat gun to get the lug nice and hot.
This next step is extremely important, make sure you use ONLY a flat nose punch, perfect size is 4-4.5mm if not an ordinary centre punch will expand the rivet and possibly crack the lug.
Do not use a pin hammer! Use a hammer on the punch circa 2lb or 1 KG and give it a GOOD hit- it should start moving. This should be the end result... no pictures of the removal process but its self explanatory.
The clutch basket requires no further drilling, you can go straight to tapping, starting with a 6mm taper tap first and finishing with a second tap. Use a pillar drill if you have one to ensure the threads go in square. If you do not have a pillar drill ensure by eye the tap is square in the lug.
Finish tapping all 6 or 9 lugs by hand
Degrease all of the holes with brake cleaner or equivilent, apply a smear of grease to the new rubbers and fit to the lugs ensuring they are the right way around. Fit the gear by easing it and rocking it gently over the new rubbers.
I take a belt and braces approach and slot the ends of the screws, either with a Dremel or by hand with hacksaw to allow riveting them over, not absolutely necessary but security and peace of mind.
OK now is the time fit the screws using thread locker
Fit the srews and tighten them down, then you can rivet the slots as previoulsy mentioned.
So that is the job basically finished with the exception of removing some of the head of the bolts to miss the oil catch cage behind the clutch.
This is the finished product ready for fitting I quite often do 2 or 3 at a time. If you wish us to undertake this for you contact firstname.lastname@example.org