I got a small and big surprise today when removed the head and was going to remove the cyl block.
1.)
The cam chain tensioner upper wheel had cracked in 2 pieces. The 2 rubber parts were blocked between tensioner and cyl side above the tensioner adj hole.
The tensioner had around 5500kms + revving when adj carbs. Lets say max 6000kms which is nothing. The old Honda tensioner had 35.000kms and still instact except for the hard rubber and the usual rubber rubbing.
I checked my old receipts so I do not say wrong. Tensioner was Cam chain tensioner kit from vintagecb750.com bought summer 2012. I remember that I saw a label with made in Taiwan. I had that in my mind and had plan to replace it this winter. New Honda tensioner waiting in a box with many bags and boxes marked with Honda.....
I did not had in my mind that the wheel should crack in 2. The rubber parts blocked the tensioner which explain the hard chain at last cam change. Removal of tensioner adjuster did not release as much I rembered it should. I blmaed the new HD cam chain...
This means that the wheel broke at around max 3000-4000kms!!!!
Real crap!!!
The only thing I can say to all that has installed this crap: Pull engine and install the correct thing before it turns expensive. I doubt this is one single case. Wrong type of rubber
2.)
Before when removing my carbs. Cracked carb boots. The very cheap ones from Cruzinimage. I tested to see if they should keep together. For that price probably not and I was right. These have around 2000kms. 2 of the boots with deep cracks.
I have used same clamps on my OEM carb boots that have no cracks at all with OEM carbs and around 35.000kms.
I planned to replace them. I have NEW Honda carb boots waiting. Fuel used all the time is Shell V-power. Maybe strong stuff?
Cheap China fuel hose will not withstand either. Replaced by real USA made fuel hose from Gates that is OK, Barricades.